45 results on '"Pamela Arriagada"'
Search Results
2. Stellar activity analysis of Barnard's Star: very slow rotation and evidence for long-term activity cycle
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Ignasi Ribas, B. Toledo-Padrón, Jeffrey D. Crane, F. J. Aceituno, Steven S. Vogt, Jennifer Burt, Franz-Josef Hambsch, J. I. González Hernández, Steve Rau, Y. Ogmen, Susana Martín-Ruiz, B. Harris, I. Cervini, E. N. Johnson, S. Vanaverbeke, Jesús Aceituno, S. Shectman, L. Pérez, Manuel Perger, Bradford P. Holden, A. Suárez Mascareño, Rafael Rebolo, Enric Palle, Matias Diaz, Pamela Arriagada, Cristina Rodríguez-López, Víctor J. S. Béjar, Alfredo Sota, E. Rodriguez, J. L. Ortiz, John Briol, D. Montes, Marcin Kiraga, Scott G. Engle, Nicolás Morales, E. Díez Alonso, E. F. Guinan, S. V. Jeffers, F. S. Urquijo, Ansgar Reiners, Franky Dubois, M. McNeely, Johanna Teske, L. Barbieri, V. Casanova, Cliff Kotnik, Ludwig Logie, Pedro J. Amado, Juan Carlos Morales, Andreas Quirrenbach, Mikko Tuomi, J. B. P. Strachan, Jose A. Caballero, Guillem Anglada-Escudé, Javier Suso López, R. P. Butler, M. Deldem, E. Herrero, D. Rodríguez, M. J. López-González, Felipe Murgas, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Swiss National Science Foundation, Ministerio de Economía y Competitividad (España), La Caixa, Generalitat de Catalunya, and Science and Technology Facilities Council (UK)
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Rotation period ,Astrofísica ,individual: barnard's star (gl 699) [stars] ,FOS: Physical sciences ,Astrophysics ,Star (graph theory) ,Rotation ,01 natural sciences ,law.invention ,Telescope ,Planet ,law ,stars: rotation ,0103 physical sciences ,stars: activity ,Spectroscopy ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,stars: individual: barnard's star (gl 699) ,activity [stars] ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Radial velocity ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,rotation [stars] ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The search for Earth-like planets around late-type stars using ultrastable spectrographs requires a very precise characterization of the stellar activity and the magnetic cycle of the star, since these phenomena induce radial velocity (RV) signals that can be misinterpreted as planetary signals. Among the nearby stars, we have selected Barnard's Star (Gl 699) to carry out a characterization of these phenomena using a set of spectroscopic data that covers about 14.5yr and comes from seven different spectrographs: HARPS, HARPS-N, CARMENES, HIRES, UVES, APF, and PFS; and a set of photometric data that covers about 15.1yr and comes from four different photometric sources: ASAS, FCAPT-RCT, AAVSO, and SNO. We have measured different chromospheric activity indicators (H alpha, CaiiHK, and Nai D), as well as the full width at half-maximum (FWHM), of the cross-correlation function computed for a sub-set of the spectroscopic data. The analysis of generalized Lomb-Scargle periodograms of the time series of different activity indicators reveals that the rotation period of the star is 145 +/- 15d, consistent with the expected rotation period according to the low activity level of the star and previous claims. The upper limit of the predicted activity-induced RV signal corresponding to this rotation period is about 1ms(-1). We also find evidence of a long-term cycle of 10 +/- 2yr that is consistent with previous estimates of magnetic cycles from photometric time series in other M stars of similar activity levels. The available photometric data of the star also support the detection of both the long-term and the rotation signals.© 2019 The Author(s).Published by Oxford University Press on behalf of the Royal Astronomical Society, This work has been financed by the Spanish Ministry of Science, Innovation and Universities (MICIU) through the grant AYA2017-86389-P. BTP acknowledges Fundacion La Caixa for the financial support received in the form of a Ph.D. contract. JIGH acknowledges financial support from the Spanish MICIU under the 2013 Ramon y Cajal program MICIU RYC-2013-14875. ASM acknowledges financial support from the Swiss National Science Foundation (SNSF). The IAA-CSIC and UCM teams acknowledge support by the Spanish Ministry of Economy and Competitiveness (MINECO) through grants AYA2016-79425-C3-1-P, AYA2016-79425-C3-2-P, AYA2016-79425-C3-3-P, ESP2014-54362P, and ESP2017-87143R. IR, JCM, MP, and EHacknowledge support from the Spanish MINECO and the Fondo Europeo de Desarrollo Regional (FEDER) through grant ESP2016-80435-C2-1-R, as well as the support of the Generalitat de Catalunya/CERCA program. GAE research is funded via the STFC Consolidated Grants ST/P000592/1, and a Perren foundation grant. The results of this paper were based on observations made with the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the INAF-Fundacion Galileo Galilei at the Roque de Los Muchachos Observatory of the Instituto de Astrofisica de Canarias (IAC); observations made with the HARPS instrument on the ESO 3.6 m telescope at La Silla Observatory (Chile); observations made with the CARMENES instrument at the 3.5 m telescope of the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain), funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union, and the CARMENES Consortium members. This paper made use of the IAC Supercomputing facility HTCondor (http://research.cs.wisc.edu/htcondor/), partly financed by the Ministry of Economy and Competitiveness with FEDER funds, code IACA13-3E-2493. We are grateful to all the observers of the projects whose data we are using for the following spectrographs: HARPS (072.C-0488, 183.C-0437, 191.C-0505, 099.C-0880), HARPS-N (CAT14A_43, A27CAT_83, CAT13B_136, CAT16A_109, CAT17A_38, CAT17A_58), CARMENES (CARMENES GTO survey), HIRES (U11H, U11H, N12H, N10H, A264Hr, A288Hr, C168Hr, C199Hr, C205Hr, C202Hr, C232Hr, C240Hr, C275Hr, C332Hr, H174Hr, H218Hr, H238Hr, H224Hr, H244Hr, H257Hr, K01H, N007Hr, N014Hr, N024, N054Hr, N05H, N06H, N085Hr, N086Hr, N095Hr, N108Hr, N10H, N112Hr, N118Hr, N125Hr, N129HR, N12H, N12H, N131Hr, N131Hr, N136Hr, N141Hr, N145Hr, N148Hr, N14H, N157Hr, N15H, N168Hr, N19H, N20H, N22H, N28H, N32H, N50H, N59H, U014Hr, U01H, U023Hr, U027Hr, U027Hr, U030Hr, U052Hr, U058Hr, U05H, U064Hr, U077Hr, U078Hr, U07H, U082Hr, U084Hr, U08H, U10H, U115Hr, U11H, U12H, U131Hr, U142Hr, U66H, Y013Hr, Y065Hr, Y283Hr, Y292Hr), UVES (65.L-0428, 66.C-0446, 267.C-5700, 68.C0415, 69.C-0722, 70.C-0044, 71.C-0498, 072.C0495, 173.C-0606, 078.C-0829), APF (LCES/APF planet survey), and PFS (Carnegie-California survey).
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- 2019
3. The test case of HD26965: difficulties disentangling weak Doppler signals from stellar activity
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Stephen A. Shectman, Pamela Arriagada, Steven S. Vogt, James S. Jenkins, Mikko Tuomi, Ian B. Thompson, Jeffrey D. Crane, Fabo Feng, R. Paul Butler, Johanna Teske, M. Soto, and Matías R. Díaz
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Test (assessment) ,Methods statistical ,symbols.namesake ,Space and Planetary Science ,0103 physical sciences ,symbols ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Doppler effect ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD26965, with an orbital period of 42.364$\pm$0.015 days, or alternatively, as the presence of residual, uncorrected rotational activity in the data. Observations include data from HIRES, PFS, CHIRON, and HARPS, where 1,111 measurements were made over 16 years. Our best solution for HD26965 $b$ is consistent with a super-Earth that has a minimum mass of 6.92$\pm$0.79 M$_{\oplus}$ orbiting at a distance of 0.215$\pm$0.008 AU from its host star. We have analyzed the correlation between spectral activity indicators and the radial velocities from each instrument, showing moderate correlations that we include in our model. From this analysis, we recover a $\sim$38 day signal, which matches some literature values of the stellar rotation period. However, from independent Mt. Wilson HK data for this star, we find evidence for a significant 42 day signal after subtraction of longer period magnetic cycles, casting doubt on the planetary hypothesis for this period. Although our statistical model strongly suggests that the 42-day signal is Doppler in origin, we conclude that the residual effects of stellar rotation are difficult to fully model and remove from this dataset, highlighting the difficulties to disentangle small planetary signals and photospheric noise, particularly when the orbital periods are close to the rotation period of the star. This study serves as an excellent test case for future works that aim to detect small planets orbiting `Sun-like' stars using radial velocity measurements., Comment: 16 pages, 10 figures, 13 tables, accepted for publication in AJ
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- 2018
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4. HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short Period Transiting Giant Planets in the Neptune-Jupiter Mass Range
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Th. Henning, Kaloyan Penev, Joel D. Hartman, Z. Csubry, David J. Osip, George Zhou, Vincent Suc, Paula Sarkis, M. de Val-Borro, Ian B. Thompson, Rafael Brahm, Paul Butler, S. Ciceri, Markus Rabus, Gáspár Á. Bakos, P. Sári, Andrés Jordán, Néstor Espinoza, Johanna Teske, Pamela Arriagada, I. Papp, Luigi Mancini, S. Shectman, Daniel Bayliss, J. Bento, Jeffrey D. Crane, Matías R. Díaz, J. Lazar, Waqas Bhatti, and Brian P. Schmidt
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010504 meteorology & atmospheric sciences ,Library science ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,7. Clean energy ,law.invention ,Telescope ,Settore FIS/05 - Astronomia e Astrofisica ,law ,Neptune ,Observatory ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Astronomy and Astrophysics ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Christian ministry ,Astrophysics::Earth and Planetary Astrophysics ,Partial support ,Jupiter mass ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery of four short period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 M$_J$, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets range from 2.7d to 4.7d, with HATS-43b having an orbit that appears to be marginally non-circular (e= 0.173$\pm$0.089). HATS-44 is notable for a high metallicity ([Fe/H]= 0.320$\pm$0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3, Comment: 23 pages, 10 figures, submitted
