61 results on '"Benjamin M. Tofflemire"'
Search Results
2. TESS Hunt for Young and Maturing Exoplanets (THYME). X. A Two-planet System in the 210 Myr MELANGE-5 Association
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Pa Chia Thao, Andrew W. Mann, Madyson G. Barber, Adam L. Kraus, Benjamin M. Tofflemire, Jonathan L. Bush, Mackenna L. Wood, Karen A. Collins, Andrew Vanderburg, Samuel N. Quinn, George Zhou, Elisabeth R. Newton, Carl Ziegler, Nicholas Law, Khalid Barkaoui, Francisco J. Pozuelos, Mathilde Timmermans, Michaël Gillon, Emmanuël Jehin, Richard P. Schwarz, Tianjun Gan, Avi Shporer, Keith Horne, Ramotholo Sefako, Olga Suarez, Djamel Mekarnia, Tristan Guillot, Lyu Abe, Amaury H. M. J. Triaud, Don J. Radford, Ana Isabel Lopez Murillo, George R. Ricker, Joshua N. Winn, Jon M. Jenkins, Luke G. Bouma, Michael Fausnaugh, Natalia M. Guerrero, and Michelle Kunimoto
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Exoplanet astronomy ,Transit photometry ,Stellar ages ,Young star clusters ,Stellar activity ,Transit timing variation method ,Astronomy ,QB1-991 - Abstract
Young (
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- 2024
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3. Sites of Planet Formation in Binary Systems. I. Evidence for Disk−Orbit Alignment in the Close Binary FO Tau
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Benjamin M. Tofflemire, Lisa Prato, Adam L. Kraus, Dominique Segura-Cox, G. H. Schaefer, Rachel Akeson, Sean Andrews, Eric L. N. Jensen, Christopher M. Johns-Krull, J. J. Zanazzi, and M. Simon
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Young stellar objects ,Protoplanetary disks ,Binary stars ,Close binary stars ,Astronomy ,QB1-991 - Abstract
Close binary systems present challenges to planet formation. As binary separations decrease, so do the occurrence rates of protoplanetary disks in young systems and planets in mature systems. For systems that do retain disks, their disk masses and sizes are altered by the presence of the binary companion. Through the study of protoplanetary disks in binary systems with known orbital parameters, we seek to determine the properties that promote disk retention and therefore planet formation. In this work, we characterize the young binary−disk system FO Tau. We determine the first full orbital solution for the system, finding masses of ${0.35}_{-0.05}^{+0.06}\ {M}_{\odot }$ and 0.34 ± 0.05 M _⊙ for the stellar components, a semimajor axis of $22{\,(}_{-1}^{+2})$ au, and an eccentricity of $0.21{\,(}_{-0.03}^{+0.04})$ . With long-baseline Atacama Large Millimeter/submillimeter Array interferometry, we detect 1.3 mm continuum and ^12 CO ( J = 2–1) line emission toward each of the binary components; no circumbinary emission is detected. The protoplanetary disks are compact, consistent with being truncated by the binary orbit. The dust disks are unresolved in the image plane, and the more extended gas disks are only marginally resolved. Fitting the continuum and CO visibilities, we determine the inclination of each disk, finding evidence for alignment of the disk and binary orbital planes. This study is the first of its kind linking the properties of circumstellar protoplanetary disks to a precisely known binary orbit. In the case of FO Tau, we find a dynamically placid environment (coplanar, low eccentricity), which may foster its potential for planet formation.
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- 2024
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4. TESS Hunt for Young and Maturing Exoplanets (THYME). XI. An Earth-sized Planet Orbiting a Nearby, Solar-like Host in the 400 Myr Ursa Major Moving Group
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Benjamin K. Capistrant, Melinda Soares-Furtado, Andrew Vanderburg, Alyssa Jankowski, Andrew W. Mann, Gabrielle Ross, Gregor Srdoc, Natalie R. Hinkel, Juliette Becker, Christian Magliano, Mary Anne Limbach, Alexander P. Stephan, Andrew C. Nine, Benjamin M. Tofflemire, Adam L. Kraus, Steven Giacalone, Joshua N. Winn, Allyson Bieryla, Luke G. Bouma, David R. Ciardi, Karen A. Collins, Giovanni Covone, Zoë L. de Beurs, Chelsea X. Huang, Jon M. Jenkins, Laura Kreidberg, David W. Latham, Samuel N. Quinn, Sara Seager, Avi Shporer, Joseph D. Twicken, Bill Wohler, Roland K. Vanderspek, Ricardo Yarza, and Carl Ziegler
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Exoplanet systems ,Astronomy ,QB1-991 - Abstract
Young terrestrial worlds are critical test beds to constrain prevailing theories of planetary formation and evolution. We present the discovery of HD 63433 d—a nearby (22 pc), Earth-sized planet transiting a young Sun-like star (TOI-1726, HD 63433). HD 63433 d is the third planet detected in this multiplanet system. The kinematic, rotational, and abundance properties of the host star indicate that it belongs to the young (414 ± 23 Myr) Ursa Major moving group, whose membership we update using new data from the third data release of the Gaia mission and TESS. Our transit analysis of the TESS light curves indicates that HD 63433 d has a radius of 1.1 R _⊕ and closely orbits its host star with a period of 4.2 days. To date, HD 63433 d is the smallest confirmed exoplanet with an age less than 500 Myr, and the nearest young Earth-sized planet. Furthermore, the apparent brightness of the stellar host ( V ≃ 6.9 mag) makes this transiting multiplanet system favorable to further investigations, including spectroscopic follow-up to probe the atmospheric loss in a young Earth-sized world.
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- 2024
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5. The Strength and Variability of the Helium 10830 Å Triplet in Young Stars, with Implications for Exosphere Detection
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Daniel M. Krolikowski, Adam L. Kraus, Benjamin M. Tofflemire, Caroline V. Morley, Andrew W. Mann, and Andrew Vanderburg
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Stellar activity ,Atomic spectroscopy ,Exoplanet atmospheres ,Stellar chromospheres ,Astronomy ,QB1-991 - Abstract
Young exoplanets trace planetary evolution, in particular the atmospheric mass loss that is most dynamic in youth. However, the high activity level of young stars can mask or mimic the spectroscopic signals of atmospheric mass loss. This includes the activity-sensitive He 10830 Å triplet, which is an increasingly important exospheric probe. To characterize the He-10830 triplet at young ages, we present time-series NIR spectra for young transiting planet hosts taken with the Habitable-zone Planet Finder. The He-10830 absorption strength is similar across our sample, except at the fastest and slowest rotations, indicating that young chromospheres are dense and populate metastable helium via collisions. Photoionization and recombination by coronal radiation only dominates metastable helium population at the active and inactive extremes. Volatile stellar activity, such as flares and changing surface features, drives variability in the He-10830 triplet. Variability is largest at the youngest ages before decreasing to ≲5–10 mÅ (or 3%) at ages above 300 Myr, with six of eight stars in this age range agreeing with there being no intrinsic variability. He-10830 triplet variability is smallest and age-independent at the shortest timescales. Intrinsic stellar variability should not preclude detection of young exospheres, except at the youngest ages. We recommend out-of-transit comparison observations taken directly surrounding transit and observation of multiple transits to minimize activity’s effect. Regardless, caution is necessary when interpreting transit observations in the context of stellar activity, as many scenarios can lead to enhanced stellar variability even on timescales of an hour.
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- 2024
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6. A Search for Stellar Siblings of the ∼200 Myr TOI-251 b Planetary System
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Qinghui Sun, Sharon Xuesong Wang, Andrew W. Mann, Benjamin M. Tofflemire, Adam L. Kraus, Tianjun Gan, and Madyson G. Barber
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Stellar associations ,Exoplanet evolution ,Early stellar evolution ,Stellar dynamics ,Stellar ages ,Stellar rotation ,Astrophysics ,QB460-466 - Abstract
Young planets (
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- 2023
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7. An Eclipsing Binary Comprising Two Active Red Stragglers of Identical Mass and Synchronized Rotation: A Post-mass-transfer System or Just Born That Way?
