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1. The CARMENES search for exoplanets around M dwarfs: A deep transfer learning method to determine Teffand [M/H] of target stars

Author: Ministerio de Ciencia e Innovación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Junta de Andalucía, Consejo Superior de Investigaciones Científicas (España), Max Planck-EPFL Center for Molecular Nanoscience and Technology, Bello-García, A., Passegger, V.M., Ordieres-Meré, J., Schweitzer, Andreas, Caballero, J. A., González-Marcos, A., Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cifuentes, C., Henning, Thomas, Kaminski, Adrian, Luque, R., Montes, D., Morales, Juan Carlos, Pedraz, S., Tabernero, H. M., Zechmeister, Mathias, Ministerio de Ciencia e Innovación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Junta de Andalucía, Consejo Superior de Investigaciones Científicas (España), Max Planck-EPFL Center for Molecular Nanoscience and Technology, Bello-García, A., Passegger, V.M., Ordieres-Meré, J., Schweitzer, Andreas, Caballero, J. A., González-Marcos, A., Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cifuentes, C., Henning, Thomas, Kaminski, Adrian, Luque, R., Montes, D., Morales, Juan Carlos, Pedraz, S., Tabernero, H. M., and Zechmeister, Mathias
Abstract: The large amounts of astrophysical data being provided by existing and future instrumentation require efficient and fast analysis tools. Transfer learning is a new technique promising higher accuracy in the derived data products, with information from one domain being transferred to improve the accuracy of a neural network model in another domain. In this work, we demonstrate the feasibility of applying the deep transfer learning (DTL) approach to high-resolution spectra in the framework of photospheric stellar parameter determination. To this end, we used 14 stars of the CARMENES survey sample with interferometric angular diameters to calculate the effective temperature, as well as six M dwarfs that are common proper motion companions to FGK-type primaries with known metallicity. After training a deep learning (DL) neural network model on synthetic PHOENIX-ACES spectra, we used the internal feature representations together with those 14+6 stars with independent parameter measurements as a new input for the transfer process. We compare the derived stellar parameters of a small sample of M dwarfs kept out of the training phase with results from other methods in the literature. Assuming that temperatures from bolometric luminosities and interferometric radii and metallicities from FGK+M binaries are sufficiently accurate, DTL provides a higher accuracy than our previous state-of-the-art DL method (mean absolute differences improve by 20 K for temperature and 0.2 dex for metallicity from DL to DTL when compared with reference values from interferometry and FGK+M binaries). Furthermore, the machine learning (internal) precision of DTL also improves as uncertainties are five times smaller on average. These results indicate that DTL is a robust tool for obtaining M-dwarf stellar parameters comparable to those obtained from independent estimations for well-known stars.
Published: 2023

2. Two temperate earth-mass planets orbiting the nearby star GJ 1002

Author: Ministerio de Ciencia e Innovación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Consejo Superior de Investigaciones Científicas (España), Fundação para a Ciência e a Tecnologia (Portugal), Junta de Andalucía, Swiss National Science Foundation, Gobierno de Canarias, Suárez Mascareño, A., González-Álvarez, E., Zapatero Osorio, María Rosa, Lillo-Box, Jorge, Faria, J. P., Passegger, V.M., González Hernández, Jonay I., Figueira, Pedro, Sozzetti, Alessandro, Rebolo López, Rafael, Pepe, F., Santos, Nuno C., Cristiani, Stefano, Lovis, Christophe, Silva, André, Ribas, Ignasi, Amado, Pedro J., Caballero, J. A., Quirrenbach, Andreas, Reiners, Ansgar, Zechmeister, Mathias, Adibekyan, Vardan, Alibert, Y., Béjar, Victor J. S., Benatti, S., D'Odorico, Valentina, Damasso, M., Delisle, J. -B., Di Marcantonio, P., Dreizler, S., Ehrenreich, David, Hatzes, Artie P., Hara, N. C., Henning, Thomas, Kaminski, Adriaan, López González, Maria J., Martins, C.J.A.P., Micela, Giusi, Montes, D., Pallé, Enric, Pedraz, S., Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Tal-Or, L., Sousa, S. G., Udry, Stephane, Ministerio de Ciencia e Innovación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Consejo Superior de Investigaciones Científicas (España), Fundação para a Ciência e a Tecnologia (Portugal), Junta de Andalucía, Swiss National Science Foundation, Gobierno de Canarias, Suárez Mascareño, A., González-Álvarez, E., Zapatero Osorio, María Rosa, Lillo-Box, Jorge, Faria, J. P., Passegger, V.M., González Hernández, Jonay I., Figueira, Pedro, Sozzetti, Alessandro, Rebolo López, Rafael, Pepe, F., Santos, Nuno C., Cristiani, Stefano, Lovis, Christophe, Silva, André, Ribas, Ignasi, Amado, Pedro J., Caballero, J. A., Quirrenbach, Andreas, Reiners, Ansgar, Zechmeister, Mathias, Adibekyan, Vardan, Alibert, Y., Béjar, Victor J. S., Benatti, S., D'Odorico, Valentina, Damasso, M., Delisle, J. -B., Di Marcantonio, P., Dreizler, S., Ehrenreich, David, Hatzes, Artie P., Hara, N. C., Henning, Thomas, Kaminski, Adriaan, López González, Maria J., Martins, C.J.A.P., Micela, Giusi, Montes, D., Pallé, Enric, Pedraz, S., Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Tal-Or, L., Sousa, S. G., and Udry, Stephane
Abstract: We report the discovery and characterisation of two Earth-mass planets orbiting in the habitable zone of the nearby M-dwarf GJ 1002 based on the analysis of the radial-velocity (RV) time series from the ESPRESSO and CARMENES spectrographs. The host star is the quiet M5.5 V star GJ 1002 (relatively faint in the optical, V ~ 13.8 mag, but brighter in the infrared, J ~ 8.3 mag), located at 4.84 pc from the Sun. We analyse 139 spectroscopic observations taken between 2017 and 2021. We performed a joint analysis of the time series of the RV and full-width half maximum (FWHM) of the cross-correlation function (CCF) to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with the stellar activity. We detect the signal of two planets orbiting GJ 1002. GJ 1002 b is a planet with a minimum mass mp sin i of 1.08 ± 0.13 M⊕ with an orbital period of 10.3465 ± 0.0027 days at a distance of 0.0457 ± 0.0013 au from its parent star, receiving an estimated stellar flux of 0.67 F⊕. GJ 1002 c is a planet with a minimum mass mp sin i of 1.36 ± 0.17 M⊕ with an orbital period of 20.202 ± 0.013 days at a distance of 0.0738 ± 0.0021 au from its parent star, receiving an estimated stellar flux of 0.257 F⊕. We also detect the rotation signature of the star, with a period of 126 ± 15 days. We find that there is a correlation between the temperature of certain optical elements in the spectrographs and changes in the instrumental profile that can affect the scientific data, showing a seasonal behaviour that creates spurious signals at periods longer than ~200 days. GJ 1002 is one of the few known nearby systems with planets that could potentially host habitable environments. The closeness of the host star to the Sun makes the angular sizes of the orbits of both planets (~9.7 mas and ~15.7 mas, respectively) large enough for their atmosphere to be studied via high-contrast high-resolution spectroscopy with instruments such as the future spectrog
Published: 2023

3. Precise mass determination for the keystone sub-Neptune planet transiting the mid-type M dwarf G 9-40

Author: Ministerio de Ciencia e Innovación (España), European Commission, Luque, Alejandro, Nowak, G., Hirano, T., Kossakowski, D., Pallé, Enric, Nixon, M. C., Morello, G., Amado, Pedro J., Albrecht, S., Caballero, J. A., Cifuentes, C., Cochran, W.D., Deeg, H. J., Dreizler, S., Esparza-Borges, E., Fukui, A., Gandolfi, D., Goffo, E., Guenther, E. W., Hatzes, Artie P., Henning, Thomas, Kabath, P., Kawauchi, K., Korth, J., Kotani, T., Kudo, T., Kuzuhara, M., Lafarga, M., Lam, K. W. F., Livingston, J., Morales, Juan Carlos, Muresan, A., Murgas, F., Narita, N., Osborne, H. L. M., Parviainen, H., Passegger, V.M., Persson, C.M., Quirrenbach, Andreas, Redfield, S., Reffert, S., Reiners, Ansgar, Ribas, Ignasi, Serrano, L. M., Tamura, M., Van Eylen, V., Watanabe, N., Zapatero Osorio, María Rosa, Ministerio de Ciencia e Innovación (España), European Commission, Luque, Alejandro, Nowak, G., Hirano, T., Kossakowski, D., Pallé, Enric, Nixon, M. C., Morello, G., Amado, Pedro J., Albrecht, S., Caballero, J. A., Cifuentes, C., Cochran, W.D., Deeg, H. J., Dreizler, S., Esparza-Borges, E., Fukui, A., Gandolfi, D., Goffo, E., Guenther, E. W., Hatzes, Artie P., Henning, Thomas, Kabath, P., Kawauchi, K., Korth, J., Kotani, T., Kudo, T., Kuzuhara, M., Lafarga, M., Lam, K. W. F., Livingston, J., Morales, Juan Carlos, Muresan, A., Murgas, F., Narita, N., Osborne, H. L. M., Parviainen, H., Passegger, V.M., Persson, C.M., Quirrenbach, Andreas, Redfield, S., Reffert, S., Reiners, Ansgar, Ribas, Ignasi, Serrano, L. M., Tamura, M., Van Eylen, V., Watanabe, N., and Zapatero Osorio, María Rosa
Abstract: Context. Despite being a prominent subset of the exoplanet population discovered in the past three decades, the nature and provenance of sub-Neptune-sized planets is still one of the open questions in exoplanet science. Aims. For planets orbiting bright stars, precisely measuring the orbital and planet parameters of the system is the best approach to distinguish between competing theories regarding their formation and evolution. Methods. We obtained 69 new radial velocity observations of the mid-M dwarf G 9–40 with the CARMENES instrument to measure for the first time the mass of its transiting sub-Neptune planet, G 9–40 b, discovered in data from the K2 mission. Results. Combined with new observations from the TESS mission during Sectors 44, 45, and 46, we are able to measure the radius of the planet to an uncertainty of 3.4% (Rb = 1.900 ± 0.065 R⊕) and determine its mass with a precision of 16% (Mb = 4.00 ± 0.63 M⊕). The resulting bulk density of the planet is inconsistent with a terrestrial composition and suggests the presence of either a water-rich core or a significant hydrogen-rich envelope. Conclusions. G 9–40 b is referred to as a keystone planet due to its location in period-radius space within the radius valley. Several theories offer explanations for the origin and properties of this population and this planet is a valuable target for testing the dependence of those models on stellar host mass. By virtue of its brightness and small size of the host, it joins L 98-59 d as one of the two best warm (Teq ~ 400 K) sub-Neptunes for atmospheric characterization with JWST, which will probe cloud formation in sub-Neptune-sized planets and break the degeneracies of internal composition models. © R. Luque et al. 2022.
Published: 2022

4. A multi-planetary system orbiting the early-M dwarf TOI-1238

Author: European Commission, Ministerio de Ciencia e Innovación (España), National Aeronautics and Space Administration (US), González-Álvarez, E., Zapatero Osorio, María Rosa, Sanz-Forcada, J., Caballero, J. A., Reffert, S., Béjar, Victor J. S., Hatzes, Artie P., Herrero, E., Jeffers, Sandra V., Kemmer, J., López González, Maria J., Luque, R., Molaverdikhani, K., Morello, G., Nagel, Evangelos, Quirrenbach, Andreas, Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Schlecker, M., Schweitzer, Andreas, Stock, S., Passegger, V.M., Trifonov, T., Amado, Pedro J., Baker, D., Boyd, P. T., Cadieux, Charles, Charbonneau, David, Collins, Karen A., Doyon, R., Dreizler, S., Espinoza, Néstor, Fűrész, G., Furlan, E., Hesse, K., Howell, S.B., Jenkins, Jon M., Kidwell, R. C., Latham, David W., McLeod, K. K., Montes, D., Morales, Juan Carlos, O'Dwyer, T., Pallé, Enric, Pedraz, S., Reiners, Ansgar, Ribas, Ignasi, Quinn, S. N., Schnaible, C., Seager, S., Skinner, B., Smith, J. C., Schwarz, R. P., Shporer, A., Vanderspek, R., Winn, J. N., European Commission, Ministerio de Ciencia e Innovación (España), National Aeronautics and Space Administration (US), González-Álvarez, E., Zapatero Osorio, María Rosa, Sanz-Forcada, J., Caballero, J. A., Reffert, S., Béjar, Victor J. S., Hatzes, Artie P., Herrero, E., Jeffers, Sandra V., Kemmer, J., López González, Maria J., Luque, R., Molaverdikhani, K., Morello, G., Nagel, Evangelos, Quirrenbach, Andreas, Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Schlecker, M., Schweitzer, Andreas, Stock, S., Passegger, V.M., Trifonov, T., Amado, Pedro J., Baker, D., Boyd, P. T., Cadieux, Charles, Charbonneau, David, Collins, Karen A., Doyon, R., Dreizler, S., Espinoza, Néstor, Fűrész, G., Furlan, E., Hesse, K., Howell, S.B., Jenkins, Jon M., Kidwell, R. C., Latham, David W., McLeod, K. K., Montes, D., Morales, Juan Carlos, O'Dwyer, T., Pallé, Enric, Pedraz, S., Reiners, Ansgar, Ribas, Ignasi, Quinn, S. N., Schnaible, C., Seager, S., Skinner, B., Smith, J. C., Schwarz, R. P., Shporer, A., Vanderspek, R., and Winn, J. N.
Abstract: Context. The number of super-Earth and Earth-mass planet discoveries has increased significantly in the last two decades thanks to the Doppler radial velocity and planetary transit observing techniques. Either technique can detect planet candidates on its own, but the power of a combined photometric and spectroscopic analysis is unique for an insightful characterization of the planets, which in turn has repercussions for our understanding of the architecture of planetary systems and, therefore, their formation and evolution. Aims. Two transiting planet candidates with super-Earth radii around the nearby (d = 70.64 ± 0.06 pc) K7–M0 dwarf star TOI-1238 were announced by NASA’s Transiting Exoplanet Survey Satellite (TESS), which observed the field of TOI-1238 in four different sectors. We aim to validate their planetary nature using precise radial velocities taken with the CARMENES spectrograph. Methods. We obtained 55 CARMENES radial velocity measurements that span the 11 months between 9 May 2020 and 5 April 2021. For a better characterization of the parent star’s activity, we also collected contemporaneous optical photometric observations at the Joan Oró and Sierra Nevada observatories and retrieved archival photometry from the literature. We performed a combined TESS+CARMENES photometric and spectroscopic analysis by including Gaussian processes and Keplerian orbits to account for the stellar activity and planetary signals simultaneously. Results. We estimate that TOI-1238 has a rotation period of 40 ± 5 d based on photometric and spectroscopic data. The combined analysis confirms the discovery of two transiting planets, TOI-1238 b and c, with orbital periods of 0.764597−0.000011+0.000013 d and 3.294736−0.000036+0.000034 d, masses of 3.76−1.07+1.15 M⊕ and 8.32−1.88+1.90 M⊕, and radii of 1.21−0.10+0.11 R⊕ and 2.11−0.14+0.14 R⊕. They orbit their parent star at semimajor axes of 0.0137 ± 0.0004 au and 0.036 ± 0.001 au, respectively.The two planets are placed on opposi
Published: 2022