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- 2017
5. New planetary systems from the Calan–Hertfordshire Extrasolar Planet Search
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Dante Minniti, J. P. Cordero, Yakiv V. Pavlenko, Felipe Murgas, M. I. Jones, N. Becerra Yoma, Blake Pantoja, Matías R. Díaz, Mercedes Lopez-Morales, O. Ivanyuk, Pamela Arriagada, Mikko Tuomi, D. J. Pinfield, Patricio Rojo, A. Aguayo, James S. Jenkins, M. Soto, Rafael Brahm, John R. Barnes, Rodrigo Mahu, Maria-Teresa Ruiz, R. P. Butler, Hugh R. A. Jones, Avril C. Day-Jones, and S. Shectman
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010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,solar-type [Stars] ,Kepler-47 ,Planet ,low-mass [Stars] ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Planetary migration ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Astronomy ,Astronomy and Astrophysics ,Planetary system ,Exoplanet ,Planetary systems ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Terrestrial planet ,Astrophysics::Earth and Planetary Astrophysics ,Planetary mass ,Jupiter mass ,formation [Planets and satellites] ,activity [Stars] ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery of eight new giant planets, and updated orbits for four known planets, orbiting dwarf and subgiant stars using the CORALIE, HARPS, and MIKE instruments as part of the Calan-Hertfordshire Extrasolar Planet Search. The planets have masses in the range 1.1-5.4MJs, orbital periods from 40-2900 days, and eccentricities from 0.0-0.6. They include a double-planet system orbiting the most massive star in our sample (HD147873), two eccentric giant planets (HD128356b and HD154672b), and a rare 14 Herculis analogue (HD224538b). We highlight some population correlations from the sample of radial velocity detected planets orbiting nearby stars, including the mass function exponential distribution, confirmation of the growing body of evidence that low-mass planets tend to be found orbiting more metal-poor stars than giant planets, and a possible period-metallicity correlation for planets with masses >0.1MJ, based on a metallicity difference of 0.16 dex between the population of planets with orbital periods less than 100 days and those with orbital periods greater than 100 days., 30 pages, 27 figures, 13 tables. Accepted in MNRAS, 2016 October 28
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- 2017
6. The LCES HIRES/Keck Precision Radial Velocity Exoplanet Survey
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Jennifer Burt, Matías R. Díaz, Eugenio J. Rivera, Mikko Tuomi, Sandy Keiser, Johanna Teske, Steven S. Vogt, Gregory Laughlin, Pamela Arriagada, R. Paul Butler, and Brad Holden
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Minimum mass ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Planetary system ,Orbital period ,01 natural sciences ,Exoplanet ,Radial velocity ,Stars ,Space and Planetary Science ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Main sequence ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We describe a 20-year survey carried out by the Lick-Carnegie Exoplanet Survey Team (LCES), using precision radial velocities from HIRES on the Keck-I telescope to find and characterize extrasolar planetary systems orbiting nearby F, G, K, and M dwarf stars. We provide here 60,949 precision radial velocities for 1,624 stars contained in that survey. We tabulate a list of 357 significant periodic signals that are of constant period and phase, and not coincident in period and/or phase with stellar activity indices. These signals are thus strongly suggestive of barycentric reflex motion of the star induced by one or more candidate exoplanets in Keplerian motion about the host star. Of these signals, 225 have already been published as planet claims, 60 are classified as significant unpublished planet candidates that await photometric follow-up to rule out activity-related causes, and 54 are also unpublished, but are classified as "significant" signals that require confirmation by additional data before rising to classification as planet candidates. Of particular interest is our detection of a candidate planet with a minimum mass of 3.9 Earth masses and an orbital period of 9.9 days orbiting Lalande 21185, the fourth-closest main sequence star to the Sun. For each of our exoplanetary candidate signals, we provide the period and semi-amplitude of the Keplerian orbital fit, and a likelihood ratio estimate of its statistical significance. We also tabulate 18 Keplerian-like signals that we classify as likely arising from stellar activity., Accepted for publication in The Astronomical Journal. Paper data available at: http://home.dtm.ciw.edu/ebps/data/
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- 2017
7. The Discovery and Mass Measurement of a New Ultra-short-period Planet: K2-131b
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Fei Dai, Joshua N. Winn, Davide Gandolfi, Sharon X. Wang, Johanna K. Teske, Jennifer Burt, Simon Albrecht, Oscar Barragán, William D. Cochran, Michael Endl, Malcolm Fridlund, Artie P. Hatzes, Teruyuki Hirano, Lea A. Hirsch, Marshall C. Johnson, Anders Bo Justesen, John Livingston, Carina M. Persson, Jorge Prieto-Arranz, Andrew Vanderburg, Roi Alonso, Giuliano Antoniciello, Pamela Arriagada, R. P. Butler, Juan Cabrera, Jeffrey D. Crane, Felice Cusano, Szilárd Csizmadia, Hans Deeg, Sergio B. Dieterich, Philipp Eigmüller, Anders Erikson, Mark E. Everett, Akihiko Fukui, Sascha Grziwa, Eike W. Guenther, Gregory W. Henry, Steve B. Howell, John Asher Johnson, Judith Korth, Masayuki Kuzuhara, Norio Narita, David Nespral, Grzegorz Nowak, Enric Palle, Martin Pätzold, Heike Rauer, Pilar Montañés Rodríguez, Stephen A. Shectman, Alexis M. S. Smith, Ian B. Thompson, Vincent Van Eylen, Michael W. Williamson, Robert A. Wittenmyer, USA, GBR, FRA, and DEU
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Physics ,010504 meteorology & atmospheric sciences ,individual (EPIC 228732031) ,planetary systems - stars ,Astronomy and Astrophysics ,Space and Planetary Science ,Astrophysics ,EPIC ,Keywords: planetary systems — planets and satellites — stars: individual (EPIC 228732031) ,01 natural sciences ,Mass measurement ,Radial velocity ,Planet ,0103 physical sciences ,Orbital motion ,010303 astronomy & astrophysics ,Planetary mass ,0105 earth and related environmental sciences - Abstract
We report the discovery of a new ultra-short-period planet and summarize the properties of all such planets for which the mass and radius have been measured. The new planet, K2-131b, was discovered in K2 Campaign 10. It has a radius of 1.81-0.12+0.16 R\oplus and orbits a G dwarf with a period of 8.9 hr. Radial velocities obtained with Magellan/PFS and TNG/HARPS-N show evidence for stellar activity along with orbital motion. We determined the planetary mass using two different methods: (1) the "floating chunk offset" method, based only on changes in velocity observed on the same night; and (2) a Gaussian process regression based on both the radial velocity and photometric time series. The results are consistent and lead to a mass measurement of 6.5± 1.6 M\oplus and a mean density of 6.0-2.7+3.0 g cm-3.
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- 2017
8. HATS-60b–HATS-69b: 10 Transiting Planets from HATSouth
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P. Sári, Andrés Jordán, I. Papp, Th. Henning, S. Shectman, J. Lázár, C. G. Tinney, Vincent Suc, Waqas Bhatti, J. Bento, R. P. Butler, Néstor Espinoza, Pamela Arriagada, Kaloyan Penev, Joel D. Hartman, I. Thompson, S. Durkan, Daniel Bayliss, Paula Sarkis, Gáspár Á. Bakos, Z. Csubry, Rafael Brahm, Markus Rabus, M. de Val-Borro, Duncan J. Wright, Luigi Mancini, B. Addison, J. Crane, Thiam-Guan Tan, and George Zhou
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Physics ,010504 meteorology & atmospheric sciences ,Astronomy ,Astronomy and Astrophysics ,Radius ,01 natural sciences ,Exoplanet ,Jupiter ,techniques: photometric ,Stars ,Photometry (astronomy) ,Settore FIS/05 - Astronomia e Astrofisica ,Space and Planetary Science ,Planet ,Saturn ,0103 physical sciences ,Binary star ,Astrophysics::Earth and Planetary Astrophysics ,stars: individual ,010303 astronomy & astrophysics ,techniques: spectroscopic ,0105 earth and related environmental sciences - Abstract
We report the discovery of 10 transiting extrasolar planets by the HATSouth survey. The planets range in mass from the super-Neptune HATS- 62b, with {M}p< 0.179 {M}{{J}}, to the super- Jupiter HATS-66b, with {M}p=5.33 {M}{{J}}, and in size from the Saturn HATS-69b, with {R}p=0.94 {R}{{J}}, to the inflated Jupiter HATS-67b, with {R}p=1.69 {R}{{J}}. The planets have orbital periods between 1.6092 days (HATS-67b) and 7.8180 days (HATS-61b). The hosts are dwarf stars with masses ranging from 0.89 {M}‚òâ (HATS-69) to 1.56 {M}‚òâ (HATS-64) and have apparent magnitudes between V=12.276+/- 0.020 mag (HATS-68) and V=14.095+/- 0.030 mag (HATS-66). The super-Neptune HATS-62b is the least massive planet discovered to date with a radius larger than Jupiter. Based largely on the Gaia DR2 distances and broadband photometry, we identify three systems (HATS-62, HATS-64, and HATS-65) as having possible unresolved binary star companions. We discuss in detail our methods for incorporating the Gaia DR2 observations into our modeling of the system parameters and into our blend analysis procedures. The HATSouth network is operated by a collaboration consisting of Princeton University (PU), the Max Planck Institute für Astronomie (MPIA), the Australian National University (ANU), and the Pontificia Universidad Católica de Chile (PUC). The station at Las Campanas Observatory (LCO) of the Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. Based in part on observations made with the MPG 2.2 m Telescope at the ESO Observatory in La Silla. Based on observations collected at the European Southern Observatory under ESO programs 094.C-0428(A), 095.C-0367(A), 097.C-0571(A), 098.C-0292(A), 099.C-0374(A), 0100.C-0406(A), and 0100.C-0406(B). This paper includes data gathered with the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile. Based in part on observations made with the Anglo- Australian Telescope operated by the Australian Astronomical Observatory.