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Keivan G. Stassun, Guillermo Torres, Marina Kounkel, Benjamin M. Tofflemire, Emily Leiner, Dax L. Feliz, Don M. Dixon, Robert D. Mathieu, Natalie Gosnell, and Michael Gully-Santiago
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Fundamental parameters of stars ,Stellar evolution ,Stellar activity ,Eclipsing binary stars ,Red straggler stars ,Astrophysics ,QB460-466 - Abstract
We report the discovery of 2M0056–08 as an equal-mass eclipsing binary (EB), comprising two red straggler stars (RSSs) with an orbital period of 33.9 days. Both stars have masses of ≈1.419 M _⊙ , identical to within 0.2%. Both stars appear to be in the early red-giant phase of evolution; however, they are far displaced to cooler temperatures and lower luminosities compared to standard stellar models. The broadband spectral energy distribution shows NUV excess and X-ray emission, which is consistent with chromospheric and coronal emission from magnetically active stars. Indeed, the stars rotate more rapidly than typical red giants and they evince light-curve modulations due to spots. These modulations also reveal the stars to be rotating synchronously with one another. There is evidence for excess FUV emission and long-term modulations in radial velocities, although it is not clear if they are also attributable to magnetic activity or if they reveal a tertiary companion. Stellar evolution models that are modified to account for the effects of spots can reproduce the observed radii and temperatures of the RSSs. If the system possesses a white dwarf tertiary, then mass-transfer scenarios could explain the manner by which the stars came to possess such remarkably identical masses and by which they came to be synchronized. However, if the stars are presumed to have been formed as identical twins and they then managed to become tidally synchronized as they evolved toward the red-giant branch, then all of the features of the system can be explained via activity effects without requiring a complex dynamical history.
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- 2023
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8. A Low-mass, Pre-main-sequence Eclipsing Binary in the 40 Myr Columba Association—Fundamental Stellar Parameters and Modeling the Effect of Star Spots
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Benjamin M. Tofflemire, Adam L. Kraus, Andrew W. Mann, Elisabeth R. Newton, Michael A. Gully-Santiago, Andrew Vanderburg, William C. Waalkes, Zachory K. Berta-Thompson, Kevin I. Collins, Karen A. Collins, Louise D. Nielsen, François Bouchy, Carl Ziegler, César Briceño, and Nicholas M. Law
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M stars ,Eclipsing binary stars ,Starspots ,Pre-main sequence stars ,Astronomy ,QB1-991 - Abstract
Young eclipsing binaries (EBs) are powerful probes of early stellar evolution. Current models are unable to simultaneously reproduce the measured and derived properties that are accessible for EB systems (e.g., mass, radius, temperature, and luminosity). In this study we add a benchmark EB to the pre-main-sequence population with our characterization of TOI 450 (TIC 77951245). Using Gaia astrometry to identify its comoving, coeval companions, we confirm TOI 450 is a member of the ∼40 Myr Columba association. This eccentric ( e = 0.2969), equal-mass ( q = 1.000) system provides only one grazing eclipse. Despite this, our analysis achieves the precision of a double-eclipsing system by leveraging information in our high-resolution spectra to place priors on the surface-brightness and radius ratios. We also introduce a framework to include the effect of star spots on the observed eclipse depths. Multicolor eclipse light curves play a critical role in breaking degeneracies between the effects of star spots and limb-darkening. Including star spots reduces the derived radii by ∼2% from a unspotted model (>2 σ ) and inflates the formal uncertainty in accordance with our lack of knowledge regarding the starspot orientation. We derive masses of 0.1768( ± 0.0004) and 0.1767( ± 0.0003) M _⊙ , and radii of 0.345(±0.006) and 0.346(±0.006) R _⊙ for the primary and secondary, respectively. We compare these measurements to multiple stellar evolution isochones, finding good agreement with the association age. The MESA MIST and SPOTS ( f _s = 0.17) isochrones perform the best across our comparisons, but detailed agreement depends heavily on the quantities being compared.
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- 2023
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9. TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System
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Mackenna L. Wood, Andrew W. Mann, Madyson G. Barber, Jonathan L. Bush, Adam L. Kraus, Benjamin M. Tofflemire, Andrew Vanderburg, Elisabeth R. Newton, Gregory A. Feiden, George Zhou, Luke G. Bouma, Samuel N. Quinn, David J. Armstrong, Ares Osborn, Vardan Adibekyan, Elisa Delgado Mena, Sergio G. Sousa, Jonathan Gagné, Matthew J. Fields, Reilly P. Milburn, Pa Chia Thao, Stephen P. Schmidt, Crystal L. Gnilka, Steve B. Howell, Nicholas M. Law, Carl Ziegler, César Briceño, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Joshua E. Schlieder, Hugh P. Osborn, Joseph D. Twicken, David R. Ciardi, and Chelsea X. Huang
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Stellar ages ,Transit photometry ,Exoplanets ,Stellar associations ,Stellar kinematics ,Astronomy ,QB1-991 - Abstract
We report the discovery and characterization of a nearby (∼85 pc), older (27 ± 3 Myr), distributed stellar population near Lower Centaurus Crux (LCC), initially identified by searching for stars comoving with a candidate transiting planet from TESS (HD 109833; TOI 1097). We determine the association membership using Gaia kinematics, color–magnitude information, and rotation periods of candidate members. We measure its age using isochrones, gyrochronology, and Li depletion. While the association is near known populations of LCC, we find that it is older than any previously found LCC subgroup (10–16 Myr), and distinct in both position and velocity. In addition to the candidate planets around HD 109833, the association contains four directly imaged planetary-mass companions around three stars, YSES-1, YSES-2, and HD 95086, all of which were previously assigned membership in the younger LCC. Using the Notch pipeline, we identify a second candidate transiting planet around HD 109833. We use a suite of ground-based follow-up observations to validate the two transit signals as planetary in nature. HD 109833 b and c join the small but growing population of
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- 2023
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10. Erratum: 'TESS Hunt for Young and Maturing Exoplanets (THYME). VII. Membership, Rotation, and Lithium in the Young Cluster Group-X and a New Young Exoplanet' (2022, AJ, 164, 119)
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Elisabeth R. Newton, Rayna Rampalli, Adam L. Kraus, Andrew W. Mann, Jason L. Curtis, Andrew Vanderburg, Daniel M. Krolikowski, Daniel Huber, Grayson C. Petter, Allyson Bieryla, Benjamin M. Tofflemire, Pa Chia Thao, Mackenna L. Wood, Ronan Kerr, Boris S. Safanov, Ivan A. Strakhov, David R. Ciardi, Steven Giacalone, Courtney D. Dressing, Holden Gill, Arjun B. Savel, Karen A. Collins, Peyton Brown, Felipe Murgas, Keisuke Isogai, Norio Narita, Enric Palle, Samuel N. Quinn, Jason D. Eastman, Gábor Fűrész, Bernie Shiao, Tansu Daylan, Douglas A. Caldwell, George R. Ricker, Roland Vanderspek, Sara Seager, Joshua N. Winn, Jon M. Jenkins, and David W. Latham
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Astronomy ,QB1-991 - Published
- 2023
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11. Correlating Changes in Spot Filling Factors with Stellar Rotation: The Case of LkCa 4
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Facundo Pérez Paolino, Jeffrey S. Bary, Michael S. Petersen, Kimberly Ward-Duong, Benjamin M. Tofflemire, Katherine B. Follette, and Heidi Mach
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T Tauri stars ,Star formation ,Early stellar evolution ,Starspots ,Pre-main sequence stars ,Stellar evolutionary tracks ,Astrophysics ,QB460-466 - Abstract
We present a multi-epoch spectroscopic study of LkCa 4, a heavily spotted non-accreting T Tauri star. Using SpeX at NASA’s Infrared Telescope Facility (IRTF), 12 spectra were collected over five consecutive nights, spanning ≈1.5 stellar rotations. Using the IRTF SpeX Spectral Library, we constructed empirical composite models of spotted stars by combining a warmer (photosphere) standard star spectrum with a cooler (spot) standard weighted by the spot filling factor, f _spot . The best-fit models spanned two photospheric component temperatures, T _phot = 4100 K (K7V) and 4400 K (K5V), and one spot component temperature, T _spot = 3060 K (M5V) with an A _V of 0.3. We find values of f _spot to vary between 0.77 and 0.94 with an average uncertainty of ∼0.04. The variability of f _spot is periodic and correlates with its 3.374 day rotational period. Using a mean value for f ^mean _spot to represent the total spot coverage, we calculated spot corrected values for T _eff and L _⋆ . Placing these values alongside evolutionary models developed for heavily spotted young stars, we infer mass and age ranges of 0.45–0.6 M _⊙ and 0.50–1.25 Myr, respectively. These inferred values represent a twofold increase in the mass and a twofold decrease in the age as compared to standard evolutionary models. Such a result highlights the need for constraining the contributions of cool and warm regions of young stellar atmospheres when estimating T _eff and L _⋆ to infer masses and ages as well as the necessity for models to account for the effects of these regions on the early evolution of low-mass stars.