5. Metallicities in M dwarfs: Investigating different determination techniques

Author: National Aeronautics and Space Administration (US), European Commission, Ministerio de Ciencia e Innovación (España), Passegger, V.M., Bello-García, A., Ordieres-Meré, J., Antoniadis-Karnavas, A., Marfil, E., Duque-Arribas, C., Amado, Pedro J., Delgado-Mena, E., Montes, D., Rojas-Ayala, B., Schweitzer, Andreas, Tabernero, H. M., Béjar, Victor J. S., Caballero, J. A., Hatzes, Artie P., Henning, Thomas, Pedraz, S., Quirrenbach, Andreas, Reiners, Ansgar, Ribas, Ignasi, National Aeronautics and Space Administration (US), European Commission, Ministerio de Ciencia e Innovación (España), Passegger, V.M., Bello-García, A., Ordieres-Meré, J., Antoniadis-Karnavas, A., Marfil, E., Duque-Arribas, C., Amado, Pedro J., Delgado-Mena, E., Montes, D., Rojas-Ayala, B., Schweitzer, Andreas, Tabernero, H. M., Béjar, Victor J. S., Caballero, J. A., Hatzes, Artie P., Henning, Thomas, Pedraz, S., Quirrenbach, Andreas, Reiners, Ansgar, and Ribas, Ignasi
Abstract: Deriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been developed in recent years to determine accurate stellar parameters for these cool stars (Teff ≲ 4000 K). However, significant differences can be found at times when comparing metallicities for the same star derived using different methods. In this work, we determine the effective temperatures, surface gravities, and metallicities of 18 well-studied M dwarfs observed with the CARMENES high-resolution spectrograph following different approaches, including synthetic spectral fitting, analysis of pseudo-equivalent widths, and machine learning. We analyzed the discrepancies in the derived stellar parameters, including metallicity, in several analysis runs. Our goal is to minimize these discrepancies and find stellar parameters that are more consistent with the literature values. We attempted to achieve this consistency by standardizing the most commonly used components, such as wavelength ranges, synthetic model spectra, continuum normalization methods, and stellar parameters. We conclude that although such modifications work quite well for hotter main-sequence stars, they do not improve the consistency in stellar parameters for M dwarfs, leading to mean deviations of around 50–200 K in temperature and 0.1–0.3 dex in metallicity. In particular, M dwarfs are much more complex and a standardization of the aforementioned components cannot be considered as a straightforward recipe for bringing consistency to the derived parameters. Further in-depth investigations of the employed methods would be necessary in order to identify and correct for the discrepancies that remain. © ESO 2022.
Published: 2022

6. The CARMENES search for exoplanets around M dwarfs: Two Saturn-mass planets orbiting active stars

Author: Ministerio de Ciencia e Innovación (España), European Commission, National Aeronautics and Space Administration (US), Quirrenbach, Andreas, Passegger, V.M., Trifonov, T., Amado, Pedro J., Caballero, J. A., Reiners, Ansgar, Ribas, Ignasi, Aceituno, Jesús, Béjar, Victor J. S., Chaturvedi, P., González-Cuesta, L., Henning, Thomas, Herrero, E., Kaminski, A., Kürster, M., Lalitha, S., Lodieu, N., López González, Maria J., Montes, D., Pallé, Enric, Perger, M., Pollacco, D., Reffert, S., Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Shan, Y., Tal-Or, L., Zapatero Osorio, María Rosa, Zechmeister, Mathias, Ministerio de Ciencia e Innovación (España), European Commission, National Aeronautics and Space Administration (US), Quirrenbach, Andreas, Passegger, V.M., Trifonov, T., Amado, Pedro J., Caballero, J. A., Reiners, Ansgar, Ribas, Ignasi, Aceituno, Jesús, Béjar, Victor J. S., Chaturvedi, P., González-Cuesta, L., Henning, Thomas, Herrero, E., Kaminski, A., Kürster, M., Lalitha, S., Lodieu, N., López González, Maria J., Montes, D., Pallé, Enric, Perger, M., Pollacco, D., Reffert, S., Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Shan, Y., Tal-Or, L., Zapatero Osorio, María Rosa, and Zechmeister, Mathias
Abstract: The CARMENES radial-velocity survey is currently searching for planets in a sample of 387 M dwarfs. Here we report on two Saturn-mass planets orbiting TYC 2187-512-1 (M* = 0.50 M⊙) and TZ Ari (M* = 0.15 M⊙), respectively. We obtained supplementary photometric time series, which we use along with spectroscopic information to determine the rotation periods of the two stars. In both cases, the radial velocities also show strong modulations at the respective rotation period. We thus modeled the radial velocities as a Keplerian orbit plus a Gaussian process representing the stellar variability. TYC 2187-512-1 is found to harbor a planet with a minimum mass of 0.33 MJup in a near-circular 692-day orbit. The companion of TZ Ari has a minimum mass of 0.21 MJup, orbital period of 771 d, and orbital eccentricity of 0.46. We provide an overview of all known giant planets in the CARMENES sample, from which we infer an occurrence rate of giant planets orbiting M dwarfs with periods up to 2 yr in the range between 2 and 6%. TZ Ari b is only the second giant planet discovered orbiting a host with mass less than 0.3 M⊙. These objects occupy an extreme location in the planet mass versus host mass plane. It is difficult to explain their formation in core-accretion scenarios, so they may possibly have been formed through a disk fragmentation process. © ESO 2022.
Published: 2022

7. Precise mass determination for the keystone sub-Neptune planet transiting the mid-type M dwarf G 9-40

Author: Luque, R., Nowak, G., Hirano, T., Kossakowski, D., Palle, E., Nixon, M.C., Morello, G., Amado, P. J., Albrecht, S., Caballero, J. A., Cifuentes, C., Cochran, W. D., Deeg, H. J., Dreizler, S., Esparza-Borges, E., Fukui, Akihiko, Gandolfi, D., Goffo, E., Guenther, E. W., Hatzes, A. P., Henning, T., Kabáth, P., Kawauchi, K., Korth, J., Kotani, T., Kudo, T., Kuzuhara, M., Lafarga, M., Lam, K. W. F., Livingston, J., Morales, J. C., Muresan, A., Murgas, F., Narita, N., Osborne, H. L. M., Parviainen, H., Passegger, V.M., Persson, C. M., Quirrenbach, A., Redfield, S., Reffert, S., Reiners, A., Ribas, I., Serrano, L. M., Tamura, M., Van Eylen, V., Watanabe, N., Zapatero Osorio, M. R., Ministerio de Ciencia e Innovación (España), and European Commission
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), techniques: photometric, Space and Planetary Science, stars: low-mass, techniques: radial velocities, stars: individual: G 9-40, FOS: Physical sciences, Astronomy and Astrophysics, Stars: individual: G 9–40, planetary systems, Astrophysics - Earth and Planetary Astrophysics
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., Context. Despite being a prominent subset of the exoplanet population discovered in the past three decades, the nature and provenance of sub-Neptune-sized planets is still one of the open questions in exoplanet science. Aims. For planets orbiting bright stars, precisely measuring the orbital and planet parameters of the system is the best approach to distinguish between competing theories regarding their formation and evolution. Methods. We obtained 69 new radial velocity observations of the mid-M dwarf G 9–40 with the CARMENES instrument to measure for the first time the mass of its transiting sub-Neptune planet, G 9–40 b, discovered in data from the K2 mission. Results. Combined with new observations from the TESS mission during Sectors 44, 45, and 46, we are able to measure the radius of the planet to an uncertainty of 3.4% (Rb = 1.900 ± 0.065 R⊕) and determine its mass with a precision of 16% (Mb = 4.00 ± 0.63 M⊕). The resulting bulk density of the planet is inconsistent with a terrestrial composition and suggests the presence of either a water-rich core or a significant hydrogen-rich envelope. Conclusions. G 9–40 b is referred to as a keystone planet due to its location in period-radius space within the radius valley. Several theories offer explanations for the origin and properties of this population and this planet is a valuable target for testing the dependence of those models on stellar host mass. By virtue of its brightness and small size of the host, it joins L 98-59 d as one of the two best warm (Teq ~ 400 K) sub-Neptunes for atmospheric characterization with JWST, which will probe cloud formation in sub-Neptune-sized planets and break the degeneracies of internal composition models. © R. Luque et al. 2022., This work was supported by the KESPRINT (www.kesprint.science.) collaboration, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions. This paper includes data collected by the Kepler and TESS missions, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This article is partly based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. CARMENES is an instrument at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto (Almeria, Spain), operated jointly by the Junta de Andalucía and the Instituto de Astrofísica de Andalucía (CSIC). CARMENES was funded by the Max-Planck-Gesellschaft (MPG), the Consejo Superior de Investigaciones Científicas (CSIC), the Ministerio de Economia y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through projects FICTS-2011-02, ICTS-2017-07-CAHA-4, and CAHA16-CE-3978, and the members of the CARMENES Consortium with additional contributions. IRD is operated by the Astrobiology Center of the National Institute of Natural Sciences of Japan. R.L. acknowledges funding from University of La Laguna through the Margarita Salas Fellowship from the Spanish Ministry of Universities ref. UNI/551/2021-May 26 under the EU Next Generation funds and from the Spanish Ministerio de Ciencia e Innovación, through project PID2019-109522GB-C52, and the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This work is partly supported by JSPS KAKENHI Grant Numbers 18H05442, 15H02063, 22000005, JP18H05439, JP21K20376 and JST CREST Grant Number JPMJCR1761. C.C. acknowledges financial support from the ERDF through project AYA2016-79425-C3-1/2/3-P. C.M.P. acknowledges the support of the Swedish National Space Agency (DNR 65/19). H.J.D. acknowledges support from the Spanish Research Agency of the Ministry of Science and Innovation (AEI-MICINN) under grant PID2019-107061GB-C66. P.K. acknowledges the support from the grant LTT-20015. K.W.F.L. was supported by Deutsche Forschungsgemeinschaft grants RA714/14-1 within the DFG Schwerpunkt SPP 1992, Exploring the Diversity of Extrasolar Planets. This work was supported by the DFG Research Unit FOR2544 “Blue Planets around Red Stars” G.M. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 895525.
Published: 2022
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8. The CARMENES search for exoplanets around M dwarfs. Not-so-fine hyperfine-split vanadium lines in cool star spectra

Author: European Commission, Austrian Science Fund, National Aeronautics and Space Administration (US), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Shan, Y., Reiners, Ansgar, Fabbian, D., Marfil, E., Montes, D., Tabernero, H. M., Ribas, Ignasi, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Jesús, Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, A., Kürster, M., Lafarga, M., Morales, Juan Carlos, Nagel, Evangelos, Pallé, Enric, Passegger, V.M., Rodríguez-López, Cristina, Schweitzer, Andreas, Zechmeister, Mathias, European Commission, Austrian Science Fund, National Aeronautics and Space Administration (US), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Shan, Y., Reiners, Ansgar, Fabbian, D., Marfil, E., Montes, D., Tabernero, H. M., Ribas, Ignasi, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Jesús, Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, A., Kürster, M., Lafarga, M., Morales, Juan Carlos, Nagel, Evangelos, Pallé, Enric, Passegger, V.M., Rodríguez-López, Cristina, Schweitzer, Andreas, and Zechmeister, Mathias
Abstract: Context. M-dwarf spectra are complex and notoriously difficult to model, posing challenges to understanding their photospheric properties and compositions in depth. Vanadium (V) is an iron-group element whose abundance supposedly closely tracks that of iron, but has origins that are not completely understood. Aims. Our aim is to characterize a series of neutral vanadium atomic absorption lines in the 800-910 nm wavelength region of high signal-to-noise, high-resolution, telluric-corrected M-dwarf spectra from the CARMENES survey. Many of these lines are prominent and exhibit a distinctive broad and flat-bottom shape, which is a result of hyperfine structure (HFS). We investigate the potential and implications of these HFS split lines for abundance analysis of cool stars. Methods. With standard spectral synthesis routines, as provided by the spectroscopy software iSpec and the latest atomic data (including HFS) available from the VALD3 database, we modeled these striking line profiles. We used them to measure V abundances of cool dwarfs. Results. We determined V abundances for 135 early M dwarfs (M0.0 V to M3.5 V) in the CARMENES guaranteed time observations sample. They exhibit a [V/Fe]-[Fe/H] trend consistent with that derived from nearby FG dwarfs. The tight (±0.1 dex) correlation between [V/H] and [Fe/H] suggests the potential application of V as an alternative metallicity indicator in M dwarfs. We also show hints that neglecting to model HFS could partially explain the temperature correlation in V abundance measurements observed in previous studies of samples involving dwarf stars with Teff 5300 K. Conclusions. Our work suggests that HFS can impact certain absorption lines in cool photospheres more severely than in Sun-like ones. Therefore, we advocate that HFS should be carefully treated in abundance studies in stars cooler than ∼5000 K. On the other hand, strong HFS split lines in high-resolution spectra present an opportunity for precision chemical analyses o
Published: 2021