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- 2019
9. The Magellan PFS Planet Search Program: Radial Velocity and Stellar Abundance Analyses of the 360 AU, Metal-Poor Binary 'Twins' HD 133131A & B
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Steve Vogt, Johanna Teske, Stephen A. Shectman, Ian B. Thompson, Matías R. Díaz, R. Paul Butler, Pamela Arriagada, and Jeffrey D. Crane
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Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,010504 meteorology & atmospheric sciences ,Star (game theory) ,Metallicity ,FOS: Physical sciences ,Minimum mass ,Astronomy and Astrophysics ,Astrophysics ,Planetary system ,01 natural sciences ,Exoplanet ,Radial velocity ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Planet ,0103 physical sciences ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present a new precision radial velocity (RV) dataset that reveals multiple planets orbiting the stars in the $\sim$360 AU, G2$+$G2 "twin" binary HD 133131AB. Our 6 years of high-resolution echelle observations from MIKE and 5 years from PFS on the Magellan telescopes indicate the presence of two eccentric planets around HD 133131A with minimum masses of 1.43$\pm$0.03 and 0.63$\pm$0.15 $\mathcal{M}_{\rm J}$ at 1.44$\pm$0.005 and 4.79$\pm$0.92 AU, respectively. Additional PFS observations of HD 133131B spanning 5 years indicate the presence of one eccentric planet of minimum mass 2.50$\pm$0.05 $\mathcal{M}_{\rm J}$ at 6.40$\pm$0.59 AU, making it one of the longest period planets detected with RV to date. These planets are the first to be reported primarily based on data taken with PFS on Magellan, demonstrating the instrument's precision and the advantage of long-baseline RV observations. We perform a differential analysis between the Sun and each star, and between the stars themselves, to derive stellar parameters and measure a suite of 21 abundances across a wide range of condensation temperatures. The host stars are old (likely $\sim$9.5 Gyr) and metal-poor ([Fe/H]$\sim$-0.30), and we detect a $\sim$0.03 dex depletion in refractory elements in HD 133131A versus B (with standard errors $\sim$0.017). This detection and analysis adds to a small but growing sample of binary "twin" exoplanet host stars with precise abundances measured, and represents the most metal-poor and likely oldest in that sample. Overall, the planets around HD 133131A and B fall in an unexpected regime in planet mass-host star metallicity space and will serve as an important benchmark for the study of long period giant planets., Accepted by AJ August 22, 2016, 33 pages
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- 2016
10. State of the Field: Extreme Precision Radial Velocities
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Scott A. Diddams, David W. Hogg, Robert A. Wittenmyer, John Asher Johnson, Lars A. Buchhave, Greg Laughlin, Gábor Fűrész, Jeff A. Valenti, Nuno C. Santos, Damien Ségransan, Pamela Arriagada, Debra A. Fischer, François Bouchy, Frank Grundahl, Tilo Steinmetz, Artie P. Hatzes, Xavier Dumusque, B. Scott Gaudi, Roman V. Baluev, Peter Plavchan, Francesco Pepe, Andrew Szentgyorgyi, T. M. McCracken, Paul Fournier, Pedro Figueira, Daniel Foreman-Mackey, Suvrath Mahadevan, Lisa Prato, Alessandro Sozzetti, David Sawyer, Mario R. Perez, Eric B. Ford, Enrique Herrero, Paul Robertson, David W. Latham, Stéphane Udry, Jason D. Eastman, David F. Phillips, Guillem Anglada-Escudé, Ansgar Reiners, Jason T. Wright, Andrew W. Howard, Sharon X. Wang, Guillaume Hébrard, Thomas J. Loredo, Christophe Lovis, C. Jurgenson, P. C. Gregory, T. A. Carroll, Michael Endl, Justin R. Crepp, Abhijit Chakraborty, Andreas Quirrenbach, Paul Jorden, Rebekah I. Dawson, Jacob L. Bean, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), McDonald Observatory, University of Texas at Austin [Austin], Danish AsteroSeismology Centre (DASC), Aarhus University [Aarhus], Thüringer Landessternwarte Tautenburg (TLS), Departament de Ciències Mèdiques Bàsiques, University of Lleida-IRBLLEIDA-PCiTA, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Landessternwarte Königstuhl [ZAH] (LSW), Universität Heidelberg [Heidelberg], Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Department für Physik der Ludwig Maximilians Universität (LMU), Ludwig-Maximilians-Universität München (LMU), Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, University of New South Wales [Sydney] (UNSW), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Universität Heidelberg [Heidelberg] = Heidelberg University, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
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FOS: Physical sciences ,01 natural sciences ,010309 optics ,symbols.namesake ,Planet ,0103 physical sciences ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Spectrograph ,Remote sensing ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Spectrometer ,Detector ,Bandwidth (signal processing) ,Astronomy and Astrophysics ,Exoplanet ,3. Good health ,Radial velocity ,13. Climate action ,Space and Planetary Science ,symbols ,Astrophysics::Earth and Planetary Astrophysics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - Instrumentation and Methods for Astrophysics ,Doppler effect ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of the art Doppler precision and identified the critical path challenges for reaching 10 cm/s measurement precision. The presentations and discussion of key issues for instrumentation and data analysis and the workshop recommendations for achieving this precision are summarized here. Beginning with the HARPS spectrograph, technological advances for precision radial velocity measurements have focused on building extremely stable instruments. To reach still higher precision, future spectrometers will need to produce even higher fidelity spectra. This should be possible with improved environmental control, greater stability in the illumination of the spectrometer optics, better detectors, more precise wavelength calibration, and broader bandwidth spectra. Key data analysis challenges for the precision radial velocity community include distinguishing center of mass Keplerian motion from photospheric velocities, and the proper treatment of telluric contamination. Success here is coupled to the instrument design, but also requires the implementation of robust statistical and modeling techniques. Center of mass velocities produce Doppler shifts that affect every line identically, while photospheric velocities produce line profile asymmetries with wavelength and temporal dependencies that are different from Keplerian signals. Exoplanets are an important subfield of astronomy and there has been an impressive rate of discovery over the past two decades. Higher precision radial velocity measurements are required to serve as a discovery technique for potentially habitable worlds and to characterize detections from transit missions. The future of exoplanet science has very different trajectories depending on the precision that can ultimately be achieved with Doppler measurements., Comment: 45 pages, 23 Figures, workshop summary proceedings
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- 2016
11. Doppler Monitoring of five K2 Transiting Planetary Systems
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Norio Narita, Johanna Teske, Amanda Kiilerich, Roberto Sanchis-Ojeda, Ignasi Ribas, Pamela Arriagada, Ian B. Thompson, Stephen A. Shectman, R. Paul Butler, Allyson Bieryla, Robert A. Wittenmyer, Andrew Vanderburg, Enric Palle, Leslie A. Rogers, Joshua N. Winn, David W. Latham, Fei Dai, Teruyuki Hirano, Vincent Van Eylen, Simon Albrecht, Liang Yu, Jeffrey D. Crane, Grzegorz Nowak, and John Asher Johnson
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Stellar rotation ,FOS: Physical sciences ,Astronomy and Astrophysics ,Radius ,Astrophysics ,Planetary system ,Orbital period ,01 natural sciences ,symbols.namesake ,Stars ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,symbols ,010303 astronomy & astrophysics ,Doppler effect ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
In an effort to measure the masses of planets discovered by the NASA {\it K2} mission, we have conducted precise Doppler observations of five stars with transiting planets. We present the results of a joint analysis of these new data and previously published Doppler data. The first star, an M dwarf known as K2-3 or EPIC~201367065, has three transiting planets ("b", with radius $2.1~R_{\oplus}$; "c", $1.7~R_{\oplus}$; and "d", $1.5~R_{\oplus}$). Our analysis leads to the mass constraints: $M_{b}=8.1^{+2.0}_{-1.9}~M_{\oplus}$ and $M_{c}$ < $ 4.2~M_{\oplus}$~(95\%~conf.). The mass of planet d is poorly constrained because its orbital period is close to the stellar rotation period, making it difficult to disentangle the planetary signal from spurious Doppler shifts due to stellar activity. The second star, a G dwarf known as K2-19 or EPIC~201505350, has two planets ("b", $7.7~R_{\oplus}$; and "c", $4.9~R_{\oplus}$) in a 3:2 mean-motion resonance, as well as a shorter-period planet ("d", $1.1~R_{\oplus}$). We find $M_{b}$= $28.5^{+5.4}_{-5.0} ~M_{\oplus}$, $M_{c}$= $25.6^{+7.1}_{-7.1} ~M_{\oplus}$ and $M_{d}$ < $14.0~M_{\oplus} $~(95\%~conf.). The third star, a G dwarf known as K2-24 or EPIC~203771098, hosts two transiting planets ("b", $5.7~R_{\oplus}$; and "c", $7.8~R_{\oplus}$) with orbital periods in a nearly 2:1 ratio. We find $M_{b}$= $19.8^{+4.5}_{-4.4} ~M_{\oplus}$ and $M_{c}$ = $26.0^{+5.8}_{-6.1}~M_{\oplus}$....., 20 pages, 14 figures, 10 tables. Accepted by ApJ
- Published
- 2016
12. MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112
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Katie M. Morzinski, Pierre Bergeron, Hugh R. A. Jones, Pamela Arriagada, Philip M. Hinz, Jeremy Bailey, James S. Jenkins, Laird M. Close, Amélie Simon, Eric E. Mamajek, Jared R. Males, John H. Debes, Jacqueline K. Faherty, Timothy J. Rodigas, Brad D. Carter, R. Paul Butler, Guillem Anglada-Escudé, Simon J. O'Toole, C. G. Tinney, Alycia J. Weinberger, and Robert A. Wittenmyer
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010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Star (graph theory) ,01 natural sciences ,Primary (astronomy) ,Long period ,individual (HD 11112) [Stars] ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Adaptive optics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,radial velocities [Techniques] ,Binaries ,White dwarfs ,White dwarf ,Astronomy and Astrophysics ,adaptive optics [Instrumentation] ,Radial velocity ,high angular resolution [Techniques] ,Orbit ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Spectral energy distribution ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2\fasec 2 (100 AU) at multiple wavelengths spanning 0.6-4 \microns ~and show that it is most likely a gravitationally-bound cool white dwarf. Modeling its spectral energy distribution (SED) suggests that its mass is 0.9-1.1 \msun, which corresponds to very high-eccentricity, near edge-on orbits from Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is $>2\sigma$ discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years., Comment: Accepted to ApJ on September 8, 2016. 13 pages aastex6 2-column format. Comments welcome
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- 2016
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13. The Lick-Carnegie Exoplanet Survey: HD32963 -- A New Jupiter Analog Orbiting a Sun-like Star
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Pamela Arriagada, Matías R. Díaz, D. M. Rowan, Steven S. Vogt, Russell Hanson, Songhu Wang, R. Paul Butler, S. Keiser, Gregory Laughlin, Stefano Meschiari, Brad Holden, Jennifer Burt, and Johanna Teske
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Gas giant ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Star (graph theory) ,01 natural sciences ,Exoplanet ,Jupiter ,13. Climate action ,Space and Planetary Science ,0103 physical sciences ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present a set of 109 new, high-precision Keck/HIRES radial velocity (RV) observations for the solar-type star HD 32963. Our dataset reveals a candidate planetary signal with a period of 6.49 $\pm$ 0.07 years and a corresponding minimum mass of 0.7 $\pm$ 0.03 Jupiter masses. Given Jupiter's crucial role in shaping the evolution of the early Solar System, we emphasize the importance of long-term radial velocity surveys. Finally, using our complete set of Keck radial velocities and correcting for the relative detectability of synthetic planetary candidates orbiting each of the 1,122 stars in our sample, we estimate the frequency of Jupiter analogs across our survey at approximately 3%., 10 pages, 13 figures. Accepted for publication on the Astrophysical Journal. Full set of radial velocities included