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- 2023
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12. TESS Hunt for Young and Maturing Exoplanets (THYME). VII. Membership, Rotation, and Lithium in the Young Cluster Group-X and a New Young Exoplanet
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Elisabeth R. Newton, Rayna Rampalli, Adam L. Kraus, Andrew W. Mann, Jason L. Curtis, Andrew Vanderburg, Daniel M. Krolikowski, Daniel Huber, Grayson C. Petter, Allyson Bieryla, Benjamin M. Tofflemire, Pa Chia Thao, Mackenna L. Wood, Ronan Kerr, Boris S. Safanov, Ivan A. Strakhov, David R. Ciardi, Steven Giacalone, Courtney D. Dressing, Holden Gill, Arjun B. Savel, Karen A. Collins, Peyton Brown, Felipe Murgas, Keisuke Isogai, Norio Narita, Enric Palle, Samuel N. Quinn, Jason D. Eastman, Gábor Fűrész, Bernie Shiao, Tansu Daylan, Douglas A. Caldwell, George R. Ricker, Roland Vanderspek, Sara Seager, Joshua N. Winn, Jon M. Jenkins, and David W. Latham
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Young star clusters ,Stellar rotation ,Exoplanets ,Astronomy ,QB1-991 - Abstract
The public, all-sky surveys Gaia and TESS provide the ability to identify new young associations and determine their ages. These associations enable study of planetary evolution by providing new opportunities to discover young exoplanets. A young association was recently identified by Tang et al. and Fürnkranz et al. using astrometry from Gaia (called “Group-X” by the former). In this work, we investigate the age and membership of this association, and we validate the exoplanet TOI 2048 b, which was identified to transit a young, late G dwarf in Group-X using photometry from TESS. We first identified new candidate members of Group-X using Gaia EDR3 data. To infer the age of the association, we measured rotation periods for candidate members using TESS data. The clear color–period sequence indicates that the association is the same age as the 300 ± 50 Myr old NGC 3532. We obtained optical spectra for candidate members that show lithium absorption consistent with this young age. Further, we serendipitously identify a new, small association nearby Group-X, which we call MELANGE-2. Lastly, we statistically validate TOI 2048 b, which is a 2.1 ± 0.2 R _⊕ radius planet on a 13.8-day orbit around its 300 Myr old host star.
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- 2022
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13. Transit Hunt for Young and Maturing Exoplanets (THYME). VIII. A Pleiades-age Association Harboring Two Transiting Planetary Systems from Kepler
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Madyson G. Barber, Andrew W. Mann, Jonathan L. Bush, Benjamin M. Tofflemire, Adam L. Kraus, Daniel M. Krolikowski, Andrew Vanderburg, Matthew J. Fields, Elisabeth R. Newton, Dylan A. Owens, and Pa Chia Thao
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- 2022
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14. TESS Hunt for Young and Maturing Exoplanets (THYME). V. A Sub-Neptune Transiting a Young Star in a Newly Discovered 250 Myr Association
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Benjamin M. Tofflemire, Aaron C. Rizzuto, Elisabeth R. Newton, Adam L. Kraus, Andrew W. Mann, Andrew Vanderburg, Tyler Nelson, Keith Hawkins, Mackenna L. Wood, George Zhou, Samuel N. Quinn, Steve B. Howell, Karen A. Collins, Richard P. Schwarz, Keivan G. Stassun, Luke G. Bouma, Zahra Essack, Hugh Osborn, Patricia T. Boyd, Gábor Fűrész, Ana Glidden, Joseph D. Twicken, Bill Wohler, Brian McLean, George R. Ricker, Roland Vanderspek, David W. Latham, S. Seager, Joshua N. Winn, and Jon M. Jenkins
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Astrophysics - Abstract
The detection and characterization of young planetary systems offer a direct path to study the processes that shape planet evolution. We report on the discovery of a sub-Neptune-sized planet orbiting the young star HD 110082 (TOI-1098). Transit events we initially detected during TESS Cycle 1 are validated with time-series photometry from Spitzer. High-contrast imaging and high-resolution, optical spectra are also obtained to characterize the stellar host and confirm the planetary nature of the transits. The host star is a late-F dwarf (M⁎ = 1.2Mꙩ) with a low-mass, M dwarf binary companion (M⁎ = 0.26Mꙩ) separated by nearly one arcminute (∼6200 au). Based on its rapid rotation and Lithium absorption, HD 110082 is young, but is not a member of any known group of young stars (despite proximity to the Octans association). To measure the age of the system, we search for coeval, phase-space neighbors and compile a sample of candidate siblings to compare with the empirical sequences of young clusters and to apply quantitative age-dating techniques. In doing so, we find that HD 110082 resides in a new young stellar association we designate MELANGE-1, with an age of 250(+50, -70) Myr. Jointly modeling the TESS and Spitzer light curves, we measure a planetary orbital period of 10.1827 days and radius of R(p) = 3.2 ± 0.1Rꚛ. HD 110082 b’s radius falls in the largest 12% of field-age systems with similar host-star mass and orbital period. This finding supports previous studies indicating that young planets have larger radii than their field-age counterparts.
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- 2021
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15. TESS Hunt for Young and Maturing Exoplanets (THYME). IV. Three Small Planets Orbiting a 120 Myr Old Star in the Pisces–Eridanus Stream*
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Elisabeth R. Newton, Andrew W. Mann, Adam L. Kraus, John H. Livingston, Andrew Vanderburg, Jason L. Curtis, Pa Chia Thao, Keith Hawkins, Mackenna L. Wood, Aaron C. Rizzuto, Abderahmane Soubkiou, Benjamin M. Tofflemire, George Zhou, Ian J. M. Crossfield, Logan A. Pearce, Karen A. Collins, Dennis M. Conti, Thiam-Guan Tan, Steven Villeneuva, Alton Spencer, Diana Dragomir, Samuel N. Quinn, Eric L. N. Jensen, Kevin I. Collins, Chris Stockdale, Ryan Cloutier, Coel Hellier, Zouhair Benkhaldoun, Carl Ziegler, César Briceño, Nicholas Law, Björn Benneke, Jessie L. Christiansen, Varoujan Gorjian, Stephen R. Kane, Laura Kreidberg, Farisa Y. Morales, Michael W Werner, Joseph D. Twicken, Alan M. Levine, David R. Ciardi, Natalia M. Guerrero, Katharine Hesse, Elisa V. Quintana, Bernie Shiao, Jeffrey C. Smith, Guillermo Torres, George R. Ricker, Roland Vanderspek, Sara Seager, Joshua N. Winn, Jon M. Jenkins, and David W. Latham
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- 2021
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16. SPYGLASS. II. The Multi-Generational and Multi-Origin Star Formation History of Cepheus Far North
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Ronan Kerr, Adam L. Kraus, Simon J. Murphy, Daniel M. Krolikowski, Stella S. R. Offner, Benjamin M. Tofflemire, and Aaron C. Rizzuto
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Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
Young stellar populations provide a record of past star formation, and by establishing their members' dynamics and ages, it is possible to reconstruct the full history of star formation events. Gaia has greatly expanded the number of accessible stellar populations, with one of the most notable recently-discovered associations being Cepheus Far North (CFN), a population containing hundreds of members spanning over 100 pc. With its proximity (d $\lesssim$ 200 pc), apparent substructure, and relatively small population, CFN represents a manageable population to study in depth, with enough evidence of internal complexity to produce a compelling star formation story. Using Gaia astrometry and photometry combined with additional spectroscopic observations, we identify over 500 candidate CFN members spread across 7 subgroups. Combining ages from isochrones, asteroseismology, dynamics, and lithium depletion, we produce well-constrained ages for all seven subgroups, revealing a largely continuous 10 Myr star formation history in the association. By tracing back the present-day populations to the time of their formation, we identify two spatially and dynamically distinct nodes in which stars form, one associated with $\beta$ Cephei which shows mostly co-spatial formation, and one associated with EE Draconis with a more dispersed star formation history. This detailed view of star formation demonstrates the complexity of the star formation process, even in the smallest of regions., Comment: Accepted to ApJ; 34 pages, 15 figures, 6 tables in two-column AASTEX63 format
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- 2022
17. A Mini-Neptune from TESS and CHEOPS Around the 120 Myr Old AB Dor member HIP 94235
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George Zhou, Christopher P. Wirth, Chelsea X. Huang, Alexander Venner, Kyle Franson, Samuel N. Quinn, L. G. Bouma, Adam L. Kraus, Andrew W. Mann, Elisabeth. R. Newton, Diana Dragomir, Alexis Heitzmann, Nataliea Lowson, Stephanie T. Douglas, Matthew Battley, Edward Gillen, Amaury Triaud, David W. Latham, Steve B. Howell, J. D. Hartman, Benjamin M. Tofflemire, Robert A. Wittenmyer, Brendan P. Bowler, Jonathan Horner, Stephen R. Kane, John Kielkopf, Peter Plavchan, Duncan J. Wright, Brett C. Addison, Matthew W. Mengel, Jack Okumura, George Ricker, Roland Vanderspek, Sara Seager, Jon M. Jenkins, Joshua N. Winn, Tansu Daylan, Michael Fausnaugh, and Michelle Kunimoto