9. The CARMENES search for exoplanets around M dwarfs: Planet occurrence rates from a subsample of 71 stars

Author: German Research Foundation, European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, National Aeronautics and Space Administration (US), Sabotta, S., Schlecker, M., Chaturvedi, P., Guenther, E. W., Muñoz Rodríguez, I., Muñoz Sánchez, J. C., Caballero, J. A., Shan, Y., Reffert, S., Ribas, Ignasi, Reiners, Ansgar, Hatzes, Artie P., Amado, Pedro J., Klahr, H., Morales, Juan Carlos, Quirrenbach, Andreas, Henning, Thomas, Dreizler, S., Pallé, Enric, Perger, M., Azzaro, M., Jeffers, Sandra V., Kaminski, A., Kürster, M., Lafarga, M., Montes, D., Passegger, V.M., Zechmeister, Mathias, German Research Foundation, European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, National Aeronautics and Space Administration (US), Sabotta, S., Schlecker, M., Chaturvedi, P., Guenther, E. W., Muñoz Rodríguez, I., Muñoz Sánchez, J. C., Caballero, J. A., Shan, Y., Reffert, S., Ribas, Ignasi, Reiners, Ansgar, Hatzes, Artie P., Amado, Pedro J., Klahr, H., Morales, Juan Carlos, Quirrenbach, Andreas, Henning, Thomas, Dreizler, S., Pallé, Enric, Perger, M., Azzaro, M., Jeffers, Sandra V., Kaminski, A., Kürster, M., Lafarga, M., Montes, D., Passegger, V.M., and Zechmeister, Mathias
Abstract: Context. The CARMENES exoplanet survey of M dwarfs has obtained more than 18 000 spectra of 329 nearby M dwarfs over the past five years as part of its guaranteed time observations (GTO) program. Aims. We determine planet occurrence rates with the 71 stars from the GTO program for which we have more than 50 observations. Methods. We use injection-and-retrieval experiments on the radial-velocity time series to measure detection probabilities. We include 27 planets in 21 planetary systems in our analysis. Results. We find 0.06-0.03+0.04 giant planets (100 Mpdbl < Mpl sin i < 1000 Mpdbl) per star in periods of up to 1000 d, but due to a selection bias this number could be up to a factor of five lower in the whole 329-star sample. The upper limit for hot Jupiters (orbital period of less than 10 d) is 0.03 planets per star, while the occurrence rate of planets with intermediate masses (10 Mpdbl < Mpl sin i < 100 Mpdbl) is 0.18-0.05+0.07 planets per star. Less massive planets with 1 Mpdbl < Mpl sin i < 10 Mpdbl are very abundant, with an estimated rate of 1.32-0.31+0.33 planets per star for periods of up to 100 d. When considering only late M dwarfs with masses M- < 0.34 M⊙ , planets more massive than 10 Mpdbl become rare. Instead, low-mass planets with periods shorter than 10 d are significantly overabundant. Conclusions. For orbital periods shorter than 100 d, our results confirm the known stellar mass dependences from the Kepler survey: M dwarfs host fewer giant planets and at least two times more planets with Mpl sin i < 10 Mpdbl than G-type stars. In contrast to previous results, planets around our sample of very low-mass stars have a higher occurrence rate in short-period orbits of less than 10 d. Our results demonstrate the need to take into account host star masses in planet formation models. © ESO 2021.
Published: 2021

10. The CARMENES search for exoplanets around M dwarfs: Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780

Author: Parviainen, H., Molaverdikhani, K., Jeffers, S.V., Diéz Alonso, E., Trifonov, T., Rodríguez-López, C., Caballero, J.A., Schlecker, M., Esparza-Borges, E., Montes, D., Lodieu, N., Nagel, E., Massey, B., Vanderspek, R., Stangret, M., Tanner, A., Guerra, P., Cale, B., Zapatero Osorio, M.R., Reiners, A., Rose, M.E., Kotani, T., Wittrock, J., Mann, A.W., Matthews, E., Latham, D.W., Barkaoui, K., Ribas, I., Gillon, M., Morales, J.C., Nowak, G., Pedraz, S., Reffert, S., Quirrenbach, A., Herrero, E., Collins, K.I., Ricker, G.R., Tamura, M., Béjar, V.J.S., Lillo-Box, J., Jenkins, J.M., Teske, J., Kemmer, J., Hirano, T., Lissauer, J.J., Plavchan, P., Schlieder, J.E., Kossakowski, D., Stock, S., El Mufti, M., Montañés-Rodríguez, P., Mori, M., Gaidos, E., De León, J.P., Benkhaldoun, Z., Oshagh, M., Schweitzer, A., Kürster, M., Narita, N., Casasayas Barris, N., Seager, S., Howell, S.B., Gonzales, E.J., Jehin, E., Kielkopf, J.F., Dreizler, S., Zechmeister, M., Hidalgo, D., Chaturvedi, P., Madrigal-Aguado, A., Matson, R.A., Lafarga, M., Amado, P.J., Essack, Z., Bauer, F.F., Kaminski, A., Law, N., Henning, T., Pollacco, D., Collins, K.A., Zohrabi, F., Cortés-Contreras, M., Pallé, E., Espinoza, N., Hesse, K., Murgas, F., Aceituno, F.J., Pozuelos, F.J., Crossfield, I.J.M., Barrado, D., Watanabe, D., Ziegler, C., Fukui, A., Hatzes, A., Twicken, J.D., Passegger, V.M., Cifuentes, C., Caldwell, D.A., Chen, G., and Luque, R.
Abstract: We present the discovery and characterisation of two transiting planets observed by the Transiting Exoplanet Survey Satellite (TESS) orbiting the nearby (d∗ ≈ 22 pc), bright (J ≈ 9 mag) M3.5 dwarf LTT 3780 (TOI-732). We confirm both planets and their association with LTT 3780 via ground-based photometry and determine their masses using precise radial velocities measured with the CARMENES spectrograph. Precise stellar parameters determined from CARMENES high-resolution spectra confirm that LTT 3780 is a mid-M dwarf with an effective temperature of Teff = 3360 ± 51 K, a surface gravity of log g∗ = 4.81 ± 0.04 (cgs), and an iron abundance of [Fe/H] = 0.09 ± 0.16 dex, with an inferred mass of M∗ = 0.379 ± 0.016M· and a radius of R∗ = 0.382 ± 0.012R·. The ultra-short-period planet LTT 3780 b (Pb = 0.77 d) with a radius of 1.35-0.06+0.06 R·, a mass of 2.34-0.23+0.24 M·, and a bulk density of 5.24-0.81+0.94 g cm-3 joins the population of Earth-size planets with rocky, terrestrial composition. The outer planet, LTT 3780 c, with an orbital period of 12.25 d, radius of 2.42-0.10+0.10 R·, mass of 6.29-0.61+0.63 M·, and mean density of 2.45-0.37+0.44 g cm-3 belongs to the population of dense sub-Neptunes. With the two planets located on opposite sides of the radius gap, this planetary system is anexcellent target for testing planetary formation, evolution, and atmospheric models. In particular, LTT 3780 c is an ideal object for atmospheric studies with the James Webb Space Telescope (JWST).
Published: 2020
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11. CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions

Author: Cifuentes, C., Caballero, J.A., Cortés Contreras, Miriam, Montes Gutiérrez, David, Abellán, F.J., Dorda, R., Holgado, G., Zapatero Osorio, M.R., Morales, J.C., Amado, P.J., Passegger, V.M., Quirrenbach, A., Reiners, A., Ribas, I., Schweitzer, A., Sanz Forcada, J., Seifert, W., Solano, E., Cifuentes, C., Caballero, J.A., Cortés Contreras, Miriam, Montes Gutiérrez, David, Abellán, F.J., Dorda, R., Holgado, G., Zapatero Osorio, M.R., Morales, J.C., Amado, P.J., Passegger, V.M., Quirrenbach, A., Reiners, A., Ribas, I., Schweitzer, A., Sanz Forcada, J., Seifert, W., and Solano, E.
Abstract: © 2020 ESO. We thank the anonymous referee for the comments that helped to improve the quality of this paper, and also E. E. Mamajek and E. Gaidos for their valuable insights and suggestions. CARMENES is an instrument for the Centro Astronómico Hispano-Alemán de Calar Alto (CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Insitut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía. This work was partly financed by the Spanish Ministry of Science and Innovation through grants AYA2016-79425- C3-1/2/3-P and BES-2017-080769, and by NASA through grant NNX17AG24G. C.C., F.J.A.P., R.D., and G.H. compiled data for this work during their MSc theses at the Universidad Complutense de Madrid. This publication made use of VOSA and the Filter Profile Service, developed and maintained by the Spanish Virtual Observatory through grant AYA2017-84089, the SIMBAD database, the Aladin sky atlas, and the VizieR catalogue access tool developed at CDS, Strasbourg Observatory, France, and the Python libraries Matplotlib, NumPy, SciPy and collection of software packages AstroPy., Ministerio de Ciencia e Innovación (MICINN)/FEDER, CARMENES (German Max-PlanckGesellschaft (MPG); Consejo Superior de Investigaciones Científicas (CSIC); FEDER/ERF FICTS-2011-02; CARMENES Consortium)), NASA, German Max-Planck-Gesellschaft (MPG), Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Insitut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán, German Science Foundation through the Major Research Instrumentation Programme, DFG Research Unit FOR2544 “Blue Planets around Red Stars”, Klaus Tschira Stiftung, Junta de Andalucía, states of Baden-Württemberg and Niedersachsen, Spanish Virtual Observatory, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub
Published: 2020

12. The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars

Author: Abia, C., Tabernero, H.M., Korotin, S. A., Montes, D., Marfil, E., Caballero, J. A., Straniero, O., Prantzos, N., Ribas, Ignasi, Reiners, A., Quirrenbach, A., Amado, Pedro J., Béjar, V.J.S., Cortés-Contreras, M., Dreizler, S., Henning, T., Jeffers, S. V., Kaminski, Adrian, Kürster, M., Lafarga, M., López-Gallifa, Á., Morales, J. C., Nagel, E., Passegger, V.M., Pedraz, S., Rodríguez-López, Cristina, Schweitzer, A., Zechmeister, M., Abia, C., Tabernero, H.M., Korotin, S. A., Montes, D., Marfil, E., Caballero, J. A., Straniero, O., Prantzos, N., Ribas, Ignasi, Reiners, A., Quirrenbach, A., Amado, Pedro J., Béjar, V.J.S., Cortés-Contreras, M., Dreizler, S., Henning, T., Jeffers, S. V., Kaminski, Adrian, Kürster, M., Lafarga, M., López-Gallifa, Á., Morales, J. C., Nagel, E., Passegger, V.M., Pedraz, S., Rodríguez-López, Cristina, Schweitzer, A., and Zechmeister, M.
Abstract: Due to their ubiquity and very long main-sequence lifetimes, abundance determinations in M dwarfs provide a powerful and alternative tool to GK dwarfs to study the formation and chemical enrichment history of our Galaxy. In this study, abundances of the neutron-capture elements Rb, Sr, and Zr are derived, for the first time, in a sample of nearby M dwarfs. We focus on stars in the metallicity range-0.5 â‰² [Fe/H] â‰² +0.3, an interval poorly explored for Rb abundances in previous analyses. To do this we use high-resolution, high-signal-to-noise-ratio, optical and near-infrared spectra of 57 M dwarfs observed with CARMENES. The resulting [Sr/Fe] and [Zr/Fe] ratios for most M dwarfs are almost constant at about the solar value, and are identical to those found in GK dwarfs of the same metallicity. However, for Rb we find systematic underabundances ([Rb/Fe] < 0.0) by a factor two on average. Furthermore, a tendency is found for Rb-but not for other heavy elements (Sr, Zr)-to increase with increasing metallicity such that [Rb/Fe] â‰³ 0.0 is attained at metallicities higher than solar. These are surprising results, never seen for any other heavy element, and are difficult to understand within the formulation of the s-and r-processes, both contributing sources to the Galactic Rb abundance. We discuss the reliability of these findings for Rb in terms of non-LTE (local thermodynamic equilibrium) effects, stellar activity, or an anomalous Rb abundance in the Solar System, but no explanation is found. We then interpret the full observed [Rb/Fe] versus [Fe/H] trend within the framework of theoretical predictions from state-of-the-art chemical evolution models for heavy elements, but a simple interpretation is not found either. In particular, the possible secondary behaviour of the [Rb/Fe] ratio at super-solar metallicities would require a much larger production of Rb than currently predicted in AGB stars through the s-process without overproducing Sr and Zr.
Published: 2020

13. The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities

Author: Baroch, David, Morales, Juan, Ribas, Ignasi, Herrero, E., Rosich, Albert, Perger, M., Anglada-Escudé, Guillem, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Jeffers, Sandra V., Cifuentes, C., Passegger, V.M., Schweitzer, Andreas, Lafarga, M., Bauer, FF, Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Dreizler, S., Galadí-Enriquez, D., Hatzes, Artie P., Henning, Thomas, Kaminski, Adrian, Kürster, M., Montes, D., Rodríguez-López, Cristina, Zechmeister, Mathias, Baroch, David, Morales, Juan, Ribas, Ignasi, Herrero, E., Rosich, Albert, Perger, M., Anglada-Escudé, Guillem, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Jeffers, Sandra V., Cifuentes, C., Passegger, V.M., Schweitzer, Andreas, Lafarga, M., Bauer, FF, Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Dreizler, S., Galadí-Enriquez, D., Hatzes, Artie P., Henning, Thomas, Kaminski, Adrian, Kürster, M., Montes, D., Rodríguez-López, Cristina, and Zechmeister, Mathias
Abstract: Context. Variability caused by stellar activity represents a challenge to the discovery and characterization of terrestrial exoplanets and complicates the interpretation of atmospheric planetary signals. Aims. We aim to use a detailed modeling tool to reproduce the effect of active regions on radial velocity measurements, which aids the identification of the key parameters that have an impact on the induced variability. Methods. We analyzed the effect of stellar activity on radial velocities as a function of wavelength by simulating the impact of the properties of spots, shifts induced by convective motions, and rotation. We focused our modeling effort on the active star YZ CMi (GJ 285), which was photometrically and spectroscopically monitored with CARMENES and the Telescopi Joan Oró. Results. We demonstrate that radial velocity curves at different wavelengths yield determinations of key properties of active regions, including spot-filling factor, temperature contrast, and location, thus solving the degeneracy between them. Most notably, our model is also sensitive to convective motions. Results indicate a reduced convective shift for M dwarfs when compared to solar-Type stars (in agreement with theoretical extrapolations) and points to a small global convective redshift instead of blueshift. Conclusions. Using a novel approach based on simultaneous chromatic radial velocities and light curves, we can set strong constraints on stellar activity, including an elusive parameter such as the net convective motion effect.
Published: 2020

14. The CARMENES search for exoplanets around M dwarfs: Three temperate-to-warm super-Earths

Author: Stock, S., Nagel, Evangelos, Kemmer, J., Passegger, V.M., Reffert, S., Quirrenbach, Andreas, Caballero, J. A., Czesla, S., Béjar, Victor J. S., Cardona, C., Díez-Alonso, E., Herrero, E., Lalitha, S., Schlecker, M., Tal-Or, L., Rodríguez, E., Rodríguez-López, Cristina, Ribas, Ignasi, Reiners, Ansgar, Amado, Pedro J., Bauer, FF, Bluhm, P., Cortés-Contreras, M., González-Cuesta, L., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López González, Maria J., Montes, D., Morales, Juan Carlos, Pedraz, S., Schöfer, P., Schweitzer, Andreas, Trifonov, T., Zapatero Osorio, María Rosa, Zechmeister, Mathias, Stock, S., Nagel, Evangelos, Kemmer, J., Passegger, V.M., Reffert, S., Quirrenbach, Andreas, Caballero, J. A., Czesla, S., Béjar, Victor J. S., Cardona, C., Díez-Alonso, E., Herrero, E., Lalitha, S., Schlecker, M., Tal-Or, L., Rodríguez, E., Rodríguez-López, Cristina, Ribas, Ignasi, Reiners, Ansgar, Amado, Pedro J., Bauer, FF, Bluhm, P., Cortés-Contreras, M., González-Cuesta, L., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López González, Maria J., Montes, D., Morales, Juan Carlos, Pedraz, S., Schöfer, P., Schweitzer, Andreas, Trifonov, T., Zapatero Osorio, María Rosa, and Zechmeister, Mathias
Abstract: We announce the discovery of two planets orbiting the M dwarfs GJ 251 (0.360 ± 0.015M-) and HD 238090 (0.578 ± 0.021M-) based on CARMENES radial velocity (RV) data. In addition, we independently confirm with CARMENES data the existence of Lalande 21185 b, a planet that has recently been discovered with the SOPHIE spectrograph. All three planets belong to the class of warm or temperate super-Earths and share similar properties. The orbital periods are 14.24 d, 13.67 d, and 12.95 d and the minimum masses are 4.0 ± 0.4 M-, 6.9 ± 0.9 M-, and 2.7 ± 0.3 M- for GJ 251 b, HD 238090 b, and Lalande 21185 b, respectively. Based on the orbital and stellar properties, we estimate equilibrium temperatures of 351.0 ± 1.4 K for GJ 251 b, 469.6 ± 2.6 K for HD 238090 b, and 370.1 ± 6.8 K for Lalande 21185 b. For the latter we resolve the daily aliases that were present in the SOPHIE data and that hindered an unambiguous determination of the orbital period. We find no significant signals in any of our spectral activity indicators at the planetary periods. The RV observations were accompanied by contemporaneous photometric observations. We derive stellar rotation periods of 122.1 ± 2.2 d and 96.7 ± 3.7 d for GJ 251 and HD 238090, respectively. The RV data of all three stars exhibit significant signals at the rotational period or its first harmonic. For GJ 251 and Lalande 21185, we also find long-period signals around 600 d, and 2900 d, respectively, which we tentatively attribute to long-term magnetic cycles. We apply a Bayesian approach to carefully model the Keplerian signals simultaneously with the stellar activity using Gaussian process regression models and extensively search for additional significant planetary signals hidden behind the stellar activity. Current planet formation theories suggest that the three systems represent a common architecture, consistent with formation following the core accretion paradigm.
Published: 2020