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- 2015
14. HATS-59b,c: A Transiting Hot Jupiter and a Cold Massive Giant Planet around a Sun-like Star
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Waqas Bhatti, Andrés Jordán, Rafael Brahm, Duncan J. Wright, P. Sári, S. Durkan, Pamela Arriagada, Thiam-Guan Tan, George Zhou, C. G. Tinney, J. Lázár, Paula Sarkis, Lars A. Buchhave, Jeffrey D. Crane, M. de Val-Borro, Th. Henning, Luigi Mancini, Istvan Papp, Markus Rabus, Z. Csubry, Brett C. Addison, J. Bento, R. P. Butler, Kaloyan Penev, Joel D. Hartman, Daniel Bayliss, Néstor Espinoza, Vincent Suc, S. Shectman, and Gáspár Á. Bakos
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010504 meteorology & atmospheric sciences ,photometric ,planetary systems ,stars: individual (HATS-59) ,techniques: spectroscopic ,Astronomy and Astrophysics ,Space and Planetary Science ,FOS: Physical sciences ,Orbital eccentricity ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Photometric ,01 natural sciences ,spectroscopic [Techniques] ,Settore FIS/05 - Astronomia e Astrofisica ,Planet ,0103 physical sciences ,Hot Jupiter ,Astrophysics::Solar and Stellar Astrophysics ,Circular orbit ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Planetary migration ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,individual (HATS-59) [Stars] ,Astrophysics::Instrumentation and Methods for Astrophysics ,Giant planet ,Astronomy ,Planetary system ,Radial velocity ,Planetary systems ,13. Climate action ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the first discovery of a multi-planetary system by the HATSouth network, HATS-59b,c, a planetary system with an inner transiting hot Jupiter and an outer cold massive giant planet, which was detected via radial velocity. The inner transiting planet, HATS-59b, is on an eccentric orbit with $e = 0.129\pm0.049$, orbiting a $V=13.951\pm0.030$ mag solar-like star ($M_* = 1.038\pm0.039 M_{\odot}$, and $R_* = 1.036\pm0.067 R_{\odot}$) with a period of $5.416077\pm0.000017$ days. The outer companion, HATS-59c is on a circular orbit with $ m \sin i = 12.8\pm1.1 M_\mathrm{J}$, and a period of $1422\pm14$ days. The inner planet has a mass of $0.806\pm0.069 M_\mathrm{J}$ and a radius of $1.126\pm0.077 M_\mathrm{J}$, yielding a density of $0.70\pm0.16 {\rm g\,cm^{-3}}$. Unlike most of the planetary systems that include only a single hot Jupiter, HATS-59b,c includes, in addition to the transiting hot Jupiter, a massive outer companion. The architecture of this system is valuable for understanding planet migration., Comment: 12 pages, 9 figures, submitted to AJ. For a short discussion, see https://sites.google.com/view/paulasarkis/research/hats-59
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- 2018
15. K2-106, a system containing a metal-rich planet and a planet of lower density
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David Nespral, Ph. Eigmüller, Alexis M. S. Smith, Eike W. Guenther, Davide Gandolfi, Pamela Arriagada, Heike Rauer, R. P. Butler, S. Sabotta, Martin Pätzold, Jeffrey D. Crane, Bun'ei Sato, A. Chau, Robert A. Wittenmyer, S. Shectman, A. P. Hatzes, Grzegorz Nowak, Teruyuki Hirano, Enric Palle, Carina M. Persson, Judith Korth, Ravit Helled, Jennifer Burt, Juan Cabrera, Fei Dai, Andrew Vanderburg, G. Antoniciello, Oscar Barragán, M. Hjorth, Anders Erikson, Malcolm Fridlund, John Asher Johnson, Norio Narita, Luca Fossati, V. Van Eylen, Sz. Csizmadia, Jorge Prieto-Arranz, Sascha Grziwa, Johanna Teske, D. Kubyshkina, Amanda Kiilerich, Ian B. Thompson, Hans J. Deeg, William D. Cochran, Simon Albrecht, and Joshua N. Winn
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EXOPLANET ,TELESCOPE ,010504 meteorology & atmospheric sciences ,Period (periodic table) ,SHORT-PERIOD PLANETS ,Planetary systems ,Stars: Abundances ,Stars: individual: TYC 608-458-1 ,Techniques: photometric ,Techniques: Radial velocities ,Astronomy and Astrophysics ,Space and Planetary Science ,FOS: Physical sciences ,Astrophysics ,MASS ,01 natural sciences ,PARAMETERS ,photometric [techniques] ,Atmosphere ,Planet ,0103 physical sciences ,SPECTROGRAPH ,planetary systems ,010303 astronomy & astrophysics ,MISSION ,0105 earth and related environmental sciences ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Range (particle radiation) ,Atmospheric escape ,radial velocities [techniques] ,Radius ,Planetary system ,abundances [stars] ,SUPER-EARTHS ,RADIAL-VELOCITY MEASUREMENTS ,individual: TYC 608-458-1 [stars] ,STARS ,Earth (classical element) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Planets in the mass range from 2 to 15 MEarth are very diverse. Some of them have low densities, while others are very dense. By measuring the masses and radii, the mean densities, structure, and composition of the planets are constrained. These parameters also give us important information about their formation and evolution, and about possible processes for atmospheric loss.We determined the masses, radii, and mean densities for the two transiting planets orbiting K2-106. The inner planet has an ultra-short period of 0.57 days. The period of the outer planet is 13.3 days.Although the two planets have similar masses, their densities are very different. For K2-106b we derive Mb=8.36-0.94+0.96 MEarh, Rb=1.52+/-0.16 REarth, and a high density of 13.1-3.6+5.4 gcm-3. For K2-106c, we find Mc=5.8-3.0+3.3 MEarth, Rc=2.50-0.26+0.27 REarth and a relatively low density of 2.0-1.1+1.6 gcm-3.Since the system contains two planets of almost the same mass, but different distances from the host star, it is an excellent laboratory to study atmospheric escape. In agreement with the theory of atmospheric-loss processes, it is likely that the outer planet has a hydrogen-dominated atmosphere. The mass and radius of the inner planet is in agreement with theoretical models predicting an iron core containing 80+20-30% of its mass. Such a high metal content is surprising, particularly given that the star has an ordinary (solar) metal abundance. We discuss various possible formation scenarios for this unusual planet., 11 pages with 9 figures, accepted by A&A, Sep 8, 2017
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- 2017
16. Doppler Monitoring of the WASP-47 Multiplanet System
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John Asher Johnson, R. Paul Butler, Fei Dai, Jeffrey D. Crane, Andrew Vanderburg, Johanna Teske, Stephen A. Shectman, Ian B. Thompson, Robert A. Wittenmyer, Pamela Arriagada, and Joshua N. Winn
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,business.industry ,FOS: Physical sciences ,Astronomy and Astrophysics ,01 natural sciences ,symbols.namesake ,Space and Planetary Science ,0103 physical sciences ,symbols ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Aerospace engineering ,10. No inequality ,business ,010303 astronomy & astrophysics ,Administration (government) ,Doppler effect ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present precise Doppler observations of WASP-47, a transiting planetary system featuring a hot Jupiter with both inner and outer planetary companions. This system has an unusual architecture and also provides a rare opportunity to measure planet masses in two different ways: the Doppler method, and the analysis of transit-timing variations (TTV). Based on the new Doppler data, obtained with the Planet Finder Spectrograph on the Magellan/Clay 6.5m telescope, the mass of the hot Jupiter is $370 \pm 29~M_{\oplus}$. This is consistent with the previous Doppler determination as well as the TTV determination. For the inner planet WASP-47e, the Doppler data lead to a mass of $12.2\pm 3.7~ M_{\oplus}$, in agreement with the TTV-based upper limit of $, Comment: 6 pages, 3 figures, accepted for ApJL
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- 2015
17. No evidence for activity correlations in the radial velocities of Kapteyn's star
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Julien Morin, Matías R. Díaz, Z. M. Berdiñas, Mikko Tuomi, L. F. Sarmiento, Steven S. Vogt, Stephen A. Shectman, Guillem Anglada-Escudé, S. V. Jeffers, E. Gerlach, Pamela Arriagada, Stefan Dreizler, Cristina Rodríguez-López, Paul Butler, C. J. Marvin, James S. Jenkins, Jeffrey D. Crane, Ansgar Reiners, Mathias Zechmeister, Aviv Ofir, Hugh R. A. Jones, P. J. Amado, Queen Mary University of London (QMUL), University of Hertfordshire, Carnegie Institution of Washington, Queen Mary University London, Universidad de Chile, Weizmann Institute of Science [Rehovot, Israël], Institut für Astrophysik [Göttingen], Georg-August-University [Göttingen], Institut für Planetare Geodäsie [Dresden], Technische Universität Dresden = Dresden University of Technology (TU Dresden), UC Santa Cruz, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Ministerio de Economía y Competitividad (España), German Research Foundation, European Research Council, and Fondos de Desarrollo de la Astronomía Nacional (Chile)
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Rotation period ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Stars: individual (Kapteyn's star) ,FOS: Physical sciences ,Astrophysics ,Star (graph theory) ,01 natural sciences ,symbols.namesake ,Planet ,0103 physical sciences ,techniques: radial velocities ,data analysis [Methods] ,010303 astronomy & astrophysics ,Global optimization ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,planetary systems ,stars: individual: Kapteyn’s star ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,radial velocities [Techniques] ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Orbital period ,individual (Kapteyn's star) [Stars] ,methods: data analysis ,Exoplanet ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,Radial velocity ,Planetary systems ,13. Climate action ,Space and Planetary Science ,symbols ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Doppler effect ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Guillem Anglada-Escude et. al., Stellar activity may induce Doppler variability at the level of a few m s which can then be confused by the Doppler signal of an exoplanet orbiting the star. To first order, linear correlations between radial velocity measurements and activity indices have been proposed to account for any such correlation. The likely presence of two super-Earths orbiting Kapteyn's star was reported in Anglada-Escudé et al., but this claim was recently challenged by Robertson et al., who argued for evidence of a rotation period (143 days) at three times the orbital period of one of the proposed planets (Kapteyn's b, P = 48.6 days) and the existence of strong linear correlations between its Doppler signal and activity data. By re-analyzing the data using global statistics and model comparison, we show that such a claim is incorrect given that (1) the choice of a rotation period at 143 days is unjustified, and (2) the presence of linear correlations is not supported by the data. We conclude that the radial velocity signals of Kapteyn's star remain more simply explained by the presence of two super-Earth candidates orbiting it. We note that analysis of time series of activity indices must be executed with the same care as Doppler time series. We also advocate for the use of global optimization procedures and objective arguments, instead of claims based on residual analyses which are prone to biases and incorrect interpretations.© 2016. The American Astronomical Society. All rights reserved.., We acknowledge AYA2014-54348-C3-1-R by MINECO/Spain and FEDER funds/EU (P.J.A., C.R.-L., and Z.M.B.); FPIBES-2011-049647 MINECO/Spain (Z.M.B.). A.R. acknowledges research funding from ERC Starting Grant 279347 and DFG Grant RE1664/9-2. M.Z. is funded through DFG Grant RE 1664/12-1. J.S.J. acknowledges funding by Fondecyt through grant 1161218 and partial support from CATA-Basal (PB06, Conicyt).