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Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,QB ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The TESS mission has enabled discoveries of the brightest transiting planet systems around young stars. These systems are the benchmarks for testing theories of planetary evolution. We report the discovery of a mini-Neptune transiting a bright star in the AB Doradus moving group. HIP 94235 (TOI-4399, TIC 464646604) is a Vmag=8.31 G-dwarf hosting a 3.00 -0.28/+0.32 Rearth mini-Neptune in a 7.7 day period orbit. HIP 94235 is part of the AB Doradus moving group, one of the youngest and closest associations. Due to its youth, the host star exhibits significant photometric spot modulation, lithium absorption, and X-ray emission. Three 0.06% transits were observed during Sector-27 of the TESS Extended Mission, though these transit signals are dwarfed by the 2% peak-to-peak photometric variability exhibited by the host star. Follow-up observations with CHEOPS confirmed the transit signal and prevented the erosion of the transit ephemeris. HIP 94235 is part of a 50 AU G-M binary system. We make use of diffraction limited observations spanning 11 years, and astrometric accelerations from Hipparchos and Gaia, to constrain the orbit of HIP 94235 B. HIP 94235 is one of the tightest stellar binaries to host an inner planet. As part of a growing sample of bright, young planet systems, HIP 94235 b is ideal for follow-up transit observations, such as those that investigate the evaporative processes driven by high-energy radiation that may sculpt the valleys and deserts in the Neptune population., Accepted for publication in AJ
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- 2022
18. A Low-mass, Pre-main-sequence Eclipsing Binary in the 40 Myr Columba Association -- Fundamental Stellar Parameters and Modeling the Effect of Star Spots
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Benjamin M. Tofflemire, Adam L. Kraus, Andrew W. Mann, Elisabeth R. Newton, Michael A. Gully-Santiago, Andrew Vanderburg, William C. Waalkes, Zachory K. Berta-Thompson, Kevin I. Collins, Karen A. Collins, Louise D. Nielsen, François Bouchy, Carl Ziegler, César Briceño, and Nicholas M. Law
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Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Young eclipsing binaries (EBs) are powerful probes of early stellar evolution. Current models are unable to simultaneously reproduce the measured and derived properties that are accessible for EB systems (e.g., mass, radius, temperature, luminosity). In this study we add a benchmark EB to the pre-main-sequence population with our characterization of TOI 450 (TIC 77951245). Using Gaia astrometry to identify its comoving, coeval companions, we confirm TOI 450 is a member of the $\sim$40 Myr Columba association. This eccentric ($e=0.2969$), equal-mass ($q=1.000$) system provides only one grazing eclipse. Despite this, our analysis achieves the precision of a double-eclipsing system by leveraging information in our high-resolution spectra to place priors on the surface-brightness and radius ratios. We also introduce a framework to include the effect of star spots on the observed eclipse depths. Multicolor eclipse light curves play a critical role in breaking degeneracies between the effects of star spots and limb-darkening. Including star spots reduces the derived radii by $\sim$2\% from an unspotted model ($>2\sigma$) and inflates the formal uncertainty in accordance with our lack of knowledge regarding the star spot orientation. We derive masses of 0.1768($\pm$0.0004) and 0.1767($\pm$0.0003) $M_\odot$, and radii of 0.345($\pm$0.006) and 0.346($\pm$0.006) $R_\odot$ for the primary and secondary, respectively. We compare these measurements to multiple stellar evolution isochones, finding good agreement with the association age. The MESA MIST and SPOTS ($f_{\rm s}=0.17$) isochrones perform the best across our comparisons, but detailed agreement depends heavily on the quantities being compared., Comment: 31 pages, 18 figures, AJ accepted
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- 2022
- Full Text
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19. TESS Hunt for Young and Maturing Exoplanets (THYME) IX: a 27 Myr extended population of Lower-Centaurus Crux with a transiting two-planet system
- Author
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Mackenna L. Wood, Andrew W. Mann, Madyson G. Barber, Jonathan L. Bush, Adam L. Kraus, Benjamin M. Tofflemire, Andrew Vanderburg, Elisabeth R. Newton, Gregory A. Feiden, George Zhou, Luke G. Bouma, Samuel N. Quinn, David J. Armstrong, Ares Osborn, Vardan Adibekyan, Elisa Delgado Mena, Sergio G. Sousa, Jonathan Gagné, Matthew J. Fields, Reilly P. Milburn, Pa Chia Thao, Stephen P. Schmidt, Crystal L. Gnilka, Steve B. Howell, Nicholas M. Law, Carl Ziegler, César Briceño, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Joshua E. Schlieder, Hugh P. Osborn, Joseph D. Twicken, David R. Ciardi, and Chelsea X. Huang
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery and characterization of a nearby (~ 85 pc), older (27 +/- 3 Myr), distributed stellar population near Lower-Centaurus-Crux (LCC), initially identified by searching for stars co-moving with a candidate transiting planet from TESS (HD 109833; TOI 1097). We determine the association membership using Gaia kinematics, color-magnitude information, and rotation periods of candidate members. We measure it's age using isochrones, gyrochronology, and Li depletion. While the association is near known populations of LCC, we find that it is older than any previously found LCC sub-group (10-16 Myr), and distinct in both position and velocity. In addition to the candidate planets around HD 109833 the association contains four directly-imaged planetary-mass companions around 3 stars, YSES-1, YSES-2, and HD 95086, all of which were previously assigned membership in the younger LCC. Using the Notch pipeline, we identify a second candidate transiting planet around HD 109833. We use a suite of ground-based follow-up observations to validate the two transit signals as planetary in nature. HD 109833 b and c join the small but growing population of, 23 pages, 15 figures, Accepted for publication in AJ
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- 2022
- Full Text
- View/download PDF
20. Revealing the Field Sub-subgiant Population Using a Catalog of Active Giant Stars and Gaia EDR3
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Emily M. Leiner, Aaron M. Geller, Michael A. Gully-Santiago, Natalie M. Gosnell, and Benjamin M. Tofflemire
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Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
Sub-subgiant stars (SSGs) fall below the subgiant branch and/or red of the giant branch in open and globular clusters, an area of the color-magnitude diagram (CMD) not populated by standard stellar evolution tracks. One hypothesis is that SSGs result from rapid rotation in subgiants or giants due to tidal synchronization in a close binary. The strong magnetic fields generated inhibit convection, which in turn produces large starspots, radius inflation, and lower-than-expected average surface temperatures and luminosities. Here we cross-reference a catalog of active giant binaries (RS CVns) in the field with Gaia EDR3. Using the Gaia photometry and parallaxes we precisely position the RS CVns in a CMD. We identify stars that fall below a 14 Gyr, metal-rich isochrone as candidate field SSGs. Out of a sample of 1723 RS CVn, we find 448 SSG candidates, a dramatic expansion from the 65 SSGs previously known. Most SSGs have rotation periods of 2-20 days, with the highest SSG fraction found among RS CVn with the shortest periods. The ubiquity of SSGs among this population indicates SSGs are a normal phase in evolution for RS CVn-type systems, not rare by-products of dynamical encounters found only in dense star clusters as some have suggested. We present our catalog of 1723 active giants, including Gaia photometry and astrometry, and rotation periods from TESS and VSX. This catalog can serve as an important sample to study the impacts of magnetic fields in evolved stars., 16 pages, 7 Figures, 1 Table. Accepted for publication in ApJ
- Published
- 2021
21. Characterization of a Solar Mass Eclipsing Binary with TESS and IGRINS
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Mikayla J. Wilson, Benjamin M. Tofflemire, Ronan Kerr, Andrew W. Mann, and Adam L. Kraus
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General Medicine - Abstract
Stellar radius measurements from eclipsing binaries are typically ∼5% larger than standard stellar models predict. This disagreement means we are unable to derive reliable model-dependent radii, which impact stellar and exoplanet characterization. Using light curves from the TESS satellite and high-resolution, near-infrared spectra from IGRINS, we determine the masses and radii of a main sequence eclipsing binary, V1177 Cen (TIC 3099339). We detrend the light curve using a Gaussian process and derive radial velocities using spectral-line broadening functions, fitting both jointly in an MCMC framework. We find that both stars are near 1 M ⊙ with radii 6%–9% larger than the Sun. Based on the absence of Lithium in optical spectra, the inflation is potentially the effect of early post-main sequence evolution, or magnetic fields. We compare our measurement to model isochrones, finding the most consistent agreement with models that include magnetic fields, and correspond to an age of ∼4 Gyr.