15. The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars

Author: Ministerio de Ciencia e Innovación (España), European Commission, Universidad Complutense de Madrid, Fundação para a Ciência e a Tecnologia (Portugal), National Aeronautics and Space Administration (US), Abia, C., Tabernero, H. M., Korotin, S. A., Montes, D., Marfil, E., Caballero, J. A., Straniero, O., Prantzos, N., Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López-Gallifa, Á., Morales, Juan Carlos, Nagel, Evangelos, Passegger, V.M., Pedraz, S., Rodríguez-López, Cristina, Schweitzer, Andreas, Zechmeister, Mathias, Ministerio de Ciencia e Innovación (España), European Commission, Universidad Complutense de Madrid, Fundação para a Ciência e a Tecnologia (Portugal), National Aeronautics and Space Administration (US), Abia, C., Tabernero, H. M., Korotin, S. A., Montes, D., Marfil, E., Caballero, J. A., Straniero, O., Prantzos, N., Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López-Gallifa, Á., Morales, Juan Carlos, Nagel, Evangelos, Passegger, V.M., Pedraz, S., Rodríguez-López, Cristina, Schweitzer, Andreas, and Zechmeister, Mathias
Abstract: Due to their ubiquity and very long main-sequence lifetimes, abundance determinations in M dwarfs provide a powerful and alternative tool to GK dwarfs to study the formation and chemical enrichment history of our Galaxy. In this study, abundances of the neutron-capture elements Rb, Sr, and Zr are derived, for the first time, in a sample of nearby M dwarfs. We focus on stars in the metallicity range-0.5 â‰² [Fe/H] â‰² +0.3, an interval poorly explored for Rb abundances in previous analyses. To do this we use high-resolution, high-signal-to-noise-ratio, optical and near-infrared spectra of 57 M dwarfs observed with CARMENES. The resulting [Sr/Fe] and [Zr/Fe] ratios for most M dwarfs are almost constant at about the solar value, and are identical to those found in GK dwarfs of the same metallicity. However, for Rb we find systematic underabundances ([Rb/Fe] < 0.0) by a factor two on average. Furthermore, a tendency is found for Rb-but not for other heavy elements (Sr, Zr)-to increase with increasing metallicity such that [Rb/Fe] â‰³ 0.0 is attained at metallicities higher than solar. These are surprising results, never seen for any other heavy element, and are difficult to understand within the formulation of the s-and r-processes, both contributing sources to the Galactic Rb abundance. We discuss the reliability of these findings for Rb in terms of non-LTE (local thermodynamic equilibrium) effects, stellar activity, or an anomalous Rb abundance in the Solar System, but no explanation is found. We then interpret the full observed [Rb/Fe] versus [Fe/H] trend within the framework of theoretical predictions from state-of-the-art chemical evolution models for heavy elements, but a simple interpretation is not found either. In particular, the possible secondary behaviour of the [Rb/Fe] ratio at super-solar metallicities would require a much larger production of Rb than currently predicted in AGB stars through the s-process without overproducing Sr and Zr. © 2020 ESO.
Published: 2020

16. The CARMENES search for exoplanets around M dwarfs: A deep learning approach to determine fundamental parameters of target stars

Author: German Research Foundation, Max Planck Society, European Commission, Consejo Superior de Investigaciones Científicas (España), Thuringian Ministry of Education, Science and Culture, Klaus Tschira Foundation, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Passegger, V.M., Bello-García, A., Ordieres-Meré, J., Caballero, J. A., Schweitzer, Andreas, González-Marcos, Ana, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Azzaro, M., Bauer, Florian Franz, Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Marfil, E., Montes, D., Morales, Juan Carlos, Nagel, Evangelos, Sarro, L. M., Solano, E., Tabernero, H. M., Zechmeister, Mathias, German Research Foundation, Max Planck Society, European Commission, Consejo Superior de Investigaciones Científicas (España), Thuringian Ministry of Education, Science and Culture, Klaus Tschira Foundation, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Passegger, V.M., Bello-García, A., Ordieres-Meré, J., Caballero, J. A., Schweitzer, Andreas, González-Marcos, Ana, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Azzaro, M., Bauer, Florian Franz, Béjar, Victor J. S., Cortés-Contreras, M., Dreizler, S., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Marfil, E., Montes, D., Morales, Juan Carlos, Nagel, Evangelos, Sarro, L. M., Solano, E., Tabernero, H. M., and Zechmeister, Mathias
Abstract: Existing and upcoming instrumentation is collecting large amounts of astrophysical data, which require efficient and fast analysis techniques. We present a deep neural network architecture to analyze high-resolution stellar spectra and predict stellar parameters such as effective temperature, surface gravity, metallicity, and rotational velocity. With this study, we firstly demonstrate the capability of deep neural networks to precisely recover stellar parameters from a synthetic training set. Secondly, we analyze the application of this method to observed spectra and the impact of the synthetic gap (i.e., the difference between observed and synthetic spectra) on the estimation of stellar parameters, their errors, and their precision. Our convolutional network is trained on synthetic PHOENIX-ACES spectra in different optical and near-infrared wavelength regions. For each of the four stellar parameters, Teff, log g, [M/H], and v sin i, we constructed a neural network model to estimate each parameter independently. We then applied this method to 50 M dwarfs with high-resolution spectra taken with CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Échelle Spectrographs), which operates in the visible (520-960 nm) and near-infrared wavelength range (960-1710 nm) simultaneously. Our results are compared with literature values for these stars. They show mostly good agreement within the errors, but also exhibit large deviations in some cases, especially for [M/H], pointing out the importance of a better understanding of the synthetic gap. © 2020 ESO.
Published: 2020

17. The CARMENES search for exoplanets around M dwarfs. Convective shift and starspot constraints from chromatic radial velocities

Author: German Research Foundation, Max Planck Society, European Commission, Consejo Superior de Investigaciones Científicas (España), Thuringian Ministry of Education, Science and Culture, Klaus Tschira Foundation, Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Baroch, David, Morales, Juan Carlos, Ribas, Ignasi, Herrero, E., Rosich, Albert, Perger, M., Anglada-Escudé, Guillem, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Jeffers, Sandra V., Cifuentes, C., Passegger, V.M., Schweitzer, Andreas, Lafarga, M., Bauer, FF, Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Dreizler, S., Galadí-Enriquez, D., Hatzes, Artie P., Henning, Thomas, Kaminski, Adrian, Kürster, M., Montes, D., Rodríguez-López, Cristina, Zechmeister, Mathias, German Research Foundation, Max Planck Society, European Commission, Consejo Superior de Investigaciones Científicas (España), Thuringian Ministry of Education, Science and Culture, Klaus Tschira Foundation, Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Baroch, David, Morales, Juan Carlos, Ribas, Ignasi, Herrero, E., Rosich, Albert, Perger, M., Anglada-Escudé, Guillem, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Jeffers, Sandra V., Cifuentes, C., Passegger, V.M., Schweitzer, Andreas, Lafarga, M., Bauer, FF, Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Dreizler, S., Galadí-Enriquez, D., Hatzes, Artie P., Henning, Thomas, Kaminski, Adrian, Kürster, M., Montes, D., Rodríguez-López, Cristina, and Zechmeister, Mathias
Abstract: Context. Variability caused by stellar activity represents a challenge to the discovery and characterization of terrestrial exoplanets and complicates the interpretation of atmospheric planetary signals. Aims. We aim to use a detailed modeling tool to reproduce the effect of active regions on radial velocity measurements, which aids the identification of the key parameters that have an impact on the induced variability. Methods. We analyzed the effect of stellar activity on radial velocities as a function of wavelength by simulating the impact of the properties of spots, shifts induced by convective motions, and rotation. We focused our modeling effort on the active star YZ CMi (GJ 285), which was photometrically and spectroscopically monitored with CARMENES and the Telescopi Joan Oró. Results. We demonstrate that radial velocity curves at different wavelengths yield determinations of key properties of active regions, including spot-filling factor, temperature contrast, and location, thus solving the degeneracy between them. Most notably, our model is also sensitive to convective motions. Results indicate a reduced convective shift for M dwarfs when compared to solar-Type stars (in agreement with theoretical extrapolations) and points to a small global convective redshift instead of blueshift. Conclusions. Using a novel approach based on simultaneous chromatic radial velocities and light curves, we can set strong constraints on stellar activity, including an elusive parameter such as the net convective motion effect. © ESO 2020.
Published: 2020

18. A He I upper atmosphere around the warm Neptune GJ 3470 b

Author: Max Planck Society, Consejo Superior de Investigaciones Científicas (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, German Research Foundation, National Natural Science Foundation of China, Natural Science Foundation of Jiangsu Province, Ministerio de Economía y Competitividad (España), Pallé, Enric, Nortmann, L., Casasayas-Barris, N., Lampón, M., López-Puertas, Manuel, Caballero, J. A., Sanz-Forcada, J., Lara, Luisa María, Nagel, Evangelos, Yan, F., Alonso-Floriano, F. Javier, Amado, Pedro J., Chen, G., Cifuentes, C., Cortés-Contreras, M., Czesla, S., Molaverdikhani, K., Montes, D., Passegger, V.M., Quirrenbach, Andreas, Reiners, Ansgar, Ribas, Ignasi, Sánchez-López, A., Schweitzer, Andreas, Stangret, M., Zapatero Osorio, María Rosa, Zechmeister, Mathias, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, German Research Foundation, National Natural Science Foundation of China, Natural Science Foundation of Jiangsu Province, Ministerio de Economía y Competitividad (España), Pallé, Enric, Nortmann, L., Casasayas-Barris, N., Lampón, M., López-Puertas, Manuel, Caballero, J. A., Sanz-Forcada, J., Lara, Luisa María, Nagel, Evangelos, Yan, F., Alonso-Floriano, F. Javier, Amado, Pedro J., Chen, G., Cifuentes, C., Cortés-Contreras, M., Czesla, S., Molaverdikhani, K., Montes, D., Passegger, V.M., Quirrenbach, Andreas, Reiners, Ansgar, Ribas, Ignasi, Sánchez-López, A., Schweitzer, Andreas, Stangret, M., Zapatero Osorio, María Rosa, and Zechmeister, Mathias
Abstract: High resolution transit spectroscopy has proven to be a reliable technique for the characterization of the chemical composition of exoplanet atmospheres. Taking advantage of the broad spectral coverage of the CARMENES spectrograph, we initiated a survey aimed at characterizing a broad range of planetary systems. Here, we report our observations of three transits of GJ 3470 b with CARMENES in search of He (2(3)S) absorption. On one of the nights, the He & x202f;Iregion was heavily contaminated by OH(-)telluric emission and, thus, it was not useful for our purposes. The remaining two nights had a very different signal-to-noise ratio (S/N) due to weather. They both indicate the presence of He (2(3)S) absorption in the transmission spectrum of GJ 3470 b, although a statistically valid detection can only be claimed for the night with higher S/N. For that night, we retrieved a 1.5 +/- 0.3% absorption depth, translating into aR(p)(lambda)/R-p= 1.15 +/- 0.14 at this wavelength. Spectro-photometric light curves for this same night also indicate the presence of extra absorption during the planetary transit with a consistent absorption depth. The He (2(3)S) absorption is modeled in detail using a radiative transfer code, and the results of our modeling efforts are compared to the observations. We find that the mass-loss rate,& x1e40;, is confined to a range of 3 x 10(10)g s(-1)forT= 6000 K to 10 x 10(10)g s(-1)forT= 9000 K. We discuss the physical mechanisms and implications of the He & x202f;Idetection in GJ 3470 b and put it in context as compared to similar detections and non-detections in other Neptune-size planets. We also present improved stellar and planetary parameter determinations based on our visible and near-infrared observations.
Published: 2020

19. The CARMENES search for exoplanets around M dwarfs: different roads to radii and masses of the target stars

Author: Schweitzer, A., Passegger, V.M, Cifuentes, C., Béjar, V.J.S., Cortés Contreras, Miriam, Caballero, J. A., Burgo, C. del, Czesla, S., Kürster, M., Montes Gutiérrez, David, Zapatero Osorio, M.R., Ribas, I., Reiners, A., Quirrenbach, A., Amado, P.J., Aceituno, J., Anglada Escudé, G., Bauer, F.F., Dreizler, S., Jeffers, S.V., Guenther, E.W., Henning, T., Kaminski, A., Lafarga, M., Marfil, E., Morales, J.C., Schmitt, J.H.M.M., Seifert, W., Solano, E., Tabernero, H.M., Zechmeister, M., Schweitzer, A., Passegger, V.M, Cifuentes, C., Béjar, V.J.S., Cortés Contreras, Miriam, Caballero, J. A., Burgo, C. del, Czesla, S., Kürster, M., Montes Gutiérrez, David, Zapatero Osorio, M.R., Ribas, I., Reiners, A., Quirrenbach, A., Amado, P.J., Aceituno, J., Anglada Escudé, G., Bauer, F.F., Dreizler, S., Jeffers, S.V., Guenther, E.W., Henning, T., Kaminski, A., Lafarga, M., Marfil, E., Morales, J.C., Schmitt, J.H.M.M., Seifert, W., Solano, E., Tabernero, H.M., and Zechmeister, M.
Abstract: © ESO 2019. We thank the anonymous referee for a very quick and very constructive report. Furthermore, we thank T. Boyajian and A. W. Mann for helpful discussions during the preparation of this manuscript. CARMENES is an instrument for the Centro Astronómico Hispano-Alemán de Calar Alto (CAHA, Almería, Spain). CARMENES is funded by the German Max-PlanckGesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through FEDER/ERDF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán), with additional contributions by the Spanish Ministry of Science through projects AYA2016-79425-C3-1/2/3- P, ESP2016-80435-C2-1-R, AYA2015-69350-C3-2-P, and AYA2018-84089, the Spanish Ministerio de Educación y Formación Profesional through fellowship FPU15/01476, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía. CdB acknowledges the funding of his sabbatical position through the Mexican national council for science and technology (CONACYT grant CVU No. 448248). This publication makes use of VOSA, developed under the Spanish Virtual Observatory project, the VizieR catalog access tool (Ochsenbein et al. 2000) and the SIMBAD database (Wenger et al. 2000), operated both at CDS, Strasbourg, France, and the interactive graphical viewer and editor for tabular data TOPCAT (Taylor 2005)., Ministerio de Ciencia e Innovación (MICINN)/FEDER, German Max-PlanckGesellschaft (MPG), Consejo Superior de Investigaciones Científicas (CSIC), Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán, Ministerio de Educación y Formación Profesional, German Science Foundation through the Major Research Instrumentation Programme, DFG Research Unit FOR2544 “Blue Planets around Red Stars”, Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, Junta de Andalucía, Spain, Mexican national council for science and technology (CONACYT), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub
Published: 2019