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- 2015
18. A0.24+0.18 M⊙ double-lined eclipsing binary from the HATSouth survey
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Néstor Espinoza, R. P. Butler, Kaloyan Penev, Ian B. Thompson, Joel D. Hartman, Andrés Jordán, Jeffrey D. Crane, Vincent Suc, Z. Csubry, Brian P. Schmidt, Gáspár Á. Bakos, Simona Ciceri, Waqas Bhatti, Pamela Arriagada, Rafael Brahm, G. Zhou, Daniel Bayliss, Markus Rabus, S. Shectman, Simon J. Murphy, M. de Val-Borro, Luigi Mancini, Th. Henning, and Robert W. Noyes
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Physics ,Settore FIS/05 - Astronomia e Astrofisica ,Space and Planetary Science ,Binary number ,Astronomy and Astrophysics ,Astrophysics - Published
- 2015
19. A Six-planet System around the Star HD 34445
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Sandy Keiser, Jennifer Burt, Pamela Arriagada, Steven S. Vogt, Mikko Tuomi, Ian B. Thompson, Gregory Laughlin, Johanna Teske, R. Paul Butler, Jeffrey D. Crane, Stephen A. Shectman, Brad Holden, and Matías R. Díaz
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Physics ,Solar System ,Astronomy ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Planetary system ,01 natural sciences ,Exoplanet ,Keplerian motion ,Radial velocity ,010104 statistics & probability ,13. Climate action ,Space and Planetary Science ,Planet ,Observatory ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Great conjunction ,0101 mathematics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present a new precision radial velocity dataset that reveals a multi-planet system orbiting the G0V star HD 34445. Our 18-year span consists of 333 precision radial velocity observations, 56 of which were previously published, and 277 which are new data from Keck Observatory, Magellan at Las Campanas Observatory, and the Automated Planet Finder at Lick Observatory. These data indicate the presence of six planet candidates in Keplerian motion about the host star with periods of 1057, 215, 118, 49, 677, and 5700 days, and minimum masses of 0.63, 0.17, 0.1, 0.05, 0.12 and 0.38 Jupiter masses respectively. The HD 34445 planetary system, with its high degree of multiplicity, its long orbital periods, and its induced stellar radial velocity half-amplitudes in the range $2 \,{\rm m\, s^{-1}} \lesssim K \lesssim 5\,{\rm m\, s^{-1}}$ is fundamentally unlike either our own solar system (in which only Jupiter and Saturn induce significant reflex velocities for the Sun), or the Kepler multiple-transiting systems (which tend to have much more compact orbital configurations), Comment: 10 pages, 11 figures
- Published
- 2017
20. HATS-6b: A Warm Saturn Transiting an Early M Dwarf Star, and a Set of Empirical Relations for Characterizing K and M Dwarf Planet Hosts
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P. Sári, Daniel Bayliss, Ian B. Thompson, S. Ciceri, Néstor Espinoza, M. de Val-Borro, Brian P. Schmidt, Jeffrey D. Crane, Vincent Suc, Luigi Mancini, Gáspár Á. Bakos, Markus Rabus, R. W. Noyes, Pamela Arriagada, Rafael Brahm, Waqas Bhatti, S. Shectman, J. Lázár, Andrés Jordán, Thiam-Guan Tan, George Zhou, Istvan Papp, Th. Henning, R. P. Butler, Kaloyan Penev, Joel D. Hartman, Z. Csubry, and B. Csák
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Earth and Planetary Astrophysics (astro-ph.EP) ,Absolute magnitude ,Physics ,Dwarf star ,Gas giant ,Dwarf planet ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Planetary system ,Stellar classification ,Exoplanet ,Settore FIS/05 - Astronomia e Astrofisica ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Main sequence ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery by the HATSouth survey of HATS-6b, an extrasolar planet transiting a V=15.2 mag, i=13.7 mag M1V star with a mass of 0.57 Msun and a radius of 0.57 Rsun. HATS-6b has a period of P = 3.3253 d, mass of Mp=0.32 Mjup, radius of Rp=1.00 Rjup, and zero-albedo equilibrium temperature of Teq=712.8+-5.1 K. HATS-6 is one of the lowest mass stars known to host a close-in gas giant planet, and its transits are among the deepest of any known transiting planet system. We discuss the follow-up opportunities afforded by this system, noting that despite the faintness of the host star, it is expected to have the highest K-band S/N transmission spectrum among known gas giant planets with Teq < 750 K. In order to characterize the star we present a new set of empirical relations between the density, radius, mass, bolometric magnitude, and V, J, H and K-band bolometric corrections for main sequence stars with M < 0.80 Msun, or spectral types later than K5. These relations are calibrated using eclipsing binary components as well as members of resolved binary systems. We account for intrinsic scatter in the relations in a self-consistent manner. We show that from the transit-based stellar density alone it is possible to measure the mass and radius of a ~0.6 Msun star to ~7% and ~2% precision, respectively. Incorporating additional information, such as the V-K color, or an absolute magnitude, allows the precision to be improved by up to a factor of two., 21 pages, 11 figures, 10 tables. Submitted to AJ. Data available at http://hatsouth.org Code implementing empirical model available at http://www.astro.princeton.edu/~jhartman/kmdwarfparam.html
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- 2014
21. APF - The Lick Observatory Automated Planet Finder
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Jennifer Burt, Jeffrey Lewis, Steven S. Vogt, Eugenio J. Rivera, Sandra M. Faber, Maureen McLean, William Deich, Sandy Keiser, Brad Holden, Tony Misch, Myra Katsuki, John Wareham, Mingzhi Wei, Greg Laughlin, David F. Hilyard, Steve Allen, Lee Laiterman, Dick Kanto, Elinor L. Gates, Mike Saylor, Richard J. Stover, Mike Bolte, Wayne Earthman, Robert I. Kibrick, Kyle Lanclos, Jerry Cabak, Kostas Chloros, Chris Wright, Matthew Thompson, Debra A. Fischer, Michael Peck, Paul Lynam, Matthew Radovan, Geoffrey W. Marcy, Andrew L. Phillips, Joseph S. Miller, David Cowley, James Ward, Chris Lockwood, R. Paul Butler, Brian DuPraw, Barry Alcott, Bernie Walp, Pamela Arriagada, Ken Johnston, Terry Pfister, Dale Sandford, and Harland W. Epps
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Physics ,Photon ,Spectrometer ,business.industry ,FOS: Physical sciences ,Astronomy and Astrophysics ,Exoplanet ,law.invention ,Telescope ,Primary mirror ,Stars ,Optics ,Space and Planetary Science ,law ,Observatory ,Planet ,business ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
The Automated Planet Finder (APF) is a facility purpose-built for the discovery and characterization of extrasolar planets through high-cadence Doppler velocimetry of the reflex barycentric accelerations of their host stars. Located atop Mt. Hamilton, the APF facility consists of a 2.4-m telescope and its Levy spectrometer, an optical echelle spectrometer optimized for precision Doppler velocimetry. APF features a fixed format spectral range from 374 nm - 970 nm, and delivers a "Throughput" (resolution * slit width product) of 114,000 arc-seconds, with spectral resolutions up to 150,000. Overall system efficiency (fraction of photons incident on the primary mirror that are detected by the science CCD) on blaze at 560 nm in planet-hunting mode is 15%. First-light tests on the RV standard stars HD 185144 and HD 9407 demonstrate sub-meter per second precision (RMS per observation) held over a 3-month period. This paper reviews the basic features of the telescope, dome, and spectrometer, and gives a brief summary of first-light performance., Accepted at PASP. Version with full resolution available at http://oklo.org/Vogt_APF_2014.pdf
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- 2014
22. Precision radial velocities of 15 m5-m9 dwarfs
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Hugh R. A. Jones, Mikko Tuomi, Pamela Arriagada, Andrés Jordán, James S. Jenkins, Patricio Rojo, Guillem Anglada-Escudé, Sandra V. Jeffers, Dante Minniti, D. J. Pinfield, and John R. Barnes
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,ta115 ,13. Climate action ,Space and Planetary Science ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Planetary system ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present radial velocity measurements of a sample of M5V-M9V stars from our Red-Optical Planet Survey, ROPS, operating at 0.65-1.025 micron. Radial velocities for 15 stars, with r.m.s. precision down to 2.5 m/s over a week long time scale are achieved using Thorium-Argon reference spectra. We are sensitive to planets with m_psin(i) >= 1.5 MEarth (3 MEarth at 2-sigma) in the classical habitable zone and our observations currently rule out planets with m_psin(i) > 0.5 MJup at 0.03 AU for all our targets. A total of 9 of the 15 targets exhibit r.m.s. < 16 m/s, which enables us to rule out the presence of planets with m_psin(i) > 10 MEarth in 0.03 AU orbits. Since the mean rotation velocity is of order 8 km/s for an M6V star and 15 km/s by M9V, we avoid observing only slow rotators that would introduce a bias towards low axial inclination i << 90 deg systems, which are unfavourable for planet detection. Our targets with the highest vsini values exhibit radial velocities significantly above the photon-noise limited precision, even after accounting for vsini. We therefore monitored stellar activity via chromospheric emission from the Halpha and Ca II infrared triplet lines. A clear trend of log_10(Halpha/Lbol) with radial velocity r.m.s. is seen, implying that significant starspot activity is responsible for the observed radial velocity precision floor. The implication that most late M dwarfs are significantly spotted, and hence exhibit time varying line distortions, indicates that observations to detect orbiting planets need strategies to reliably mitigate against the effects of activity induced radial velocity variations., 30 pages, 9 figures, MNRAS (accepted)
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- 2014
23. GJ 832c: A Super-Earth in the Habitable Zone
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C. G. Tinney, Graeme Salter, Matías R. Díaz, Mikko Tuomi, R. P. Butler, Jeffrey D. Crane, S. A. Schectman, Guillem Anglada-Escudé, Simon J. O'Toole, Robert A. Wittenmyer, Pamela Arriagada, Jonathan P. Marshall, Dante Minniti, James S. Jenkins, Hugh R. A. Jones, Duncan J. Wright, Jeremy Bailey, B. D. Carter, Ian B. Thompson, and Jonathan Horner
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Solar System ,Super-Earth ,Giant planet ,FOS: Physical sciences ,Astronomy and Astrophysics ,Planetary system ,Astrobiology ,Atmosphere ,Jupiter ,Space and Planetary Science ,Planet ,Astrophysics::Earth and Planetary Astrophysics ,Circumstellar habitable zone ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the detection of GJ 832c, a super-Earth orbiting near the inner edge of the habitable zone of GJ 832, an M dwarf previously known to host a Jupiter analog in a nearly-circular 9.4-year orbit. The combination of precise radial-velocity measurements from three telescopes reveals the presence of a planet with a period of 35.68+/-0.03 days and minimum mass (m sin i) of 5.4+/-1.0 Earth masses. GJ 832c moves on a low-eccentricity orbit (e=0.18+/-0.13) towards the inner edge of the habitable zone. However, given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable. Indeed, it is perhaps more likely that GJ 832c is a "super-Venus," featuring significant greenhouse forcing. With an outer giant planet and an interior, potentially rocky planet, the GJ 832 planetary system can be thought of as a miniature version of our own Solar system., Comment: Accepted for publication in ApJ