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- 2022
22. TESS Hunt for Young and Maturing Exoplanets (THYME) IV: Three small planets orbiting a 120 Myr-old star in the Pisces--Eridanus stream
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Stephen R. Kane, Cesar Briceno, Keith Hawkins, Jessie L. Christiansen, Katharine Hesse, Jon M. Jenkins, Aaron C. Rizzuto, David R. Ciardi, Thiam-Guan Tan, Abderahmane Soubkiou, Logan A. Pearce, Jason L. Curtis, David W. Latham, Zouhair Benkhaldoun, John H. Livingston, Steven Villeneuva, Sara Seager, Nicholas M. Law, Elisabeth R. Newton, Natalia Guerrero, Diana Dragomir, Carl Ziegler, Roland Vanderspek, Joshua N. Winn, Alton Spencer, Ian J. M. Crossfield, Mackenna L. Wood, Coel Hellier, Guillermo Torres, Benjamin M. Tofflemire, Andrew W. Mann, Ryan Cloutier, Andrew Vanderburg, Björn Benneke, Chris Stockdale, George Zhou, Samuel N. Quinn, Dennis M. Conti, Alan M. Levine, Adam L. Kraus, Eric L. N. Jensen, Farisa Y. Morales, Pa Chia Thao, George R. Ricker, Varoujan Gorjian, Kevin I. Collins, Joseph D. Twicken, Jeffrey C. Smith, Michael W. Werner, Karen A. Collins, Laura Kreidberg, Elisa V. Quintana, and Bernie Shiao
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010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Q1 ,01 natural sciences ,Earth radius ,Planet ,0103 physical sciences ,Eridanus ,010303 astronomy & astrophysics ,QC ,Solar and Stellar Astrophysics (astro-ph.SR) ,QB ,0105 earth and related environmental sciences ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Debris disk ,Infrared excess ,Astronomy ,Astronomy and Astrophysics ,Planetary system ,Exoplanet ,Photometry (astronomy) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,QB799 ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Young exoplanets can offer insight into the evolution of planetary atmospheres, compositions, and architectures. We present the discovery of the young planetary system TOI 451 (TIC 257605131, Gaia DR2 4844691297067063424). TOI 451 is a member of the 120-Myr-old Pisces--Eridanus stream (Psc--Eri). We confirm membership in the stream with its kinematics, its lithium abundance, and the rotation and UV excesses of both TOI 451 and its wide binary companion, TOI 451 B (itself likely an M dwarf binary). We identified three candidate planets transiting in the TESS data and followed up the signals with photometry from Spitzer and ground-based telescopes. The system comprises three validated planets at periods of 1.9, 9.2 and 16 days, with radii of 1.9, 3.1, and 4.1 Earth radii, respectively. The host star is near-solar mass with V=11.0 and H=9.3 and displays an infrared excess indicative of a debris disk. The planets offer excellent prospects for transmission spectroscopy with HST and JWST, providing the opportunity to study planetary atmospheres that may still be in the process of evolving., 20 pages, appendix on UV excess
- Published
- 2021
23. TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux
- Author
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Andrew W. Mann, Mackenna L. Wood, Stephen P. Schmidt, Madyson G. Barber, James E. Owen, Benjamin M. Tofflemire, Elisabeth R. Newton, Eric E. Mamajek, Jonathan L. Bush, Gregory N. Mace, Adam L. Kraus, Pa Chia Thao, Andrew Vanderburg, Joe Llama, Christopher M. Johns-Krull, L. Prato, Asa G. Stahl, Shih-Yun Tang, Matthew J. Fields, Karen A. Collins, Kevin I. Collins, Tianjun Gan, Eric L. N. Jensen, Jacob Kamler, Richard P. Schwarz, Elise Furlan, Crystal L. Gnilka, Steve B. Howell, Kathryn V. Lester, Dylan A. Owens, Olga Suarez, Djamel Mekarnia, Tristan Guillot, Lyu Abe, Amaury H. M. J. Triaud, Marshall C. Johnson, Reilly P. Milburn, Aaron C. Rizzuto, Samuel N. Quinn, Ronan Kerr, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Natalia M. Guerrero, Avi Shporer, Joshua E. Schlieder, Brian McLean, Bill Wohler, The Royal Society, and Commission of the European Communities
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0201 Astronomical and Space Sciences ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astronomy & Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Mature super-Earths and sub-Neptunes are predicted to be $\simeq$Jovian radius when younger than 10 Myr. Thus, we expect to find 5-15$R_\oplus$ planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227 b, a $0.85\pm0.05R_J$ (9.5$R_\oplus$) planet transiting a very low-mass star ($0.170\pm0.015M_\odot$) every 27.4 days. TOI~1227's kinematics and strong lithium absorption confirm it is a member of a previously discovered sub-group in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11$\pm$2 Myr for Musca, based on lithium, rotation, and the color-magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5\%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of $\simeq0.5 M_J$. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227 b is still contracting and will eventually turn into one of the more common $, Accepted to the Astronomical Journal. Minor updates during referee process and proofs
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- 2022
24. Disk Material Inflates Gaia RUWE Values in Single Stars
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Shannon Fitton, Benjamin M. Tofflemire, and Adam L. Kraus
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Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics - Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,General Medicine ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
An understanding of the dynamical evolution of binary star systems, and their effects on stellar and planetary evolution, requires well-characterized binary populations across stellar ages. However, the observational resources required to find and characterize binaries are expensive. With the release of high-precision Gaia astrometry, the re-normalized unit weight error (RUWE) statistic has been shown to reveal the presence of binary systems, with RUWE values greater than 1.2 indicating the presence of a stellar companion within $ \sim 1$". Our goal is to assess whether this new diagnostic, which was developed for field-age systems ($>$1 Gyr), applies to young systems; specifically, those that host circumstellar disks. With a control sample of single-star systems, compiled from high-contrast imagining surveys of the Taurus and Upper Scorpius star-forming regions, we compare the RUWE values for systems with and without circumstellar disks. We show that the presence of a protoplanetary disk alone can result in inflated RUWE values. Based on the distribution of the RUWE for disk-bearing single stars, we suggest a more conservative single-star -- binary threshold is warranted in the presence of disk material. We place this cutoff at the distribution's 95th percentile, with RUWE $= 2.5$., 3 pages, 1 figure, RNAAS
- Published
- 2022
25. Observationally Constraining the Starspot Properties of Magnetically Active M67 Sub-subgiant S1063
- Author
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Natalie M. Gosnell, Michael A. Gully-Santiago, Emily M. Leiner, and Benjamin M. Tofflemire
- Subjects
Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