20. The CARMENES search for exoplanets around M dwarfs. Different roads to radii and masses of the target stars

Author: Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, German Research Foundation, Junta de Andalucía, Consejo Nacional de Ciencia y Tecnología (México), Schweitzer, Andreas, Passegger, V.M., Cifuentes, C., Béjar, Victor J. S., Cortés-Contreras, M., Caballero, J. A., Del Burgo, C., Czesla, S., Kürster, M., Montes, D., Zapatero Osorio, María Rosa, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Jesús, Anglada-Escudé, Guillem, Bauer, FF, Dreizler, S., Jeffers, Sandra V., Guenther, E. W., Henning, Thomas, Kaminski, Adrian, Lafarga, M., Marfil, E., Morales, Juan Carlos, Schmitt, Jürgen H. M. M., Seifert, W., Solano, E., Tabernero, H. M., Zechmeister, Mathias, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, German Research Foundation, Junta de Andalucía, Consejo Nacional de Ciencia y Tecnología (México), Schweitzer, Andreas, Passegger, V.M., Cifuentes, C., Béjar, Victor J. S., Cortés-Contreras, M., Caballero, J. A., Del Burgo, C., Czesla, S., Kürster, M., Montes, D., Zapatero Osorio, María Rosa, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Jesús, Anglada-Escudé, Guillem, Bauer, FF, Dreizler, S., Jeffers, Sandra V., Guenther, E. W., Henning, Thomas, Kaminski, Adrian, Lafarga, M., Marfil, E., Morales, Juan Carlos, Schmitt, Jürgen H. M. M., Seifert, W., Solano, E., Tabernero, H. M., and Zechmeister, Mathias
Abstract: Aims: We determine the radii and masses of 293 nearby, bright M dwarfs of the CARMENES survey. This is the first time that such a large and homogeneous high-resolution (R > 80 000) spectroscopic survey has been used to derive these fundamental stellar parameters. Methods: We derived the radii using Stefan-Boltzmann's law. We obtained the required effective temperatures Teff from a spectral analysis and we obtained the required luminosities L from integrated broadband photometry together with the Gaia DR2 parallaxes. The mass was then determined using a mass-radius relation that we derived from eclipsing binaries known in the literature. We compared this method with three other methods: (1) We calculated the mass from the radius and the surface gravity log g, which was obtained from the same spectral analysis as Teff. (2) We used a widely used infrared mass-magnitude relation. (3) We used a Bayesian approach to infer stellar parameters from the comparison of the absolute magnitudes and colors of our targets with evolutionary models. Results: Between spectral types M0 V and M7 V our radii cover the range 0.1 R¿ < R < 0.6 R¿ with an error of 2-3% and our masses cover 0.09 ¿¿ < ¿< 0.6¿¿ with an error of 3-5%. We find good agreement between the masses determined with these different methods for most of our targets. Only the masses of very young objects show discrepancies. This can be well explained with the assumptions that we used for our methods. c ESO 2019
Published: 2019

21. The CARMENES search for exoplanets around M dwarfs: Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital parameters of a super-Earth around GJ 686 (BD+18 3421)

Author: Generalitat de Catalunya, Israel Science Foundation, German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Lalitha, S., Baroch, David, Morales, Juan Carlos, Passegger, V.M., Bauer, FF, Cardona Guillén, C., Dreizler, S., Oshagh, M., Reiners, Ansgar, Ribas, Ignasi, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Galadí-Enriquez, D., González-Cuesta, L., Guenther, E. W., Hagen, Hans-Jürgen, Henning, Thomas, Herrero, E., Husser, T. O., Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Lodieu, N., López González, Maria J., Montes, D., Perger, M., Rosich, Albert, Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Schmitt, Jürgen H. M. M., Tal-Or, L., Zechmeister, Mathias, Generalitat de Catalunya, Israel Science Foundation, German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Lalitha, S., Baroch, David, Morales, Juan Carlos, Passegger, V.M., Bauer, FF, Cardona Guillén, C., Dreizler, S., Oshagh, M., Reiners, Ansgar, Ribas, Ignasi, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Galadí-Enriquez, D., González-Cuesta, L., Guenther, E. W., Hagen, Hans-Jürgen, Henning, Thomas, Herrero, E., Husser, T. O., Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Lodieu, N., López González, Maria J., Montes, D., Perger, M., Rosich, Albert, Rodríguez Martínez, Eloy, Rodríguez-López, Cristina, Schmitt, Jürgen H. M. M., Tal-Or, L., and Zechmeister, Mathias
Abstract: Although M dwarfs are known for high levels of stellar activity, they are ideal targets for the search of low-mass exoplanets with the radial velocity (RV) method. We report the discovery of a planetary-mass companion around LSPM J2116+0234 (M3.0 V) and confirm the existence of a planet orbiting GJ 686 (BD+18 3421; M1.0 V). The discovery of the planet around LSPM J2116+0234 is based on CARMENES RV observations in the visual and near-infrared channels. We confirm the planet orbiting around GJ 686 by analyzing the RV data spanning over two decades of observationsfrom CARMENES VIS, HARPS-N, HARPS, and HIRES. We find planetary signals at 14.44 and 15.53 d in the RV data for LSPM J2116+0234 and GJ 686, respectively. Additionally, the RV, photometric time series, and various spectroscopic indicators show hints of variations of 42 d for LSPM J2116+0234 and 37 d for GJ 686, which we attribute to the stellar rotation periods. The orbital parameters of the planets are modeled with Keplerian fits together with correlated noise from the stellar activity. A mini-Neptune with a minimum mass of 11.8 M orbits LSPM J2116+0234 producing a RV semi-amplitude of 6.19 m s, while a super-Earth of mass 6.6 M orbits GJ 686 and produces a RV semi-amplitude of 3.0 m s. Both LSPM J2116+0234 and GJ 686 have planetary companions populating the regime of exoplanets with masses lower than 15 M and orbital periods <20 d.© ESO 2019.
Published: 2019

22. The CARMENES search for exoplanets around M dwarfs: The enigmatic planetary system GJ 4276: One eccentric planet or two planets in a 2:1 resonance

Author: Junta de Andalucía, German Research Foundation, Ministerio de Ciencia e Innovación (España), Consejo Superior de Investigaciones Científicas (España), Max Planck Society, European Commission, Nagel, Evangelos, Czesla, S., Schmitt, Jürgen H. M. M., Dreizler, S., Anglada-Escudé, Guillem, Rodríguez Martínez, Eloy, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Caballero, J. A., Aceituno, Francisco José, Béjar, Victor J. S., Cortés-Contreras, M., González-Cuesta, L., Guenther, E. W., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López González, Maria J., Montes, D., Morales, Juan Carlos, Passegger, V.M., Rodríguez-López, Cristina, Schweitzer, Andreas, Zechmeister, Mathias, Junta de Andalucía, German Research Foundation, Ministerio de Ciencia e Innovación (España), Consejo Superior de Investigaciones Científicas (España), Max Planck Society, European Commission, Nagel, Evangelos, Czesla, S., Schmitt, Jürgen H. M. M., Dreizler, S., Anglada-Escudé, Guillem, Rodríguez Martínez, Eloy, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Caballero, J. A., Aceituno, Francisco José, Béjar, Victor J. S., Cortés-Contreras, M., González-Cuesta, L., Guenther, E. W., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., López González, Maria J., Montes, D., Morales, Juan Carlos, Passegger, V.M., Rodríguez-López, Cristina, Schweitzer, Andreas, and Zechmeister, Mathias
Abstract: We report the detection of a Neptune-mass exoplanet around the M4.0 dwarf GJ 4276 (G 232-070) based on radial velocity (RV) observations obtained with the CARMENES spectrograph. The RV variations of GJ 4276 are best explained by the presence of a planetary companion that has a minimum mass of mb sin i 16 M on a Pb = 13.35 day orbit. The analysis of the activity indicators and spectral diagnostics exclude stellar induced RV perturbations and prove the planetary interpretation of the RV signal. We show that a circular single-planet solution can be excluded by means of a likelihood ratio test. Instead, we find that the RV variations can be explained either by an eccentric orbit or interpreted as a pair of planets on circular orbits near a period ratio of 2:1. Although the eccentric single-planet solution is slightly preferred, our statistical analysis indicates that none of these two scenarios can be rejected with high confidence using the RV time series obtained so far. Based on the eccentric interpretation, we find that GJ 4276 b is the most eccentric (eb = 0.37) exoplanet around an M dwarf with such a short orbital period known today.© ESO 2019.
Published: 2019

23. The CARMENES search for exoplanets around M dwarfs. High-resolution optical and near-infrared spectroscopy of 324 survey stars

Author: Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Reiners, A., Zechmeister, M., Caballero, J.A., Ribas, I., Morales, J.C., Jeffers, S.V., Schöfer, P., Tal-Or, L., Quirrenbach, A., Amado, P.J., Kaminski, A., Blümcke, M., Brinkmöller, M., Burgo, C. del, Cano, J., Cárdenas Vázquez, M.C., Casal, E., Cifuentes, C., Claret, A., Colomé, J., Cortés-Contreras, M., Maroto Fernández, D., Czesla, S., Díez-Alonso, E., Dreizler, S., Feiz, C., Fernández, M., Ferro, I.M., Fuhrmeister, B., Galadí-Enríquez, D., Garcia-Piquer, A., García Vargas, M.L., Martín, E.L., Gesa, L., Gómez Galera, V., González Hernández, J.I., González-Peinado, R., Grözinger, U., Grohnert, S., Guàrdia, J., Guenther, E.W., Guijarro, A., Guindos, E. de, Martín-Ruiz, S., Gutiérrez-Soto, J., Hagen, H.-J., Hatzes, A.P., Hauschildt, P.H., Hedrosa, R.P., Helmling, J., Henning, Th., Hermelo, I., Hernández Arabí, R., Hernández Castaño, L., Marvin, C.J., Hernández Hernando, F., Herrero, E., Huber, A., Huke, P., Johnson, E.N., Juan, E. de, Kim, M., Klein, R., Klüter, J., Klutsch, A., Mathar, R.J., Kürster, M., Lafarga, M., Lamert, A., Lampón, M., Lara, L.M., Laun, W., Lemke, U., Lenzen, R., Launhardt, R., López del Fresno, M., Mirabet, E., López-González, J., López-Puertas, M., López Salas, J.F., López-Santiago, J., Luque, R., Magán Madinabeitia, H., Mall, U., Mancini, L., Mandel, H., Marfil, E., Montes, D., Marín Molina, J.A., Moreno-Raya, M.E., Moya, A., Mundt, R., Seifert, W., Nagel, E., Naranjo, V., Nortmann, L., Nowak, G., Ofir, A., Oreiro, R., Pallé, E., Panduro, J., Pascual, J., Passegger, V.M., Abril, M., Pavlov, A., Pedraz, S., Pérez-Calpena, A., Pérez Medialdea, D., Perger, M., Perryman, M.A.C., Pluto, M., Rabaza, O., Ramón, A., Rebolo, R., Aceituno, J., Redondo, P., Reffert, S., Reinhart, S., Rhode, P., Rix, H.-W., Rodler, F., Rodríguez, E., Rodríguez-López, C., Rodríguez Trinidad, A., Rohloff, R.-R., Alonso-Floriano, F.J., Rosich, A., Sadegi, S., Sánchez-Blanco, E., Sánchez Carrasco, M.A., Sánchez-López, A., Sanz-Forcada, J., Sarkis, P., Sarmiento, L.F., Schäfer, S., Schmitt, J.H.M.M., Ammler-von Eiff, M., Schiller, J., Schweitzer, A., Solano, Enrique, Stahl, O., Strachan, J.B.P., Stürmer, J., Suárez, J.C., Tabernero, Hugo M., Tala, M., Trifonov, T., Antona, R., Tulloch, S.M., Ulbrich, R.G., Veredas, G., Vico Linares, J.I., Vilardell Sallés, Francesc, Wagner, K., Winkler, J., Wolthoff, V., Xu, W., Yan, F., Anglada-Escudé, G., Zapatero Osorio, M.R., Anwand-Heerwart, H., Arroyo-Torres, B., Azzaro, M., Baroch, D., Barrado, D., Bauer, F.F., Becerril, S., Béjar, V.J.S., Benítez, D., Berdinas̃, Z.M., Bergond, G., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Reiners, A., Zechmeister, M., Caballero, J.A., Ribas, I., Morales, J.C., Jeffers, S.V., Schöfer, P., Tal-Or, L., Quirrenbach, A., Amado, P.J., Kaminski, A., Blümcke, M., Brinkmöller, M., Burgo, C. del, Cano, J., Cárdenas Vázquez, M.C., Casal, E., Cifuentes, C., Claret, A., Colomé, J., Cortés-Contreras, M., Maroto Fernández, D., Czesla, S., Díez-Alonso, E., Dreizler, S., Feiz, C., Fernández, M., Ferro, I.M., Fuhrmeister, B., Galadí-Enríquez, D., Garcia-Piquer, A., García Vargas, M.L., Martín, E.L., Gesa, L., Gómez Galera, V., González Hernández, J.I., González-Peinado, R., Grözinger, U., Grohnert, S., Guàrdia, J., Guenther, E.W., Guijarro, A., Guindos, E. de, Martín-Ruiz, S., Gutiérrez-Soto, J., Hagen, H.-J., Hatzes, A.P., Hauschildt, P.H., Hedrosa, R.P., Helmling, J., Henning, Th., Hermelo, I., Hernández Arabí, R., Hernández Castaño, L., Marvin, C.J., Hernández Hernando, F., Herrero, E., Huber, A., Huke, P., Johnson, E.N., Juan, E. de, Kim, M., Klein, R., Klüter, J., Klutsch, A., Mathar, R.J., Kürster, M., Lafarga, M., Lamert, A., Lampón, M., Lara, L.M., Laun, W., Lemke, U., Lenzen, R., Launhardt, R., López del Fresno, M., Mirabet, E., López-González, J., López-Puertas, M., López Salas, J.F., López-Santiago, J., Luque, R., Magán Madinabeitia, H., Mall, U., Mancini, L., Mandel, H., Marfil, E., Montes, D., Marín Molina, J.A., Moreno-Raya, M.E., Moya, A., Mundt, R., Seifert, W., Nagel, E., Naranjo, V., Nortmann, L., Nowak, G., Ofir, A., Oreiro, R., Pallé, E., Panduro, J., Pascual, J., Passegger, V.M., Abril, M., Pavlov, A., Pedraz, S., Pérez-Calpena, A., Pérez Medialdea, D., Perger, M., Perryman, M.A.C., Pluto, M., Rabaza, O., Ramón, A., Rebolo, R., Aceituno, J., Redondo, P., Reffert, S., Reinhart, S., Rhode, P., Rix, H.-W., Rodler, F., Rodríguez, E., Rodríguez-López, C., Rodríguez Trinidad, A., Rohloff, R.-R., Alonso-Floriano, F.J., Rosich, A., Sadegi, S., Sánchez-Blanco, E., Sánchez Carrasco, M.A., Sánchez-López, A., Sanz-Forcada, J., Sarkis, P., Sarmiento, L.F., Schäfer, S., Schmitt, J.H.M.M., Ammler-von Eiff, M., Schiller, J., Schweitzer, A., Solano, Enrique, Stahl, O., Strachan, J.B.P., Stürmer, J., Suárez, J.C., Tabernero, Hugo M., Tala, M., Trifonov, T., Antona, R., Tulloch, S.M., Ulbrich, R.G., Veredas, G., Vico Linares, J.I., Vilardell Sallés, Francesc, Wagner, K., Winkler, J., Wolthoff, V., Xu, W., Yan, F., Anglada-Escudé, G., Zapatero Osorio, M.R., Anwand-Heerwart, H., Arroyo-Torres, B., Azzaro, M., Baroch, D., Barrado, D., Bauer, F.F., Becerril, S., Béjar, V.J.S., Benítez, D., Berdinas̃, Z.M., and Bergond, G.
Published: 2018