- Published
- 2014
24. Two planets around Kapteyn's star : a cold and a temperate super-Earth orbiting the nearest halo red-dwarf
- Author
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Hugh R. A. Jones, Mikko Tuomi, Steve Vogt, Guillem Anglada-Escudé, Jeffrey D. Crane, Pedro J. Amado, C. J. Marvin, Ansgar Reiners, Ian B. Thompson, Julien Morin, Matías R. Díaz, Z. M. Berdiñas, Stephen A. Shectman, Mathias Zechmeister, Pamela Arriagada, Stefan Dreizler, Cristina Rodríguez-López, James S. Jenkins, Eugenio J. Rivera, Aviv Ofir, Sandra V. Jeffers, L. F. Sarmiento, R. P. Butler, E. Gerlach, Queen Mary University of London (QMUL), Carnegie Institution of Washington, Universidad de Chile, Institut für Astrophysik [Göttingen], Georg-August-University [Göttingen], Technische Universität Dresden = Dresden University of Technology (TU Dresden), UCO/Lick Observatory, University of California [Santa Cruz] (UCSC), University of California-University of California, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and University of Hertfordshire
- Subjects
Red dwarf ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Planet ,techniques: radial velocities ,Astrophysics::Solar and Stellar Astrophysics ,10. No inequality ,planetary systems ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,stars: individual: Kapteyn’s star ,Astrophysics::Galaxy Astrophysics ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Planetary habitability ,Astronomy ,Astronomy and Astrophysics ,Planetary system ,Astrophysics - Astrophysics of Galaxies ,Exoplanet ,Habitability of orange dwarf systems ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,Radial velocity ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,[SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Circumstellar habitable zone ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Exoplanets of a few Earth masses can be now detected around nearby low-mass stars using Doppler spectroscopy. In this paper, we investigate the radial velocity variations of Kapteyn's star, which is both a sub-dwarf M-star and the nearest halo object to the Sun. The observations comprise archival and new HARPS, HIRES and PFS Doppler measurements. Two Doppler signals are detected at periods of 48 and 120 days using likelihood periodograms and a Bayesian analysis of the data. Using the same techniques, the activity indicies and archival ASAS-3 photometry show evidence for low-level activity periodicities of the order of several hundred days. However, there are no significant correlations with the radial velocity variations on the same time-scales. The inclusion of planetary Keplerian signals in the model results in levels of correlated and excess white noise that are remarkably low compared to younger G, K and M dwarfs. We conclude that Kapteyn's star is most probably orbited by two super-Earth mass planets, one of which is orbiting in its circumstellar habitable zone, becoming the oldest potentially habitable planet known to date. The presence and long-term survival of a planetary system seems a remarkable feat given the peculiar origin and kinematic history of Kapteyn's star. The detection of super-Earth mass planets around halo stars provides important insights into planet-formation processes in the early days of the Milky Way., Comment: MNRAS:Letters, submitted April 14, Accepted May 27, 2014. Consists of 6 pages, 2 figures and 2 tables
- Published
- 2014
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25. A Detailed Analysis of the HD 73526 2:1 Resonant Planetary System
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Xianyu Tan, Simon J. O'Toole, Pamela Arriagada, Duncan J. Wright, Dante Minniti, Jeremy Bailey, Brad D. Carter, Jeffrey D. Crane, Robert A. Wittenmyer, Marco Aurelio Diaz, Ian B. Thompson, Hugh R. A. Jones, R. P. Butler, Jonathan Horner, S. A. Schectman, Man Hoi Lee, C. G. Tinney, and Graeme Salter
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Amplitude ,Space and Planetary Science ,Planet ,Resonance ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Planetary system ,Stability (probability) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present six years of new radial-velocity data from the Anglo-Australian and Magellan Telescopes on the HD 73526 2:1 resonant planetary system. We investigate both Keplerian and dynamical (interacting) fits to these data, yielding four possible configurations for the system. The new data now show that both resonance angles are librating, with amplitudes of 40 degrees and 60 degrees, respectively. We then perform long-term dynamical stability tests to differentiate these solutions, which only differ significantly in the masses of the planets. We show that while there is no clearly preferred system inclination, the dynamical fit with i=90 degrees provides the best combination of goodness-of-fit and long-term dynamical stability., Accepted for publication in ApJ
- Published
- 2013
26. Two planetary companions around the K7 dwarf GJ 221 : a hot super-Earth and a candidate in the sub-Saturn desert range
- Author
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Dante Minniti, Pamela Arriagada, Stephen A. Shectman, Ian B. Thompson, Jeffrey D. Crane, R. Paul Butler, Guillem Anglada-Escudé, and S. Wende
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Super-Earth ,010504 meteorology & atmospheric sciences ,Metallicity ,Astronomy ,Minimum mass ,FOS: Physical sciences ,Astronomy and Astrophysics ,01 natural sciences ,Spectral line ,Orbit ,13. Climate action ,Space and Planetary Science ,Planet ,Saturn ,0103 physical sciences ,Low Mass ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report two low mass companions orbiting the nearby K7 dwarf GJ 221 that have emerged from re-analyzing 4.4 years of publicly available HARPS spectra complemented with 2 years of high precision Doppler measurements with Magellan/PFS. The HARPS measurements alone contain the clear signal of a low mass companion with a period of 125 days and a minimum mass of 53.2 \mearth (GJ 221b), falling in a mass range where very few planet candidates have been found (sub-Saturn desert). The addition of 17 PFS observations allow the confident detection of a second low mass companion (6.5 \mearth) in a hot orbit (3.87 days period, GJ 221c). Spectrocopic and photometric calibrations suggest that GJ 221 is slightly depleted ([Fe/H]$\sim$ -0.1) compared to the Sun so the presence of two low mass companions in the system confirms the trend that slightly reduced stellar metallicity does not prevent the formation of planets in the super-Earth to sub-Saturn mass regime., 29 pages, 12 figures, Accepted for publication on ApJ
- Published
- 2013
27. Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
- Author
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Joel D. Hartman, Pamela Arriagada, R. Paul Butler, Gáspár Á. Bakos, Stephen A. Shectman, Geoffrey W. Marcy, Ian B. Thompson, Jeffrey D. Crane, John Asher Johnson, Joshua N. Winn, Teruyuki Hirano, Andrew W. Howard, Simon Albrecht, Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Albrecht, Simon H., and Winn, Joshua Nathan
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Protoplanetary disk ,01 natural sciences ,Stars ,Tilt (optics) ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We provide evidence that the obliquities of stars with close-in giant planets were initially nearly random, and that the low obliquities that are often observed are a consequence of star-planet tidal interactions. The evidence is based on 14 new measurements of the Rossiter-McLaughlin effect (for the systems HAT-P-6, HAT-P-7, HAT-P-16, HAT-P-24, HAT-P-32, HAT-P-34, WASP-12, WASP-16, WASP-18, WASP-19, WASP-26, WASP-31, Gl 436, and Kepler-8), as well as a critical review of previous observations. The low-obliquity (well-aligned) systems are those for which the expected tidal timescale is short, and likewise the high-obliquity (misaligned and retrograde) systems are those for which the expected timescale is long. At face value, this finding indicates that the origin of hot Jupiters involves dynamical interactions like planet-planet interactions or the Kozai effect that tilt their orbits rather than inspiraling due to interaction with a protoplanetary disk. We discuss the status of this hypothesis and the observations that are needed for a more definitive conclusion., United States. National Aeronautics and Space Administration (Award NNX09AB33G), National Science Foundation (U.S.) (Grant 1108595)
- Published
- 2012
28. Chromospheric activity of Southern Stars from the Magellan Planet Search Program
- Author
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Pamela Arriagada
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Planetary habitability ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,K-line ,Spectral line ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Observatory ,Planet ,Southern Hemisphere ,Main sequence ,Geology ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
I present chromospheric activity measurements of ~ 670 F, G, K and M main sequence stars in the Southern Hemisphere, from ~8000 archival high-resolution echelle spectra taken at Las Campanas Observatory since 2004. These stars were targets from the Old Magellan Planet Search, and are now potential targets for the New Magellan Planet Search that will look for rocky and habitable planets. Activity indexes (S-values) are derived from Ca II H & K line cores and then converted to the Mt. Wilson system. From these measurements, chromospheric (logrhk) indexes are derived, which are then used as indicators of the level of radial-velocity jitter, age and rotation periods these stars present., 6 Figure. Accepted for publication on ApJ
- Published
- 2011
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29. HAT-P-27b: A Hot Jupiter Transiting a G Star on a 3 Day Orbit
- Author
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G. Perumpilly, Robert P. Stefanik, Istvan Papp, J. Lázár, John A. Johnson, Andrés Jordán, Gilbert A. Esquerdo, Pamela Arriagada, Geoffrey W. Marcy, B. Béky, Géza Kovács, Guillermo Torres, R. W. Noyes, Joel D. Hartman, Lars A. Buchhave, Daniel Bayliss, Andrew W. Howard, Debra A. Fischer, P. Sári, S. N. Quinn, David W. Latham, Dimitar Sasselov, László L. Kiss, and Gáspár Á. Bakos
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Dwarf star ,010308 nuclear & particles physics ,Metallicity ,FOS: Physical sciences ,Astronomy and Astrophysics ,Radius ,Astrophysics ,Effective temperature ,Orbital period ,01 natural sciences ,7. Clean energy ,Exoplanet ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,0103 physical sciences ,Hot Jupiter ,Transit (astronomy) ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V=12.214). The orbital period is 3.039586 +/- 0.000012 d, the reference epoch of transit is 2455186.01879 +/- 0.00054 (BJD), and the transit duration is 0.0705 +/- 0.0019 d. The host star with its effective temperature 5300 +/- 90 K is somewhat cooler than the Sun, and is more metal-rich with a metallicity of +0.29 +/- 0.10. Its mass is 0.94 +/- 0.04 Msun and radius is 0.90 +/- 0.04 Rsun. For the planetary companion we determine a mass of 0.660 +/- 0.033 MJ and radius of 1.038 +0.077 -0.058 RJ. For the 30 known transiting exoplanets between 0.3 MJ and 0.8 MJ, a negative correlation between host star metallicity and planetary radius, and an additional dependence of planetary radius on equilibrium temperature are confirmed at a high level of statistical significance., Submitted to ApJ on 2011-01-18. 12 pages, 7 figures, 7 tables