Our understanding of the impact of magnetic activity on stellar evolution continues to unfold. This impact is seen in sub-subgiant stars, defined to be stars that sit below the subgiant branch and red of the main sequence in a cluster color-magnitude diagram. Here we focus on S1063, a prototypical sub-subgiant in open cluster M67. We use a novel technique combining a two-temperature spectral decomposition and light curve analysis to constrain starspot properties over a multi-year time frame. Using a high-resolution near-infrared IGRINS spectrum and photometric data from K2 and ASAS-SN, we find a projected spot filling factor of 32 $\pm$ 7% with a spot temperature of 4000 $\pm$ 200 K. This value anchors the variability seen in the light curve, indicating the spot filling factor of S1063 ranged from 20% to 45% over a four-year time period with an average spot filling factor of 30%. These values are generally lower than those determined from photometric model comparisons but still indicate that S1063, and likely other sub-subgiants, are magnetically active spotted stars. We find observational and theoretical comparisons of spotted stars are nuanced due to the projected spot coverage impacting estimates of the surface-averaged effective temperature. The starspot properties found here are similar to those found in RS CVn systems, supporting classifying sub-subgiants as another type of active giant star binary system. This technique opens the possibility of characterizing the surface conditions of many more spotted stars than previous methods, allowing for larger future studies to test theoretical models of magnetically active stars., Comment: 14 pages, 6 figures, accepted to the Astrophysical Journal
- Published
- 2022
26. TOI 122b and TOI 237b, two small warm planets orbiting inactive M dwarfs, found by \textit{TESS}
- Author
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David R. Ciardi, Emmanuel Jehin, Giovanni Isopi, Robert F. Goeke, K. I. Collins, Jessica E. Libby-Roberts, Bárbara Rojas-Ayala, Jacob L. Bean, Khalid Barkaoui, Francisco J. Pozuelos, M. L. Silverstein, George R. Ricker, David W. Latham, F. Mallia, Joshua N. Winn, Alan M. Levine, William Waalkes, Jessie L. Christiansen, Carl Ziegler, Zachory K. Berta-Thompson, Sara Seager, Elisabeth R. Newton, Joseph D. Twicken, Roland Vanderspek, Tianjun Gan, S. A. Rinehart, Dennis M. Conti, Benjamin M. Tofflemire, Benjamin T. Montet, Karen A. Collins, Michaël Gillon, Mark E. Rose, Adina D. Feinstein, Eric L. N. Jensen, Andrew W. Mann, H. P. Osborn, Nicholas M. Law, Jon M. Jenkins, Cesar Briceno, Eric B. Ting, John F. Kielkopf, and Howard M. Relles
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,01 natural sciences ,Exoplanet ,010309 optics ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Planet ,0103 physical sciences ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery and validation of TOI 122b and TOI 237b, two warm planets transiting inactive M dwarfs observed by \textit{TESS}. Our analysis shows TOI 122b has a radius of 2.72$\pm$0.18 R$_\rm{e}$ and receives 8.8$\pm$1.0$\times$ Earth's bolometric insolation, and TOI 237b has a radius of 1.44$\pm$0.12 R$_\rm{e}$ and receives 3.7$\pm$0.5$\times$ Earth insolation, straddling the 6.7$\times$ Earth insolation that Mercury receives from the sun. This makes these two of the cooler planets yet discovered by \textit{TESS}, even on their 5.08-day and 5.43-day orbits. Together, they span the small-planet radius valley, providing useful laboratories for exploring volatile evolution around M dwarfs. Their relatively nearby distances (62.23$\pm$0.21 pc and 38.11$\pm$0.23 pc, respectively) make them potentially feasible targets for future radial velocity follow-up and atmospheric characterization, although such observations may require substantial investments of time on large telescopes., Comment: 21 pages, 9 figures, 4 tables, accepted to AJ
- Published
- 2020
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27. Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary
- Author
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Robert D. Mathieu, Christopher M. Johns-Krull, and Benjamin M. Tofflemire
- Subjects
010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,0103 physical sciences ,Binary star ,Astrophysics::Solar and Stellar Astrophysics ,Emission spectrum ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Star formation ,Astronomy and Astrophysics ,Accretion (astrophysics) ,T Tauri star ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Precession ,H-alpha ,Astrophysics::Earth and Planetary Astrophysics ,Circumbinary planet ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present time-series, high-resolution optical spectroscopy of the eccentric T Tauri binary TWA 3A. Our analysis focuses on variability in the strength and structure of the accretion tracing emission lines H alpha and He I 5876A. We find emission line strengths to display the same orbital-phase dependent behavior found with time-series photometry, namely, bursts of accretion near periastron passages. Such bursts are in good agreement with numerical simulations of young eccentric binaries. During accretion bursts, the emission of He I 5876A consistently traces the velocity of the primary star. After removing a model for the system's chromospheric emission, we find the primary star typically emits ~70% of the He I accretion flux. We interpret this result as evidence for circumbinary accretion streams that preferentially feed the TWA 3A primary. This finding is in contrast to most numerical simulations, which predict the secondary should be the dominant accretor in a binary system. Our results may be consistent with a model in which the precession of an eccentric circumbinary disk gap alternates between preferentially supplying mass to the primary and secondary., 29 pages, 16 figures, AJ, accepted
- Published
- 2019
28. The IGRINS YSO Survey II: Veiling Spectra of Pre-main-sequence Stars in Taurus-Auriga
- Author
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Miguel Gutiérrez, Benjamin M. Tofflemire, Victoria E. Catlett, Ricardo López-Valdivia, Kimberly R. Sokal, Benjamin Kidder, Gregory N. Mace, and Daniel T. Jaffe
- Subjects
Physics ,AURIGA ,Space and Planetary Science ,Astronomy and Astrophysics ,Astrophysics ,Main sequence ,Spectral line - Abstract
We present measurements of the H- and K-band veiling for 141 young stellar objects (YSOs) in the Taurus-Auriga star-forming region using high-resolution spectra from the Immersion Grating Near-Infrared Spectrometer. In addition to providing measurements of r H and r K , we produce low-resolution spectra of the excess emission across the H and K bands. We fit temperatures to the excess spectra of 46 members of our sample and measure near-infrared excess temperatures ranging from 1200–2200 K, with an average of 1575 ± 225 K. We compare the luminosity of the excess continuum emission in Class II and Class III YSOs and find that a number of Class III sources display a significant amount of excess flux in the near-infrared. We conclude that the mid-infrared SED slope, and therefore young stellar object classification, is a poor predictor of the amount of near-infrared veiling. If the veiling arises in thermal emission from dust, its presence implies a significant amount of remaining inner-disk (H-band excess spectra that is consistent with veiling from cool photospheric spots.