24. CARMENES: high-resolution spectra and precise radial velocities in the red and infrared

Author: Quirrenbach, Andreas, Amado, Pedro J., Ribas, Ignasi, Reiners, Ansgar, Caballero, J. A., Seifert, W., Aceituno, Jesús, Azzaro, M., Baroch, David, Barrado y Navascués, David, Bauer, Florian Franz, Kehr, M., Pavlov, A., Fernández, Matilde, Hernández Hernando, F., Schäfer, S., Cortés-Contreras, M., Abellán, F. J., Guàrdia, J., Cardona Guillén, C., Mundt, R., Mandel, H., Abril, Miguel, Zhao, Z., Alonso-Floriano, F. Javier, Ammler-von Eiff, M., Anglada-Escudé, Guillem, Huke, P., Lara, Luisa María, Tal-Or, L., Moya, A., López Salas, J.F., Moreno-Raya, M.E., Storz, C., Anwand-Heerwart, H., Reffert, S., Gaisné, G., Hernández Castaño, L., Gallardo, I., Gálvez-Ortiz, M. C., García-Piquer, A., Lodieu, N., Passegger, V.M., Galadí-Enriquez, D., Czesla, S., Schmidt, C., Perryman, M. A. C., Sarmiento, L. F., Brinkmöller, M., García-Vargas, M. L., Tala Pinto, M., Guijarro, A., López-Puertas, Manuel, Hedrosa, R.P., Lampón, M., Hermann, D., Hermelo, I., Panduro, J., Schmitt, Jürgen H. M. M., Jeffers, Sandra V., Dreizler, S., Benítez, D., Tulloch, S.M., Béjar, Victor J. S., López-Santiago, J., Rohloff, R.-R., Hernández Arabí, R., Claret dos Santos, Antonio, Klüter, J., Perger, M., Klutsch, A., Pallé, Enric, Labarga, F., Labiche, N., Stürmer, J., Blümcke, M., Berdiñas, Z. M., Marfil, E., Herbort, O., Lamert, A., Fuhrmeister, Birgit, Holgado, G., Pluto, M., Wolthoff, V., Laun, W., Trifonov, T., Magán Madinabeitia, H., Veredas, G., Solano, E., Mall, U., Schiller, J., Mancini, L., Marín Molina, J.A., Cifuentes, C., Frölich, K., Gesa, Lluis, Rodríguez Martínez, Eloy, López del Fresno, M., Johnson, E.N., Martínez-Rodríguez, Héctor, Hintz, D., Lenzen, R., Ulbrich, R.G., Hauschildt, P. H., Maroto Fernández, D., Díez-Alonso, E., Ramón, A., González Hernández, Jonay I., Cárdenas Vázquez, María Concepción, Pérez Medialdea, D., Redondo, P., Bergondy, G., Reinhart, S., Rhode, P., Rix, H.-W., Herrero, E., Hidalgo, D., Zapatero Osorio, María Rosa, Pedraz, S., Martín, Eduardo Lorenzo, Shulyak, D., Rodler, F., López González, Maria J., Vico Linares, J. L., González-Álvarez, E., Vidal Dasilva, Manuela, Vilardell, Francesc, Wagner, K., Luque, R., Lemke, U., Doellinger, M., Schweitzer, Andreas, Rodríguez-López, Cristina, Schöfer, P., Carro, J., Winkler, J., Pascual, J., González Peinado, R., Huber, K., Guenther, E. W., de Guindos, E., Hagen, Hans-Jürgen, Rebolo López, Rafael, Miralda-Escudé, Jordi, Grözinger, U., Dorda, R., Cano, J., Yan, F., Del Burgo, C., Martín-Ruiz, Susana, Hatzes, Artie P., Suárez Yanes, Juan Carlos, de Juan, E., Lizon, J. -L., Kaminski, Adrian, Lázaro, F. J., Klahr, H., Kürster, M., Stahl, O., Sánchez Carrasco, Miguel Andrés, Kim, M., Gómez Galera, V., Lafarga, M., Feiz, C., Henning, Thomas, Rosich, Albert, Arroyo-Torres, B., Sairam, L., Colomé, J., Mathar, R.J., Naranjo, V., Montes, D., Marvin, C. J., Morales, Juan Carlos, Nagel, Evangelos, Casal, E., Becerril, S., Xu, W., López-Morales, Mercedes, Huber, A., Nortmann, L., Grohnert, S., Launhardt, R., Zechmeister, Mathias, Garrido, Rafael, Nowak, G., Tabernero, H. M., Sabotta, S., Ferro, I.M., Strachan, J. B. P., Sadegi, S., Sánchez-Blanco, E., Salz, M., Sánchez-López, A., Sanz-Forcada, J., González-Cuesta, L., Helmling, J., Pérez-Calpena, A., Llamas, M., Klein, R., Sarkis, Paula, Quirrenbach, Andreas, Amado, Pedro J., Ribas, Ignasi, Reiners, Ansgar, Caballero, J. A., Seifert, W., Aceituno, Jesús, Azzaro, M., Baroch, David, Barrado y Navascués, David, Bauer, Florian Franz, Kehr, M., Pavlov, A., Fernández, Matilde, Hernández Hernando, F., Schäfer, S., Cortés-Contreras, M., Abellán, F. J., Guàrdia, J., Cardona Guillén, C., Mundt, R., Mandel, H., Abril, Miguel, Zhao, Z., Alonso-Floriano, F. Javier, Ammler-von Eiff, M., Anglada-Escudé, Guillem, Huke, P., Lara, Luisa María, Tal-Or, L., Moya, A., López Salas, J.F., Moreno-Raya, M.E., Storz, C., Anwand-Heerwart, H., Reffert, S., Gaisné, G., Hernández Castaño, L., Gallardo, I., Gálvez-Ortiz, M. C., García-Piquer, A., Lodieu, N., Passegger, V.M., Galadí-Enriquez, D., Czesla, S., Schmidt, C., Perryman, M. A. C., Sarmiento, L. F., Brinkmöller, M., García-Vargas, M. L., Tala Pinto, M., Guijarro, A., López-Puertas, Manuel, Hedrosa, R.P., Lampón, M., Hermann, D., Hermelo, I., Panduro, J., Schmitt, Jürgen H. M. M., Jeffers, Sandra V., Dreizler, S., Benítez, D., Tulloch, S.M., Béjar, Victor J. S., López-Santiago, J., Rohloff, R.-R., Hernández Arabí, R., Claret dos Santos, Antonio, Klüter, J., Perger, M., Klutsch, A., Pallé, Enric, Labarga, F., Labiche, N., Stürmer, J., Blümcke, M., Berdiñas, Z. M., Marfil, E., Herbort, O., Lamert, A., Fuhrmeister, Birgit, Holgado, G., Pluto, M., Wolthoff, V., Laun, W., Trifonov, T., Magán Madinabeitia, H., Veredas, G., Solano, E., Mall, U., Schiller, J., Mancini, L., Marín Molina, J.A., Cifuentes, C., Frölich, K., Gesa, Lluis, Rodríguez Martínez, Eloy, López del Fresno, M., Johnson, E.N., Martínez-Rodríguez, Héctor, Hintz, D., Lenzen, R., Ulbrich, R.G., Hauschildt, P. H., Maroto Fernández, D., Díez-Alonso, E., Ramón, A., González Hernández, Jonay I., Cárdenas Vázquez, María Concepción, Pérez Medialdea, D., Redondo, P., Bergondy, G., Reinhart, S., Rhode, P., Rix, H.-W., Herrero, E., Hidalgo, D., Zapatero Osorio, María Rosa, Pedraz, S., Martín, Eduardo Lorenzo, Shulyak, D., Rodler, F., López González, Maria J., Vico Linares, J. L., González-Álvarez, E., Vidal Dasilva, Manuela, Vilardell, Francesc, Wagner, K., Luque, R., Lemke, U., Doellinger, M., Schweitzer, Andreas, Rodríguez-López, Cristina, Schöfer, P., Carro, J., Winkler, J., Pascual, J., González Peinado, R., Huber, K., Guenther, E. W., de Guindos, E., Hagen, Hans-Jürgen, Rebolo López, Rafael, Miralda-Escudé, Jordi, Grözinger, U., Dorda, R., Cano, J., Yan, F., Del Burgo, C., Martín-Ruiz, Susana, Hatzes, Artie P., Suárez Yanes, Juan Carlos, de Juan, E., Lizon, J. -L., Kaminski, Adrian, Lázaro, F. J., Klahr, H., Kürster, M., Stahl, O., Sánchez Carrasco, Miguel Andrés, Kim, M., Gómez Galera, V., Lafarga, M., Feiz, C., Henning, Thomas, Rosich, Albert, Arroyo-Torres, B., Sairam, L., Colomé, J., Mathar, R.J., Naranjo, V., Montes, D., Marvin, C. J., Morales, Juan Carlos, Nagel, Evangelos, Casal, E., Becerril, S., Xu, W., López-Morales, Mercedes, Huber, A., Nortmann, L., Grohnert, S., Launhardt, R., Zechmeister, Mathias, Garrido, Rafael, Nowak, G., Tabernero, H. M., Sabotta, S., Ferro, I.M., Strachan, J. B. P., Sadegi, S., Sánchez-Blanco, E., Salz, M., Sánchez-López, A., Sanz-Forcada, J., González-Cuesta, L., Helmling, J., Pérez-Calpena, A., Llamas, M., Klein, R., and Sarkis, Paula
Abstract: The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument at the 3.5m telescope of the Calar Alto Observatory, which was built by a consortium of eleven Spanish and German institutions. CARMENES consists of two separate échelle spectrographs covering the wavelength range from 0.52 to 1.71¿m at a spec-tral resolution of R < 80,000, fed by fibers from the Cassegrain focus of the telescope. CARMENES saw ¿First Light¿ on Nov 9, 2015. During the commissioning and initial operation phases, we established basic performance data such as throughput and spectral resolution. We found that our hollow-cathode lamps are suitable for precise wavelength calibration, but their spectra contain a number of lines of neon or argon that are so bright that the lamps cannot be used in simultaneous exposures with stars. We have therefore adopted a calibration procedure that uses simultaneous star / Fabry Pérot etalon exposures in combination with a cross-calibration between the etalons and hollow-cathode lamps during daytime. With this strategy it has been possible to achieve 1-2 m/s precision in the visible and 5-10 m/s precision in the near-IR; further improvements are expected from ongoing work on temperature control, calibration procedures and data reduction. Comparing the RV precision achieved in different wavelength bands, we find a ¿sweet spot¿ between 0.7 and 0.8¿m, where deep TiO bands provide rich RV information in mid-M dwarfs. This is in contrast to our pre-survey models, which predicted comparatively better performance in the near-IR around 1¿m, and explains in part why our near-IR RVs do not reach the same precision level as those taken with the visible spectrograph. We are now conducting a large survey of 340 nearby M dwarfs (with an average distance of only 12pc), with the goal of finding terrestrial planets in their habitable zones. We have detected the signatures of several previously known o
Published: 2018

25. The CARMENES search for exoplanets around M dwarfs Photospheric parameters of target stars from high-resolution spectroscopy

Author: Ministerio de Economía y Competitividad (España), European Commission, Junta de Andalucía, Passegger, V.M., Reiners, Ansgar, Jeffers, Sandra V., Wende-von Berg, S., Schöfer, P., Caballero, J. A., Schweitzer, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cortés-Contreras, M., Hatzes, Artie P., Kürster, M., Montes, D., Pedraz, S., Quirrenbach, Andreas, Ribas, Ignasi, Seifert, W., Ministerio de Economía y Competitividad (España), European Commission, Junta de Andalucía, Passegger, V.M., Reiners, Ansgar, Jeffers, Sandra V., Wende-von Berg, S., Schöfer, P., Caballero, J. A., Schweitzer, Andreas, Amado, Pedro J., Béjar, Victor J. S., Cortés-Contreras, M., Hatzes, Artie P., Kürster, M., Montes, D., Pedraz, S., Quirrenbach, Andreas, Ribas, Ignasi, and Seifert, W.
Abstract: The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Aims. Characterising our target sample is important for constraining the physical properties of any planetary systems that are detected. The aim of this paper is to determine the fundamental stellar parameters of the CARMENES M-dwarf target sample from high-resolution spectra observed with CARMENES. We also include several M-dwarf spectra observed with other high-resolution spectrographs, that is CAFE, FEROS, and HRS, for completeness. Methods. We used a chi(2) method to derive the stellar parameters effective temperature T-eff, surface gravity log g, and metallicity [Fe/H] of the target stars by fitting the most recent version of the PHOENIX-ACES models to high-resolution spectroscopic data. These stellar atmosphere models incorporate a new equation of state to describe spectral features of low-temperature stellar atmospheres. Since Teff, log g, and [Fe/H] show degeneracies, the surface gravity is determined independently using stellar evolutionary models. Results. We derive the stellar parameters for a total of 300 stars. The fits achieve very good agreement between the PHOENIX models and observed spectra. We estimate that our method provides parameters with uncertainties of sigma(Teff) = 51 K, sigma(logg) = 0 : 07, and sigma[(Fe/H)] = 0.16, and show that atmosphere models for low-mass stars have significantly improved in the last years. Our work also provides an independent test of the new PHOENIX-ACES models, and a comparison for other methods using low-resolution spectra. In particular, our effective temperatures agree well with literature values, while metallicities determined with our method exhibit a larger spread when compared to literature results.© ESO 2018.
Published: 2018