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- 2011
30. Five Long-period Extrasolar Planets in Eccentric orbits from the Magellan Planet Search Program
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Alan P. Boss, Pamela Arriagada, Stephen A. Shectman, Dante Minniti, John Chambers, Fred C. Adams, R. Paul Butler, and Mercedes Lopez-Morales
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Metallicity ,media_common.quotation_subject ,Astronomy ,Minimum mass ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Exoplanet ,Space and Planetary Science ,Planet ,Long period ,Astrophysics::Solar and Stellar Astrophysics ,High Energy Physics::Experiment ,Astrophysics::Earth and Planetary Astrophysics ,Eccentricity (behavior) ,Astrophysics::Galaxy Astrophysics ,media_common ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Five new planets orbiting G and K dwarfs have emerged from the Magellan velocity survey. These companions are jovian-mass planets in eccentric (e \geq 0.24) intermediate and long-period orbits. HD 86226b orbits a solar metallicity G2 dwarf. The MP sin i mass of the planet is 1.5 MJUP, the semi-major axis is 2.6 AU, and the eccentricity 0.73. HD 129445b orbits a metal rich G6 dwarf. The minimum mass of the planet is MP sin i =1.6 MJUP, the semi-major axis is 2.9 AU, and the eccentricity 0.70. HD 164604b orbits a K2 dwarf. The MP sin i mass is 2.7 MJUP, semi-major axis is 1.3 AU, and the eccentricity is 0.24. HD 175167b orbits a metal rich G5 star. The MP sin i mass is 7.8 MJUP, the semi-major axis is 2.4 AU, and the eccentricity 0.54. HD 152079b orbits a G6 dwarf. The MP sin i mass of the planet is 3 MJUP, the semi-major axis is 3.2 AU, and the eccentricity is 0.60., Accepted for publication on ApJ, 27 pages, 9 figures
- Published
- 2010
31. Low Mass Companions for Five Solar-Type Stars from the Magellan Planet Search Program
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Pamela Arriagada, Mercedes Lopez-Morales, Alan P. Boss, Stephen A. Shectman, Dante Minniti, Fred C. Adams, R. Paul Butler, and John Chambers
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Physics ,Astrophysics (astro-ph) ,Brown dwarf ,FOS: Physical sciences ,Astronomy and Astrophysics ,Orbital eccentricity ,Doppler velocity ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Stars ,Space and Planetary Science ,Planet ,Long period ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Low Mass ,Astrophysics::Galaxy Astrophysics - Abstract
We report low mass companions orbiting five Solar-type stars that have emerged from the Magellan precision Doppler velocity survey, with minimum (Msini) masses ranging from 1.2 to 25 Mjup. These nearby target stars range from mildly metal-poor to metal-rich, and appear to have low chromospheric activity. The companions to the brightest two of these stars have previously been reported from the CORALIE survey. Four of these companions (HD 48265-b, HD 143361-b, HD 28185-b, HD 111232-b) are low-mass Jupiter-like planets in eccentric intermediate and long-period orbits. On the other hand, the companion to HD 43848 appears to be a long period brown dwarf in a very eccentric orbit., Accepted for publication on ApJ, 26 pages, 10 figures, 7 tables
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- 2008
32. Two Jupiter-Mass Planets Orbiting HD 154672 and HD 205739
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Fred C. Adams, Debra A. Fischer, Dante Minniti, Stephen A. Shectman, Mercedes Lopez-Morales, R. Paul Butler, Genya Takeda, Pamela Arriagada, and Jason T. Wright
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Physics ,010308 nuclear & particles physics ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Star (graph theory) ,Orbital period ,01 natural sciences ,Stars ,symbols.namesake ,Space and Planetary Science ,Planet ,0103 physical sciences ,symbols ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Doppler effect ,Jupiter mass ,Astrophysics::Galaxy Astrophysics - Abstract
We report the detection of the first two planets from the N2K Doppler planet search program at the Magellan telescopes. The first planet has a mass of M sin i = 4.96 M_Jup and is orbiting the G3 IV star HD154672 with an orbital period of 163.9 days. The second planet is orbiting the F7 V star HD205739 with an orbital period of 279.8 days and has a mass of M sin i = 1.37 M_Jup. Both planets are in eccentric orbits, with eccentricities e = 0.61 and e = 0.27, respectively. Both stars are metal rich and appear to be chromospherically inactive, based on inspection of their Ca II H and K lines. Finally, the best Keplerian model fit to HD205739b shows a trend of 0.0649 m/s/day, suggesting the presence of an additional outer body in that system., 16 pages, 5 figures, accepted for publication on AJ
- Published
- 2008
33. Red Optical Planet Survey: A radial velocity search for low mass M dwarf planets
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Dante Minniti, John R. Barnes, P. Rojo, D. J. Pinfield, Andrés Jordán, Hugh R. A. Jones, Mikko Tuomi, Pamela Arriagada, James S. Jenkins, and Sandra V. Jeffers
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Physics ,Photon ,010308 nuclear & particles physics ,QC1-999 ,Dwarf planet ,Astronomy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Radial velocity ,13. Climate action ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Low Mass ,010303 astronomy & astrophysics ,Spectrograph ,Astrophysics::Galaxy Astrophysics - Abstract
We present radial velocity results from our Red Optical Planet Survey (ROPS), aimed at detecting low-mass planets orbiting mid-late M dwarfs. The ∼10 ms−1 precision achieved over 2 consecutive nights with the MIKE spectrograph at Magellan Clay is also found on week long timescales with UVES at VLT. Since we find that UVES is expected to attain photon limited precision of order 2 ms−1 using our novel deconvolution technique, we are limited only by the (≤10 ms−1) stability of atmospheric lines. Rocky planet frequencies of η⊕ = 0.3−0.7 lead us to expect high planet yields, enabling determination of η⊕ for the uncharted mid-late M dwarfs with modest surveys.
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- 2013
34. MagAO Imaging of Long-period Objects (MILO). I. A Benchmark M Dwarf Companion Exciting a Massive Planet around the Sun-like Star HD 7449
- Author
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Jeffrey D. Crane, Timothy J. Rodigas, Alycia J. Weinberger, Mercedes Lopez-Morales, Matías R. Díaz, Ian B. Thompson, Jackie Faherty, Dante Minniti, Stephen A. Shectman, Alan P. Boss, Katie M. Morzinski, Pamela Arriagada, Johanna Teske, Nathan A. Kaib, Jared R. Males, Guillem Anglada-Escudé, Philip M. Hinz, Laird M. Close, Fred C. Adams, and R. Paul Butler
- Subjects
radial velocities [Ttechniques] ,Star (game theory) ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,010309 optics ,Primary (astronomy) ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,individual (HD 7449) [Stars] ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,general [Binaries] ,Astronomy and Astrophysics ,Planetary system ,adaptive optics [Instrumentation] ,Radial velocity ,Orbit ,Planetary systems ,high angular resolution [Techniques] ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Spectral energy distribution ,Astrophysics::Earth and Planetary Astrophysics ,Eccentricity (mathematics) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present high-contrast Magellan adaptive optics (MagAO) images of HD 7449, a Sun-like star with one planet and a long-term radial velocity (RV) trend. We unambiguously detect the source of the long-term trend from 0.6-2.15 \microns ~at a separation of \about 0\fasec 54. We use the object's colors and spectral energy distribution to show that it is most likely an M4-M5 dwarf (mass \about 0.1-0.2 \msun) at the same distance as the primary and is therefore likely bound. We also present new RVs measured with the Magellan/MIKE and PFS spectrometers and compile these with archival data from CORALIE and HARPS. We use a new Markov chain Monte Carlo procedure to constrain both the mass ($> 0.17$ \msun ~at 99$\%$ confidence) and semimajor axis (\about 18 AU) of the M dwarf companion (HD 7449B). We also refine the parameters of the known massive planet (HD 7449Ab), finding that its minimum mass is $1.09^{+0.52}_{-0.19}$ \mj, its semimajor axis is $2.33^{+0.01}_{-0.02}$ AU, and its eccentricity is $0.8^{+0.08}_{-0.06}$. We use N-body simulations to constrain the eccentricity of HD 7449B to $\lesssim$ 0.5. The M dwarf may be inducing Kozai oscillations on the planet, explaining its high eccentricity. If this is the case and its orbit was initially circular, the mass of the planet would need to be $\lesssim$ 1.5 \mj. This demonstrates that strong constraints on known planets can be made using direct observations of otherwise undetectable long-period companions., Corrected planet mass error (7.8 Mj --> 1.09 Mj, in agreement with previous studies)
35. A planetary system around the nearby M dwarf GJ 667C with at least one super-Earth in its habitable zone
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Hugh R. A. Jones, Dante Minniti, Nader Haghighipour, Steven S. Vogt, Stephen A. Shectman, Jeremy Bailey, Eugenio J. Rivera, Brad D. Carter, Guillem Anglada-Escudé, R. Paul Butler, Simon J. O'Toole, C. G. Tinney, Robert A. Wittenmyer, Ian B. Thompson, Jeffrey D. Crane, Pamela Arriagada, and James S. Jenkins
- Subjects
Physics ,Rotation period ,Earth and Planetary Astrophysics (astro-ph.EP) ,Proper motion ,Super-Earth ,010504 meteorology & atmospheric sciences ,Gas giant ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Planetary system ,01 natural sciences ,Radial velocity ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,10. No inequality ,010303 astronomy & astrophysics ,Circumstellar habitable zone ,Astrophysics - Earth and Planetary Astrophysics ,0105 earth and related environmental sciences - Abstract
We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the ESO public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/PFS and Keck/HIRES spectrometers, reveals 3 additional signals beyond the previously reported 7.2-day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (Period sim 10 years). The 28-day signal implies a planet candidate with a minimum mass of 4.5 Mearth orbiting well within the canonical definition of the star's liquid water habitable zone, this is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition and interior dynamics. The 75-day signal is less certain, being significantly affected by aliasing interactions among a potential 91-day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal poor compared to the Sun. The presence of a super-Earth in the habitable zone of a metal poor M dwarf in a triple star system, supports the evidence that such worlds should be ubiquitous in the Galaxy., Comment: Accepted in ApJ Letters, 16 pages, 3 figures and 1 table
36. The Test Case of HD 26965: Difficulties Disentangling Weak Doppler Signals from Stellar Activity.
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Matías R. Díaz, James S. Jenkins, Mikko Tuomi, R. Paul Butler, Maritza G. Soto, Johanna K. Teske, Fabo Feng, Stephen A. Shectman, Pamela Arriagada, Jeffrey D. Crane, Ian B. Thompson, and Steven S. Vogt
- Published
- 2018
- Full Text
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37. A Six-planet System around the Star HD 34445.