- Published
- 2021
29. TESS Hunt for Young and Maturing Exoplanets (THYME): A Planet in the 45 Myr Tucana–Horologium Association
- Author
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Jon M. Jenkins, Steven Villeneuva, Mackenna L. Wood, Coel Hellier, Luke G. Bouma, John F. Kielkopf, Sara Seager, Jason J. Wang, Joseph E. Rodriguez, Christopher J. Burke, Thomas Barclay, Raquel A. Martinez, Joel Villasenor, Robert L. Morris, Adam L. Kraus, Pa Chia Thao, Gregory A. Feiden, Andrew W. Mann, Karen A. Collins, Eric L. Nielsen, Andrew Vanderburg, Robert J. De Rosa, Robert A. Wittenmyer, Misty Davies, Matthew W. Mengel, Jie Li, Chris Stockdale, Jack Okumura, Aaron C. Rizzuto, Logan A. Pearce, Jack J. Lissauer, David W. Latham, Rhodes Hart, Joshua N. Winn, Bruce Macintosh, Duncan J. Wright, Diana Dragomir, Koji Mukai, Rayna Rampalli, George R. Ricker, F. Mallia, Marshall C. Johnson, David R. Anderson, Jean-Baptiste Ruffio, Roland Vanderspek, Carolyn Brown, Peter F. Nelson, Giovanni Isopi, Benjamin M. Tofflemire, Ian A. Waite, Elisabeth R. Newton, and Michael Fausnaugh
- Subjects
010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Photometry (optics) ,Neptune ,Planet ,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 ,Visual binary ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astronomy and Astrophysics ,Planetary system ,Orbital period ,Exoplanet ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Earth and Planetary Astrophysics ,QB799 - Abstract
Young exoplanets are snapshots of the planetary evolution process. Planets that orbit stars in young associations are particularly important because the age of the planetary system is well constrained. We present the discovery of a transiting planet larger than Neptune but smaller than Saturn in the 45 Myr Tucana-Horologium young moving group. The host star is a visual binary, and our follow-up observations demonstrate that the planet orbits the G6V primary component, DS Tuc A (HD 222259A, TIC 410214986). We first identified transits using photometry from the Transiting Exoplanet Survey Satellite (TESS; alerted as TOI 200.01). We validated the planet and improved the stellar parameters using a suite of new and archival data, including spectra from SOAR/Goodman, SALT/HRS and LCO/NRES; transit photometry from Spitzer; and deep adaptive optics imaging from Gemini/GPI. No additional stellar or planetary signals are seen in the data. We measured the planetary parameters by simultaneously modeling the photometry with a transit model and a Gaussian process to account for stellar variability. We determined that the planetary radius is $5.70\pm0.17$ Earth radii and that the orbital period is 8.1 days. The inclination angles of the host star's spin axis, the planet's orbital axis, and the visual binary's orbital axis are aligned within 15 degrees to within the uncertainties of the relevant data. DS Tuc Ab is bright enough (V=8.5) for detailed characterization using radial velocities and transmission spectroscopy., Accepted to ApJ Letters 2019 June 11
- Published
- 2019
30. Close companions around young stars
- Author
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Penélope Longa-Peña, Adam L. Kraus, Benjamin M. Tofflemire, Maxwell Moe, Cody Brown, Audrey Oravetz, Kaike Pan, J. Borissova, Daniel Oravetz, Nathan De Lee, Keivan G. Stassun, Guy S. Stringfellow, Kevin R. Covey, Yilen Gómez Maqueo Chew, Karla Peña Ramírez, Jesús Hernández, Rodolfo H. Barbá, Daniel M. Krolikowski, Dmitry Bizyaev, Carlos Román-Zúñiga, Alexandre Roman-Lopes, David L. Nidever, Aaron C. Rizzuto, Genaro Suárez, Carles Badenes, Karl O. Jaehnig, Jinyoung Serena Kim, Kaitlin M. Kratter, and Marina Kounkel
- Subjects
010504 meteorology & atmospheric sciences ,Library science ,FOS: Physical sciences ,Astronomy and Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Christian ministry ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Mathematics - Abstract
Multiplicity is a fundamental property that is set early during stellar lifetimes, and it is a stringent probe of the physics of star formation. The distribution of close companions around young stars is still poorly constrained by observations. We present an analysis of stellar multiplicity derived from APOGEE-2 spectra obtained in targeted observations of nearby star-forming regions. This is the largest homogeneously observed sample of high-resolution spectra of young stars. We developed an autonomous method to identify double lined spectroscopic binaries (SB2s). Out of 5007 sources spanning the mass range of $\sim$0.05--1.5 \msun, we find 399 binaries, including both RV variables and SB2s. The mass ratio distribution of SB2s is consistent with a uniform for $q0.95$. The period distribution is consistent with what has been observed in close binaries ($, 25 pages, 20 figures. Accepted to AJ
- Published
- 2019
31. TESS Hunt for Young and Maturing Exoplanets (THYME). V. A Sub-Neptune Transiting a Young Star in a Newly Discovered 250 Myr Association
- Author
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Richard P. Schwarz, Brian McLean, Tyler Nelson, Joshua N. Winn, Bill Wohler, Aaron C. Rizzuto, Karen Collins, Benjamin M. Tofflemire, Andrew W. Mann, Andrew Vanderburg, Keith Hawkins, David W. Latham, Steve B. Howell, Zahra Essack, Mackenna L. Wood, Keivan G. Stassun, Ana Glidden, Hugh P. Osborn, Patricia T. Boyd, George Zhou, Gábor Fűrész, Roland Vanderspek, George R. Ricker, Samuel N. Quinn, Elisabeth R. Newton, Joseph D. Twicken, Luke G. Bouma, Jon M. Jenkins, Sara Seager, and Adam L. Kraus
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,FOS: Physical sciences ,Astronomy ,myr ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Exoplanet ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Young star ,Neptune ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The detection and characterization of young planetary systems offers a direct path to study the processes that shape planet evolution. We report on the discovery of a sub-Neptune-size planet orbiting the young star HD 110082 (TOI-1098). Transit events we initially detected during TESS Cycle 1 are validated with time-series photometry from Spitzer. High-contrast imaging and high-resolution, optical spectra are also obtained to characterize the stellar host and confirm the planetary nature of the transits. The host star is a late F dwarf (M=1.2 Msun) with a low-mass, M dwarf binary companion (M=0.26 Msun) separated by nearly one arcminute (~6200 AU). Based on its rapid rotation and Lithium absorption, HD 110082 is young, but is not a member of any known group of young stars (despite proximity to the Octans association). To measure the age of the system, we search for coeval, phase-space neighbors and compile a sample of candidate siblings to compare with the empirical sequences of young clusters and to apply quantitative age-dating techniques. In doing so, we find that HD 110082 resides in a new young stellar association we designate MELANGE-1, with an age of 250(+50/-70) Myr. Jointly modeling the TESS and Spitzer light curves, we measure a planetary orbital period of 10.1827 days and radius of Rp = 3.2(+/-0.1) Earth radii. HD 110082 b's radius falls in the largest 12% of field-age systems with similar host star mass and orbital period. This finding supports previous studies indicating that young planets have larger radii than their field-age counterparts., Comment: Accepted to AJ, 20 figures, 7 tables, 1 appendix
- Published
- 2021
32. WIYN Open Cluster Study. LXXXII. Radial-velocity Measurements and Spectroscopic Binary Orbits in the Open Cluster NGC 7789
- Author
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Katelyn E. Milliman, Robert D. Mathieu, Emily M. Leiner, Imants Platais, Aaron M. Geller, Andrew C. Nine, and Benjamin M. Tofflemire
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,010308 nuclear & particles physics ,FOS: Physical sciences ,Binary number ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Radial velocity ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Binary star ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics ,Open cluster - Abstract
We introduce the stellar sample of the WIYN Open Cluster Study radial-velocity survey for the rich open cluster NGC 7789 (1.6 Gyr, [Fe/H] = +0.02). This sample lies within an 18$'$ circular radius from the cluster center (10 pc in projection, or about 2 core radii), and includes giants, red-clump stars, blue stragglers, red stragglers, sub-subgiants, and main-sequence stars down to one mag below the turnoff. Our survey began in 2005 and comprises more than 9,000 radial-velocity measurements from the Hydra Multi-Object Spectrograph on the WIYN 3.5m telescope. We identify 564 likely cluster members and present the orbital solutions for 83 cluster binary stars with periods between 1.45$\,$d and 4200$\,$d. From the main-sequence binary solutions we fit a circularization period of 8.22$^{+3.51}_{-1.35}\,$d. We calculate an incompleteness-corrected main-sequence binary frequency of 31% $\pm$ 3% for binaries with periods less than 10$^{4}$ days, similar to other WOCS open clusters of all ages. We detect a blue straggler binary frequency of 31% $\pm$ 15%, consistent with the similarly aged cluster NGC 6819., 47 pages, 16 figures. Submitted to AJ
- Published
- 2020
33. TESS Hunt for Young and Maturing Exoplanets (THYME). II. A 17 Myr Old Transiting Hot Jupiter in the Sco-Cen Association
- Author
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Pa Chia Thao, Aaron C. Rizzuto, Samuel N. Quinn, Adam L. Kraus, Andrew Vanderburg, Nicholas M. Law, Elisabeth R. Newton, Carl Ziegler, Mackenna L. Wood, Andrew W. Mann, Cesar Briceno, Benjamin M. Tofflemire, and George Zhou