26. The CARMENES search for exoplanets around M dwarfs: The warm super-Earths in twin orbits around the mid-type M dwarfs Ross 1020 (GJ 3779) and LP 819-052 (GJ 1265)

Author: Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Research and Art Baden-Württemberg, German Research Foundation, Junta de Andalucía, La Caixa, Luque, R., Nowak, G., Pallé, Enric, Kossakowski, D., Trifonov, T., Zechmeister, Mathias, Béjar, Victor J. S., Guillén, C. C., Tal-Or, L., Hidalgo, D., Ribas, Ignasi, Reiners, Ansgar, Caballero, J. A., Amado, Pedro J., Quirrenbach, Andreas, Aceituno, Jesús, Cortés-Contreras, M., Díez-Alonso, E., Dreizler, S., Guenther, E. W., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Montes, D., Morales, Juan Carlos, Passegger, V.M., Schmitt, Jürgen H. M. M., Schweitzer, Andreas, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Research and Art Baden-Württemberg, German Research Foundation, Junta de Andalucía, La Caixa, Luque, R., Nowak, G., Pallé, Enric, Kossakowski, D., Trifonov, T., Zechmeister, Mathias, Béjar, Victor J. S., Guillén, C. C., Tal-Or, L., Hidalgo, D., Ribas, Ignasi, Reiners, Ansgar, Caballero, J. A., Amado, Pedro J., Quirrenbach, Andreas, Aceituno, Jesús, Cortés-Contreras, M., Díez-Alonso, E., Dreizler, S., Guenther, E. W., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kürster, M., Lafarga, M., Montes, D., Morales, Juan Carlos, Passegger, V.M., Schmitt, Jürgen H. M. M., and Schweitzer, Andreas
Abstract: We announce the discovery of two planetary companions orbiting around the low-mass stars Ross 1020 (GJ 3779, M4.0V) and LP 819-052 (GJ 1265, M4.5V). The discovery is based on the analysis of CARMENES radial velocity (RV) observations in the visual channel as part of its survey for exoplanets around M dwarfs. In the case of GJ 1265, CARMENES observations were complemented with publicly available Doppler measurements from HARPS. The datasets reveal two planetary companions, one for each star, that share very similar properties: minimum masses of 8.0 ± 0.5 M and 7.4 ± 0.5 M in low-eccentricity orbits with periods of 3.023 ± 0.001 d and 3.651 ± 0.001 d for GJ 3779 b and GJ 1265 b, respectively. The periodic signals around 3 d found in the RV data have no counterpart in any spectral activity indicator. Furthermore, we collected available photometric data for the two host stars, which confirm that the additional Doppler variations found at periods of approximately 95 d can be attributed to the rotation of the stars. The addition of these planets to a mass-period diagram of known planets around M dwarfs suggests a bimodal distribution with a lack of short-period low-mass planets in the range of 2-5 M . It also indicates that super-Earths (>5 M ) currently detected by RV and transit techniques around M stars are usually found in systems dominated by a single planet.© ESO 2018.
Published: 2018

27. The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars

Author: Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Ministry of Science, Research and Art Baden-Württemberg, German Research Foundation, Junta de Andalucía, Universidad Complutense de Madrid, Ministerio de Ciencia, Innovación y Universidades (España), Comisión Nacional de Investigación Científica y Tecnológica (Chile), German Centre for Air and Space Travel, European Research Council, Reiners, Ansgar, Zechmeister, Mathias, Caballero, J. A., Ribas, Ignasi, Morales, Juan Carlos, Jeffers, Sandra V., Schöfer, P., Tal-Or, L., Quirrenbach, Andreas, Amado, Pedro J., Kaminski, Adrian, Sarmiento, L. F., García Vargas, M. L., Laun, W., Marvin, C. J., Ammler-von Eiff, M., Martín, Eduardo Lorenzo, López-Puertas, Manuel, Henning, Thomas, Schmitt, Jürgen H. M. M., Rodler, F., Hernández Hernando, F., Schiller, J., Schweitzer, Andreas, Ulbrich, R.G., Mancini, L., Stürmer, J., Solano, E., Grohnert, S., Anwand-Heerwart, H., Helmling, J., Kürster, M., Sánchez-López, A., Wolthoff, V., Lampón, M., Ferro, I.M., Klutsch, A., Fuhrmeister, Birgit, Fernández, Matilde, Béjar, Victor J. S., Huke, P., Hernández Arabí, R., Herrero, E., Tala, M., de Juan, E., Baroch, David, Blümcke, M., Montes, D., Moya, A., Del Burgo, C., Guindos, E. D., Rodríguez Martínez, Eloy, López González, Maria J., Cano, J., Czesla, S., Cárdenas Vázquez, María Concepción, Casal, E., Aceituno, Jesús, Marfil, E., Yan, F., Rhode, P., Magán Madinabeitia, H., Lenzen, R., Nagel, Evangelos, Gesa, Lluis, Kim, M., Cortés-Contreras, M., Mundt, R., Hedrosa, R.P., Galera, V. G., González Hernández, Jonay I., López Salas, J.F., Luque, R., Marín Molina, J.A., Wagner, K., Guijarro, A., Mathar, R.J., Zapatero Osorio, María Rosa, Gutiérrez-Soto, J., Cifuentes, C., Abril, Miguel, Hagen, Hans-Jürgen, Miralda-Escudé, Jordi, Vilardell, Francesc, Azzaro, M., Naranjo, V., Mandel, H., Anglada-Escudé, Guillem, Trifonov, T., Claret dos Santos, Antonio, Klein, R., Guàrdia, J., Rodríguez-López, Cristina, Klüter, J., Lemke, U., Panduro, J., Passegger, V.M., Martín-Ruiz, Susana, Redondo, P., Sanz-Forcada, J., Winkler, J., Pavlov, A., Sadegi, S., Bergond, G., Pérez-Calpena, A., Reffert, S., Veredas, G., Rosich, Albert, Launhardt, R., Reinhart, S., Sánchez-Blanco, E., López del Fresno, M., Rix, H.-W., Barrado y Navascués, David, Johnson, E.N., Rebolo López, Rafael, Hauschildt, P. H., López-Santiago, J., Suárez, J.C., Stahl, O., Pérez Medialdea, D., Perryman, M. A. C., Lara, Luisa María, Becerril, S., Sánchez Carrasco, Miguel Andrés, Moreno-Raya, M.E., Xu, W., Strachan, J. B. P., Bauer, Florian Franz, Schäfer, S., Seifert, W., Grözinger, U., Perger, M., Hatzes, Artie P., Benítez, D., Nortmann, L., Rodríguez Trinidad, A., Hernández Castaño, L., Lamert, A., Nowak, G., Ofir, A., Oreiro, Raquel, Tulloch, S.M., Maroto Fernández, D., Pallé, Enric, Hermelo, I., Vico Linares, J.I., Arroyo-Torres, B., Tabernero, H. M., Pluto, M., Lafarga, M., Dreizler, S., Huber, A., Rabaza, O., Ramón, A., Berdiñas, Z. M., Brinkmöller, M., Antona, R., Pedraz, S., Feiz, C., González-Peinado, R., Sarkis, Paula, Pascual Granado, J., Guenther, E. W., Alonso-Floriano, F. Javier, Colomé, J., Díez-Alonso, E., García-Piquer, A., Mall, U., Rohloff, R.-R., Galadí-Enriquez, D., Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Ministry of Science, Research and Art Baden-Württemberg, German Research Foundation, Junta de Andalucía, Universidad Complutense de Madrid, Ministerio de Ciencia, Innovación y Universidades (España), Comisión Nacional de Investigación Científica y Tecnológica (Chile), German Centre for Air and Space Travel, European Research Council, Reiners, Ansgar, Zechmeister, Mathias, Caballero, J. A., Ribas, Ignasi, Morales, Juan Carlos, Jeffers, Sandra V., Schöfer, P., Tal-Or, L., Quirrenbach, Andreas, Amado, Pedro J., Kaminski, Adrian, Sarmiento, L. F., García Vargas, M. L., Laun, W., Marvin, C. J., Ammler-von Eiff, M., Martín, Eduardo Lorenzo, López-Puertas, Manuel, Henning, Thomas, Schmitt, Jürgen H. M. M., Rodler, F., Hernández Hernando, F., Schiller, J., Schweitzer, Andreas, Ulbrich, R.G., Mancini, L., Stürmer, J., Solano, E., Grohnert, S., Anwand-Heerwart, H., Helmling, J., Kürster, M., Sánchez-López, A., Wolthoff, V., Lampón, M., Ferro, I.M., Klutsch, A., Fuhrmeister, Birgit, Fernández, Matilde, Béjar, Victor J. S., Huke, P., Hernández Arabí, R., Herrero, E., Tala, M., de Juan, E., Baroch, David, Blümcke, M., Montes, D., Moya, A., Del Burgo, C., Guindos, E. D., Rodríguez Martínez, Eloy, López González, Maria J., Cano, J., Czesla, S., Cárdenas Vázquez, María Concepción, Casal, E., Aceituno, Jesús, Marfil, E., Yan, F., Rhode, P., Magán Madinabeitia, H., Lenzen, R., Nagel, Evangelos, Gesa, Lluis, Kim, M., Cortés-Contreras, M., Mundt, R., Hedrosa, R.P., Galera, V. G., González Hernández, Jonay I., López Salas, J.F., Luque, R., Marín Molina, J.A., Wagner, K., Guijarro, A., Mathar, R.J., Zapatero Osorio, María Rosa, Gutiérrez-Soto, J., Cifuentes, C., Abril, Miguel, Hagen, Hans-Jürgen, Miralda-Escudé, Jordi, Vilardell, Francesc, Azzaro, M., Naranjo, V., Mandel, H., Anglada-Escudé, Guillem, Trifonov, T., Claret dos Santos, Antonio, Klein, R., Guàrdia, J., Rodríguez-López, Cristina, Klüter, J., Lemke, U., Panduro, J., Passegger, V.M., Martín-Ruiz, Susana, Redondo, P., Sanz-Forcada, J., Winkler, J., Pavlov, A., Sadegi, S., Bergond, G., Pérez-Calpena, A., Reffert, S., Veredas, G., Rosich, Albert, Launhardt, R., Reinhart, S., Sánchez-Blanco, E., López del Fresno, M., Rix, H.-W., Barrado y Navascués, David, Johnson, E.N., Rebolo López, Rafael, Hauschildt, P. H., López-Santiago, J., Suárez, J.C., Stahl, O., Pérez Medialdea, D., Perryman, M. A. C., Lara, Luisa María, Becerril, S., Sánchez Carrasco, Miguel Andrés, Moreno-Raya, M.E., Xu, W., Strachan, J. B. P., Bauer, Florian Franz, Schäfer, S., Seifert, W., Grözinger, U., Perger, M., Hatzes, Artie P., Benítez, D., Nortmann, L., Rodríguez Trinidad, A., Hernández Castaño, L., Lamert, A., Nowak, G., Ofir, A., Oreiro, Raquel, Tulloch, S.M., Maroto Fernández, D., Pallé, Enric, Hermelo, I., Vico Linares, J.I., Arroyo-Torres, B., Tabernero, H. M., Pluto, M., Lafarga, M., Dreizler, S., Huber, A., Rabaza, O., Ramón, A., Berdiñas, Z. M., Brinkmöller, M., Antona, R., Pedraz, S., Feiz, C., González-Peinado, R., Sarkis, Paula, Pascual Granado, J., Guenther, E. W., Alonso-Floriano, F. Javier, Colomé, J., Díez-Alonso, E., García-Piquer, A., Mall, U., Rohloff, R.-R., and Galadí-Enriquez, D.
Abstract: The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520¿1710 nm at a resolution of at least R >80 000, and we measure its RV, H¿ emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700¿900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s¿1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3-4 m s-1. © ESO 2018.
Published: 2018