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Steven S. Vogt, R. Paul Butler, Jennifer Burt, Mikko Tuomi, Gregory Laughlin, Brad Holden, Johanna K. Teske, Stephen A. Shectman, Jeffrey D. Crane, Matías Díaz, Ian B. Thompson, Pamela Arriagada, and Sandy Keiser
- Published
- 2017
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38. The LCES HIRES/Keck Precision Radial Velocity Exoplanet Survey.
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R. Paul Butler, Steven S. Vogt, Gregory Laughlin, Jennifer A. Burt, Eugenio J. Rivera, Mikko Tuomi, Johanna Teske, Pamela Arriagada, Matias Diaz, Brad Holden, and Sandy Keiser
- Published
- 2017
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39. MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). II. A PUZZLING WHITE DWARF AROUND THE SUN-LIKE STAR HD 11112.
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Timothy J. Rodigas, P. Bergeron, Amélie Simon, Pamela Arriagada, Jacqueline K. Faherty, Guillem Anglada-Escudé, Eric E. Mamajek, Alycia Weinberger, R. Paul Butler, Jared R. Males, Katie Morzinski, Laird M. Close, Philip M. Hinz, Jeremy Bailey, Brad Carter, James S. Jenkins, Hugh Jones, Simon O’Toole, C. G. Tinney, and Rob Wittenmyer
- Subjects
RADIAL velocity of stars ,ADAPTIVE optics ,MARKOV processes ,MONTE Carlo method ,WAVELENGTHS - Abstract
HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2.″2 (100 au) at multiple wavelengths spanning 0.6–4 μm and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9–1.1 M
⊙ , which corresponds to very high eccentricity, near edge-on orbits from a Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is >2σ, which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years. [ABSTRACT FROM AUTHOR]- Published
- 2016
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40. THE K2-ESPRINT PROJECT. V. A SHORT-PERIOD GIANT PLANET ORBITING A SUBGIANT STAR.
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Vincent Van Eylen, Simon Albrecht, Davide Gandolfi, Fei Dai, Joshua N. Winn, Teriyuki Hirano, Norio Narita, Hans Bruntt, Jorge Prieto-Arranz, Víctor J. S. Béjar, Grzegorz Nowak, Mikkel N. Lund, Enric Palle, Ignasi Ribas, Roberto Sanchis-Ojeda, Liang Yu, Pamela Arriagada, R. Paul Butler, Jeffrey D. Crane, and Rasmus Handberg
- Published
- 2016
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41. DOPPLER MONITORING OF FIVE K2 TRANSITING PLANETARY SYSTEMS.
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Fei Dai, Joshua N. Winn, Simon Albrecht, Pamela Arriagada, Allyson Bieryla, R. Paul Butler, Jeffrey D. Crane, Teriyaki Hirano, John Asher Johnson, Amanda Kiilerich, David W. Latham, Norio Narita, Grzegorz Nowak, Enric Palle, Ignasi Ribas, Leslie A. Rogers, Roberto Sanchis-Ojeda, Stephen A. Shectman, Johanna K. Teske, and Ian B. Thompson
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PLANETARY systems ,ROTATIONAL motion ,RESONANT states ,FORCED vibration (Mechanics) ,KINEMATICS - Abstract
In an effort to measure the masses of planets discovered by the NASA K2 mission, we have conducted precise Doppler observations of five stars with transiting planets. We present the results of a joint analysis of these new data and previously published Doppler data. The first star, an M dwarf known as K2-3 or EPIC 201367065, has three transiting planets (“b,” with radius “c,” and “d,” ). Our analysis leads to the mass constraints: and M
c < 4.2 M⊕ (95% confidence). The mass of planet d is poorly constrained because its orbital period is close to the stellar rotation period, making it difficult to disentangle the planetary signal from spurious Doppler shifts due to stellar activity. The second star, a G dwarf known as K2-19 or EPIC 201505350, has two planets (“b,” 7.7 R⊕ ; and “c,” 4.9 R⊕ ) in a 3:2 mean-motion resonance, as well as a shorter-period planet (“d,” 1.1 R⊕ ). We find Mb = , Mc = and Md < 14.0 M⊕ (95% conf.). The third star, a G dwarf known as K2-24 or EPIC 203771098, hosts two transiting planets (“b,” 5.7 R⊕ ; and “c,” 7.8 R⊕ ) with orbital periods in a nearly 2:1 ratio. We find Mb = and Mc = . The fourth star, a G dwarf known as EPIC 204129699, hosts a hot Jupiter for which we measured the mass to be . The fifth star, a G dwarf known as EPIC 205071984, contains three transiting planets (“b,” 5.4 R⊕ ; “c,” 3.5 R⊕ ; and “d,” 3.8 R⊕ ), the outer two of which have a nearly 2:1 period ratio. We find Mb = , Mc < (95% conf.) and Md < 35 M⊕ (95% conf.). [ABSTRACT FROM AUTHOR]- Published
- 2016
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42. MagAO IMAGING OF LONG-PERIOD OBJECTS (MILO). I. A BENCHMARK M DWARF COMPANION EXCITING A MASSIVE PLANET AROUND THE SUN-LIKE STAR HD 7449.
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Timothy J. Rodigas, Pamela Arriagada, Jackie Faherty, Guillem Anglada-Escudé, Nathan Kaib, R. Paul Butler, Stephen Shectman, Alycia Weinberger, Jared R. Males, Katie M. Morzinski, Laird M. Close, Philip M. Hinz, Jeffrey D. Crane, Ian Thompson, Johanna Teske, Matías Díaz, Dante Minniti, Mercedes Lopez-Morales, Fred C. Adams, and Alan P. Boss
- Subjects
- *
LIGHT sources , *MARKOV processes , *ADAPTIVE optics , *CELESTIAL mechanics , *OSCILLATIONS - Abstract
We present high-contrast Magellan adaptive optics images of HD 7449, a Sun-like star with one planet and a long-term radial velocity (RV) trend. We unambiguously detect the source of the long-term trend from 0.6–2.15 μm at a separation of ∼0.″54. We use the object’s colors and spectral energy distribution to show that it is most likely an M4–M5 dwarf (mass ∼0.1–0.2 ) at the same distance as the primary and is therefore likely bound. We also present new RVs measured with the Magellan/MIKE and Planet Finder Spectrograph spectrometers and compile these with archival data from CORALIE and HARPS. We use a new Markov chain Monte Carlo procedure to constrain both the mass ( at 99% confidence) and semimajor axis (∼18 AU) of the M dwarf companion (HD 7449B). We also refine the parameters of the known massive planet (HD 7449Ab), finding that its minimum mass is MJ, its semimajor axis is AU, and its eccentricity is . We use N-body simulations to constrain the eccentricity of HD 7449B to ≲0.5. The M dwarf may be inducing Kozai oscillations on the planet, explaining its high eccentricity. If this is the case and its orbit was initially circular, the mass of the planet would need to be ≲1.5 MJ. This demonstrates that strong constraints on known planets can be made using direct observations of otherwise undetectable long-period companions. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
43. THE LICK-CARNEGIE EXOPLANET SURVEY: HD 32963—A NEW JUPITER ANALOG ORBITING A SUN-LIKE STAR.
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Dominick Rowan, Stefano Meschiari, Gregory Laughlin, Steven S. Vogt, R. Paul Butler, Jennifer Burt, Songhu Wang, Brad Holden, Russell Hanson, Pamela Arriagada, Sandy Keiser, Johanna Teske, and Matias Diaz
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STARS ,JUPITER (Planet) ,PLANETARY systems ,PLANETS ,RADIAL velocity of galaxies - Abstract
We present a set of 109 new, high-precision Keck/HIRES radial velocity (RV) observations for the solar-type star HD 32963. Our data set reveals a candidate planetary signal with a period of 6.49 ± 0.07 years and a corresponding minimum mass of 0.7 ± 0.03 Jupiter masses. Given Jupiter's crucial role in shaping the evolution of the early Solar System, we emphasize the importance of long-term RV surveys. Finally, using our complete set of Keck radial velocities and correcting for the relative detectability of synthetic planetary candidates orbiting each of the 1122 stars in our sample, we estimate the frequency of Jupiter analogs across our survey at approximately 3%. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
44. SIX PLANETS ORBITING HD 219134.
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Steven S. Vogt, Jennifer Burt, Stefano Meschiari, R. Paul Butler, Gregory W. Henry, Songhu Wang, Brad Holden, Cyril Gapp, Russell Hanson, Pamela Arriagada, Sandy Keiser, Johanna Teske, and Gregory Laughlin
- Subjects
ORBITS (Astronomy) ,PLANETARY orbits ,CELESTIAL mechanics ,SOLAR system ,DOPPLER effect - Abstract
We present new, high-precision Doppler radial velocity (RV) data sets for the nearby K3V star HD 219134. The data include 175 velocities obtained with the HIRES Spectrograph at the Keck I Telescope and 101 velocities obtained with the Levy Spectrograph at the Automated Planet Finder Telescope at Lick Observatory. Our observations reveal six new planetary candidates, with orbital periods of P = 3.1, 6.8, 22.8, 46.7, 94.2, and 2247 days, spanning masses of 3.5, 8.9, 21.3, 10.8, and , respectively. Our analysis indicates that the outermost signal is unlikely to be an artifact induced by stellar activity. In addition, several years of precision photometry with the T10 0.8 m automatic photometric telescope at Fairborn Observatory demonstrated a lack of brightness variability to a limit of ∼0.0002 mag, providing strong support for planetary-reflex motion as the source of the RV variations. The HD 219134 system with its bright (V = 5.6) primary provides an excellent opportunity to obtain detailed orbital characterization (and potentially follow-up observations) of a planetary system that resembles many of the multiple-planet systems detected by Kepler, which are expected to be detected by NASA’s forthcoming TESS Mission and by ESA’s forthcoming PLATO Mission. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
45. DOPPLER MONITORING OF THE WASP-47 MULTIPLANET SYSTEM.
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Fei Dai, Joshua N. Winn, Pamela Arriagada, R. Paul Butler, Jeffrey D. Crane, John Asher Johnson, Stephen A. Shectman, Johanna K. Teske, Ian B. Thompson, Andrew Vanderburg, and Robert A. Wittenmyer
- Published
- 2015
- Full Text
- View/download PDF
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