28. The CARMENES search for exoplanets around M dwarfs: HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf

Author: Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Ministry of Science, Research and Art Baden-Württemberg, Comisión Nacional de Investigación Científica y Tecnológica (Chile), German Centre for Air and Space Travel, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Reiners, Ansgar, Ribas, Ignasi, Zechmeister, Mathias, Caballero, J. A., Trifonov, T., Dreizler, S., Morales, Juan Carlos, Tal-Or, L., Lafarga, M., Quirrenbach, Andreas, Benítez, D., Rabaza, O., Ramón, A., Reinhart, S., Rodríguez Martínez, Eloy, Redondo, P., Claret, A., Rodríguez Trinidad, A., Rosich, Albert, Sánchez-Blanco, E., Sánchez Carrasco, Miguel Andrés, Solano, E., Sánchez-López, A., Sanz-Forcada, J., Tabernero, H. M., Suárez, J.C., Cárdenas Vázquez, María Concepción, Vico Linares, J.I., Kaminski, Adrian, Vilardell, Francesc, Zapatero Osorio, María Rosa, Jeffers, Sandra V., Aceituno, Jesús, Béjar, Victor J. S., Hagen, Hans-Jürgen, Guàrdia, J., Guenther, E. W., Passegger, V.M., Montes, D., Schweitzer, Andreas, Abril, Miguel, Seifert, W., Cortés-Contreras, M., Alonso-Floriano, F. Javier, Eiff, M.A.V., Antona, R., Anglada-Escudé, Guillem, Arroyo-Torres, B., Anwand-Heerwart, H., Rodríguez-López, Cristina, Baroch, David, Azzaro, M., Bauer, Florian Franz, Barrado y Navascués, David, Berdiñas, Z. M., Becerril, S., Bergond, G., Blümcke, M., Brinkmöller, M., Del Burgo, C., Cifuentes, C., Cano, J., Casal, E., Lara, Luisa María, Díez-Alonso, E., Ferro, I.M., Colomé, J., Czesla, S., Galadí-Enriquez, D., García-Piquer, A., Gesa, Lluis, López-Puertas, Manuel, Gómez Galera, V., Guijarro, A., González Hernández, Jonay I., González-Peinado, R., Fernández, M., Helmling, J., Gutiérrez-Soto, J., de Guindos, E., Martín-Ruiz, Susana, Hedrosa, R.P., Hermelo, I., Amado, Pedro J., Hernández Arabí, R., Hernández Castaño, L., de Juan, E., Hernández Hernando, F., Herrero, E., Labarga, F., Klutsch, A., López del Fresno, M., Lampón, M., López González, Maria J., López Salas, J.F., López-Santiago, J., Magán Madinabeitia, H., Marfil, E., Marín Molina, J.A., Miralda-Escudé, Jordi, Maroto Fernández, D., Martín, Eduardo Lorenzo, Moreno-Raya, M.E., Nortmann, L., Nowak, G., Moya, A., Oreiro, Raquel, Pallé, Enric, Pascual, J., Pedraz, S., Pérez Medialdea, D., Perger, M., Rebolo López, Rafael, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Ministerio de Economía y Competitividad (España), Ministry of Science, Research and Art Baden-Württemberg, Comisión Nacional de Investigación Científica y Tecnológica (Chile), German Centre for Air and Space Travel, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Reiners, Ansgar, Ribas, Ignasi, Zechmeister, Mathias, Caballero, J. A., Trifonov, T., Dreizler, S., Morales, Juan Carlos, Tal-Or, L., Lafarga, M., Quirrenbach, Andreas, Benítez, D., Rabaza, O., Ramón, A., Reinhart, S., Rodríguez Martínez, Eloy, Redondo, P., Claret, A., Rodríguez Trinidad, A., Rosich, Albert, Sánchez-Blanco, E., Sánchez Carrasco, Miguel Andrés, Solano, E., Sánchez-López, A., Sanz-Forcada, J., Tabernero, H. M., Suárez, J.C., Cárdenas Vázquez, María Concepción, Vico Linares, J.I., Kaminski, Adrian, Vilardell, Francesc, Zapatero Osorio, María Rosa, Jeffers, Sandra V., Aceituno, Jesús, Béjar, Victor J. S., Hagen, Hans-Jürgen, Guàrdia, J., Guenther, E. W., Passegger, V.M., Montes, D., Schweitzer, Andreas, Abril, Miguel, Seifert, W., Cortés-Contreras, M., Alonso-Floriano, F. Javier, Eiff, M.A.V., Antona, R., Anglada-Escudé, Guillem, Arroyo-Torres, B., Anwand-Heerwart, H., Rodríguez-López, Cristina, Baroch, David, Azzaro, M., Bauer, Florian Franz, Barrado y Navascués, David, Berdiñas, Z. M., Becerril, S., Bergond, G., Blümcke, M., Brinkmöller, M., Del Burgo, C., Cifuentes, C., Cano, J., Casal, E., Lara, Luisa María, Díez-Alonso, E., Ferro, I.M., Colomé, J., Czesla, S., Galadí-Enriquez, D., García-Piquer, A., Gesa, Lluis, López-Puertas, Manuel, Gómez Galera, V., Guijarro, A., González Hernández, Jonay I., González-Peinado, R., Fernández, M., Helmling, J., Gutiérrez-Soto, J., de Guindos, E., Martín-Ruiz, Susana, Hedrosa, R.P., Hermelo, I., Amado, Pedro J., Hernández Arabí, R., Hernández Castaño, L., de Juan, E., Hernández Hernando, F., Herrero, E., Labarga, F., Klutsch, A., López del Fresno, M., Lampón, M., López González, Maria J., López Salas, J.F., López-Santiago, J., Magán Madinabeitia, H., Marfil, E., Marín Molina, J.A., Miralda-Escudé, Jordi, Maroto Fernández, D., Martín, Eduardo Lorenzo, Moreno-Raya, M.E., Nortmann, L., Nowak, G., Moya, A., Oreiro, Raquel, Pallé, Enric, Pascual, J., Pedraz, S., Pérez Medialdea, D., Perger, M., and Rebolo López, Rafael
Abstract: We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V = 8.9 mag, M = 0.58 ± 0.08 M), a bright M0.0 V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of K = 5.1 ± 0.4 m s and a period of P = 86.54 ± 0.06 d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass m sin i = 25 ± 2 M, 1.5 times the mass of Neptune, with an orbital semi-major axis a = 0.32 au and low eccentricity (e < 0.13). HD 147379 b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1 d (and its first harmonic), which we attribute to the rotation period of the star.© ESO, 2018.
Published: 2018

29. The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars

Author: Consejo Superior de Investigaciones Científicas (España), European Commission, Max Planck Institute for Astronomy, CSIC - Instituto de Astrofísica de Andalucía (IAA), Landessternwarte Königstuhl, CSIC - Instituto de Ciencias del Espacio (ICE), Institute for Astrophysics in Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg Karl Schwarzschild-Observatorium, Instituto de Astrofísica de Canarias, Hamburg Observatory, CSIC-INTA - Centro de Astrobiología (CAB), Ministerio de Economía y Competitividad (España), German Research Foundation, Klaus Tschira Foundation, Ministry of Science, Research and Art Baden-Württemberg, Junta de Andalucía, Generalitat de Catalunya, Max Planck Society, Baroch, David, Morales, Juan Carlos, Ribas, Ignasi, Tal-Or, L., Zechmeister, Mathias, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Dreizler, S., Lalitha, S., Jeffers, Sandra V., Lafarga, M., Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Díez-Alonso, E., Galadí-Enriquez, D., Guenther, E. W., Hagen, Hans-Jürgen, Henning, Thomas, Herrero, E., Kürster, M., Montes, D., Nagel, Evangelos, Passegger, V.M., Perger, M., Rosich, Albert, Schweitzer, Andreas, Seifert, W., Consejo Superior de Investigaciones Científicas (España), European Commission, Max Planck Institute for Astronomy, CSIC - Instituto de Astrofísica de Andalucía (IAA), Landessternwarte Königstuhl, CSIC - Instituto de Ciencias del Espacio (ICE), Institute for Astrophysics in Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg Karl Schwarzschild-Observatorium, Instituto de Astrofísica de Canarias, Hamburg Observatory, CSIC-INTA - Centro de Astrobiología (CAB), Ministerio de Economía y Competitividad (España), German Research Foundation, Klaus Tschira Foundation, Ministry of Science, Research and Art Baden-Württemberg, Junta de Andalucía, Generalitat de Catalunya, Max Planck Society, Baroch, David, Morales, Juan Carlos, Ribas, Ignasi, Tal-Or, L., Zechmeister, Mathias, Reiners, Ansgar, Caballero, J. A., Quirrenbach, Andreas, Amado, Pedro J., Dreizler, S., Lalitha, S., Jeffers, Sandra V., Lafarga, M., Béjar, Victor J. S., Colomé, J., Cortés-Contreras, M., Díez-Alonso, E., Galadí-Enriquez, D., Guenther, E. W., Hagen, Hans-Jürgen, Henning, Thomas, Herrero, E., Kürster, M., Montes, D., Nagel, Evangelos, Passegger, V.M., Perger, M., Rosich, Albert, Schweitzer, Andreas, and Seifert, W.
Abstract: Context. The CARMENES spectrograph is surveying ∼300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims. Using spectroscopic observations, we determine the orbital and physical properties of nine new double-line spectroscopic binary systems by analysing their radial velocity curves. Methods. We use two-dimensional cross-correlation techniques to derive the radial velocities of the targets, which are then employed to determine the orbital properties. Photometric data from the literature are also analysed to search for possible eclipses and to measure stellar variability, which can yield rotation periods. Results. Out of the 342 stars selected for the CARMENES survey, 9 have been found to be double-line spectroscopic binaries, with periods ranging from 1.13 to ∼8000 days and orbits with eccentricities up to 0.54. We provide empirical orbital properties and minimum masses for the sample of spectroscopic binaries. Absolute masses are also estimated from mass-luminosity calibrations, ranging between ∼0.1 and ∼0.6 M. Conclusions. These new binary systems increase the number of double-line M dwarf binary systems with known orbital parameters by 15%, and they have lower mass ratios on average. © ESO 2018.
Published: 2018

30. The CARMENES search for exoplanets around M dwarfs: A Neptune-mass planet traversing the habitable zone around HD 180617

Author: CSIC - Instituto de Astrofísica de Andalucía (IAA), Landessternwarte Königstuhl, CSIC - Instituto de Ciencias del Espacio (ICE), University of Göttingen, Thüringer Landessternwarte Tautenburg Karl Schwarzschild-Observatorium, Instituto de Astrofísica de Canarias, CSIC-INTA - Centro de Astrobiología (CAB), Ministerio de Economía y Competitividad (España), German Research Foundation, Klaus Tschira Foundation, Ministry of Science, Research and Art Baden-Württemberg, CSIC-Junta de Extremadura - Instituto de Arqueología (IAM), Universidad Complutense de Madrid, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Max Planck Institute for Astronomy, Kaminski, Adrian, Trifonov, T., Caballero, J. A., Quirrenbach, Andreas, Ribas, Ignasi, Reiners, Ansgar, Amado, Pedro J., Zechmeister, Mathias, Dreizler, S., Perger, M., Tal-Or, L., Bonfils, Xavier, Mayor, M., Astudillo-Defru, Nicola, Bauer, Florian Franz, Béjar, Victor J. S., Cifuentes, C., Colomé, J., Cortés-Contreras, M., Delfosse, X., Díez-Alonso, E., Forveille, T., Guenther, E. W., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kürster, M., Lafarga, M., Luque, R., Mandel, H., Montes, D., Morales, Juan Carlos, Passegger, V.M., Pedraz, S., Reffert, S., Sadegi, S., Schweitzer, Andreas, Seifert, W., Stahl, O., Udry, Stephane, CSIC - Instituto de Astrofísica de Andalucía (IAA), Landessternwarte Königstuhl, CSIC - Instituto de Ciencias del Espacio (ICE), University of Göttingen, Thüringer Landessternwarte Tautenburg Karl Schwarzschild-Observatorium, Instituto de Astrofísica de Canarias, CSIC-INTA - Centro de Astrobiología (CAB), Ministerio de Economía y Competitividad (España), German Research Foundation, Klaus Tschira Foundation, Ministry of Science, Research and Art Baden-Württemberg, CSIC-Junta de Extremadura - Instituto de Arqueología (IAM), Universidad Complutense de Madrid, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, Max Planck Institute for Astronomy, Kaminski, Adrian, Trifonov, T., Caballero, J. A., Quirrenbach, Andreas, Ribas, Ignasi, Reiners, Ansgar, Amado, Pedro J., Zechmeister, Mathias, Dreizler, S., Perger, M., Tal-Or, L., Bonfils, Xavier, Mayor, M., Astudillo-Defru, Nicola, Bauer, Florian Franz, Béjar, Victor J. S., Cifuentes, C., Colomé, J., Cortés-Contreras, M., Delfosse, X., Díez-Alonso, E., Forveille, T., Guenther, E. W., Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kürster, M., Lafarga, M., Luque, R., Mandel, H., Montes, D., Morales, Juan Carlos, Passegger, V.M., Pedraz, S., Reffert, S., Sadegi, S., Schweitzer, Andreas, Seifert, W., Stahl, O., and Udry, Stephane
Abstract: Despite their activity, low-mass stars are of particular importance for the search of exoplanets by the means of Doppler spectroscopy, as planets with lower masses become detectable. We report on the discovery of a planetary companion around HD 180617, a bright (J = 5.58 mag), low-mass (M = 0.45M) star of spectral type M2.5 V. The star, located at a distance of 5.9 pc, is the primary of the high proper motion binary system containing vB 10, a star with one of the lowest masses known in most of the twentieth century. Our analysis is based on new radial velocity (RV) measurements made at red-optical wavelengths provided by the high-precision spectrograph CARMENES, which was designed to carry out a survey for Earth-like planets around M dwarfs. The available CARMENES data are augmented by archival Doppler measurements from HIRES and HARPS. Altogether, the RVs span more than 16 yr. The modeling of the RV variations, with a semi-amplitude of K = 2.85-0.25 +0.16 m s-1, yields a Neptune-like planet with a minimum mass of 12.2-1.4 +1.0 M on a 105.90-0.10 +0.09 d circumprimary orbit, which is partly located in the host star's habitable zone. The analysis of time series of common activity indicators does not show any dependence on the detected RV signal. The discovery of HD 180617 b not only adds information to a currently hardly filled region of the mass-period diagram of exoplanets around M dwarfs, but the investigated system becomes the third known binary consisting of M dwarfs and hosting an exoplanet in an S-type configuration. Its proximity makes it an attractive candidate for future studies. © ESO 2018.
Published: 2018

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30 results on '"Passegger, V.M."'

1. The CARMENES search for exoplanets around M dwarfs: A deep transfer learning method to determine Teffand [M/H] of target stars

2. Two temperate earth-mass planets orbiting the nearby star GJ 1002

3. Precise mass determination for the keystone sub-Neptune planet transiting the mid-type M dwarf G 9-40

4. A multi-planetary system orbiting the early-M dwarf TOI-1238

5. Metallicities in M dwarfs: Investigating different determination techniques

6. The CARMENES search for exoplanets around M dwarfs: Two Saturn-mass planets orbiting active stars

7. Precise mass determination for the keystone sub-Neptune planet transiting the mid-type M dwarf G 9-40

8. The CARMENES search for exoplanets around M dwarfs. Not-so-fine hyperfine-split vanadium lines in cool star spectra

9. The CARMENES search for exoplanets around M dwarfs: Planet occurrence rates from a subsample of 71 stars

10. The CARMENES search for exoplanets around M dwarfs: Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780

11. CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions

12. The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars

13. The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities

14. The CARMENES search for exoplanets around M dwarfs: Three temperate-to-warm super-Earths

15. The CARMENES search for exoplanets around M dwarfs: Rubidium abundances in nearby cool stars

16. The CARMENES search for exoplanets around M dwarfs: A deep learning approach to determine fundamental parameters of target stars

17. The CARMENES search for exoplanets around M dwarfs. Convective shift and starspot constraints from chromatic radial velocities

18. A He I upper atmosphere around the warm Neptune GJ 3470 b

19. The CARMENES search for exoplanets around M dwarfs: different roads to radii and masses of the target stars

20. The CARMENES search for exoplanets around M dwarfs. Different roads to radii and masses of the target stars

21. The CARMENES search for exoplanets around M dwarfs: Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital parameters of a super-Earth around GJ 686 (BD+18 3421)

22. The CARMENES search for exoplanets around M dwarfs: The enigmatic planetary system GJ 4276: One eccentric planet or two planets in a 2:1 resonance

23. The CARMENES search for exoplanets around M dwarfs. High-resolution optical and near-infrared spectroscopy of 324 survey stars

24. CARMENES: high-resolution spectra and precise radial velocities in the red and infrared

25. The CARMENES search for exoplanets around M dwarfs Photospheric parameters of target stars from high-resolution spectroscopy

26. The CARMENES search for exoplanets around M dwarfs: The warm super-Earths in twin orbits around the mid-type M dwarfs Ross 1020 (GJ 3779) and LP 819-052 (GJ 1265)

27. The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars

28. The CARMENES search for exoplanets around M dwarfs: HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf

29. The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars

30. The CARMENES search for exoplanets around M dwarfs: A Neptune-mass planet traversing the habitable zone around HD 180617

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