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Orbital period ,01 natural sciences ,Exoplanet ,Radial velocity ,Photometry (astronomy) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,Transit (astronomy) ,010303 astronomy & astrophysics ,Stellar evolution ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics ,0105 earth and related environmental sciences - Abstract
We present the discovery of a transiting hot Jupiter orbiting HIP 67522 ($T_{eff}\sim5650$ K; $M_* \sim 1.2 M_{\odot}$) in the 10-20 Myr old Sco-Cen OB association. We identified the transits in the TESS data using our custom notch-filter planet search pipeline, and characterize the system with additional photometry from Spitzer, spectroscopy from SOAR/Goodman, SALT/HRS, LCOGT/NRES, and SMARTS/CHIRON, and speckle imaging from SOAR/HRCam. We model the photometry as a periodic Gaussian process with transits to account for stellar variability, and find an orbital period of 6.9596$^{+0.000016}_{-0.000015}$ days and radius of 10.02$^{+0.54}_{-0.53}$ R$_\oplus$. We also identify a single transit of an additional candidate planet with radius 8.01$^{+0.75}_{-0.71}$ R$_\oplus$ that has an orbital period of $\gtrsim23$ days. The validated planet HIP 67522 b is currently the youngest transiting hot Jupiter discovered and is an ideal candidate for transmission spectroscopy and radial velocity follow-up studies, while also demonstrating that some young giant planets either form in situ at small orbital radii, or else migrate promptly from formation sites farther out in the disk., Submitted to AAS Journals, 19 pages, 10 figures, 6 tables
- Published
- 2020
34. Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of Gaia
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Andrew Vanderburg, Benjamin M. Tofflemire, Trent J. Dupuy, Adam L. Kraus, Elisabeth R. Newton, Andrew W. Mann, and Logan A. Pearce
- Subjects
010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics ,01 natural sciences ,Planet ,0103 physical sciences ,Binary star ,Astrophysics::Solar and Stellar Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Orbital elements ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Astrometry ,Planetary system ,Orbit ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Orbit determination ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The orbits of binary stars and planets, particularly eccentricities and inclinations, encode the angular momentum within these systems. Within stellar multiple systems, the magnitude and (mis)alignment of angular momentum vectors among stars, disks, and planets probes the complex dynamical processes guiding their formation and evolution. The accuracy of the \textit{Gaia} catalog can be exploited to enable comparison of binary orbits with known planet or disk inclinations without costly long-term astrometric campaigns. We show that \textit{Gaia} astrometry can place meaningful limits on orbital elements in cases with reliable astrometry, and discuss metrics for assessing the reliability of \textit{Gaia} DR2 solutions for orbit fitting. We demonstrate our method by determining orbital elements for three systems (DS Tuc AB, GK/GI Tau, and Kepler-25/KOI-1803) using \textit{Gaia} astrometry alone. We show that DS Tuc AB's orbit is nearly aligned with the orbit of DS Tuc Ab, GK/GI Tau's orbit might be misaligned with their respective protoplanetary disks, and the Kepler-25/KOI-1803 orbit is not aligned with either component's transiting planetary system. We also demonstrate cases where \textit{Gaia} astrometry alone fails to provide useful constraints on orbital elements. To enable broader application of this technique, we introduce the python tool \texttt{lofti\_gaiaDR2} to allow users to easily determine orbital element posteriors., Comment: 18 pages, 10 figures, accepted for publication in ApJ
- Published
- 2020
35. Constraining Temperature and Density of Accretion Flows in T Tauri Stars from Brackett Line Ratios
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Gregory N. Mace, Adam L. Kraus, Victoria E. Catlett, Benjamin M. Tofflemire, and Miguel Gutiérrez
- Subjects
Physics ,T Tauri star ,General Medicine ,Astrophysics ,Accretion (astrophysics) ,Line (formation) - Published
- 2020
36. Near-infrared Accretion Diagnostics of Young Stellar Objects
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Benjamin Kidder, Adam L. Kraus, Miguel Gutiérrez, Gregory N. Mace, Victoria E. Catlett, and Benjamin M. Tofflemire
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Physics ,Young stellar object ,Near-infrared spectroscopy ,General Medicine ,Astrophysics ,Accretion (astrophysics) - Published
- 2019
37. WIYN Open Cluster Study. LXXI. Spectroscopic Membership and Orbits of NGC 6791 Sub-Subgiants
- Author
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Robert D. Mathieu, Emily Leiner, Benjamin M. Tofflemire, Imants Platais, and Katelyn E. Milliman
- Subjects
Physics ,Orbital elements ,010504 meteorology & atmospheric sciences ,Binary number ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Luminosity ,Red-giant branch ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0103 physical sciences ,Cluster (physics) ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Stellar evolution ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Open cluster - Abstract
In an optical color-magnitude diagram sub-subgiants (SSGs) lie red of the main sequence and fainter than the base of the red giant branch in a region not easily populated by standard stellar-evolution pathways. In this paper, we present multi-epoch radial velocities for five SSG candidates in the old and metal-rich open cluster NGC 6791 (8 Gyr, [Fe/H] = +0.30). From these data we are able to make three-dimensional kinematic membership determinations and confirm four SSG candidates to be likely cluster members. We also identify three member SSGs as short-period binary systems and present their orbital solutions. These are the first SSGs with known three-dimensional kinematic membership, binary status, and orbital parameters since the two SSGs in M67 studied by Mathieu et al. 2003. We also remark on the other properties of these stars including photometric variability, H$\alpha$ emission, and X-ray luminosity. The membership confirmation of these SSGs in NGC 6791 strengthens the case that SSGs are a new class of nonstandard stellar evolution products, and that a physical mechanism must be found that explains the evolutionary paths of these stars., Comment: 11 pages, 7 figures
- Published
- 2016
- Full Text
- View/download PDF
38. Pulsed Accretion in the T Tauri Binary TWA 3A
- Author
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David R. Ciardi, Gregory J. Herczeg, Rachel Akeson, Robert D. Mathieu, and Benjamin M. Tofflemire
- Subjects
Orbital elements ,Physics ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Binary number ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Accretion (astrophysics) ,T Tauri star ,Amplitude ,Astrophysics - Solar and Stellar Astrophysics ,Accretion disc ,Space and Planetary Science ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Circumbinary planet ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Order of magnitude - Abstract
TWA 3A is the most recent addition to a small group of young binary systems that both actively accrete from a circumbinary disk and have spectroscopic orbital solutions. As such, it provides a unique opportunity to test binary accretion theory in a well-constrained setting. To examine TWA 3A's time-variable accretion behavior, we have conducted a two-year, optical photometric monitoring campaign, obtaining dense orbital phase coverage (~20 observations per orbit) for ~15 orbital periods. From U-band measurements we derive the time-dependent binary mass accretion rate, finding bursts of accretion near each periastron passage. On average, these enhanced accretion events evolve over orbital phases 0.85 to 1.05, reaching their peak at periastron. The specific accretion rate increases above the quiescent value by a factor of ~4 on average but the peak can be as high as an order of magnitude in a given orbit. The phase dependence and amplitude of TWA 3A accretion is in good agreement with numerical simulations of binary accretion with similar orbital parameters. In these simulations, periastron accretion bursts are fueled by periodic streams of material from the circumbinary disk that are driven by the binary orbit. We find that TWA 3A's average accretion behavior is remarkably similar to DQ Tau, another T Tauri binary with similar orbital parameters, but with significantly less variability from orbit to orbit. This is only the second clear case of orbital-phase-dependent accretion in a T Tauri binary., 6 pages, 4 figures
- Published
- 2017
39. WIYN Open Cluster Study. LIX. Radial-Velocity Membership of the Evolved Population of the Old Open Cluster NGC 6791
- Author
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Imants Platais, Natalie M. Gosnell, Benjamin M. Tofflemire, and Robert D. Mathieu
- Subjects
Physics ,Proper motion ,010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Horizontal branch ,01 natural sciences ,Blue straggler ,Red-giant branch ,Radial velocity ,Star cluster ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0103 physical sciences ,010303 astronomy & astrophysics ,Red clump ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Open cluster - Abstract
The open cluster NGC 6791 has been the focus of much recent study due to its intriguing combination of old age and high metallicity ($\sim$8 Gyr, [Fe$/$H]=$+$0.30), as well as its location within the Kepler field. As part of the WIYN Open Cluster Study, we present precise ($\sigma=0.38$ km s$^{-1}$) radial velocities for proper-motion candidate members of NGC 6791 from Platais et al. Our survey, extending down to $g^\prime\sim16.8$, is comprised of the evolved cluster population, including blue stragglers, giants, and horizontal branch stars. Of the 280 proper-motion-selected stars above our magnitude limit, 93% have at least one radial-velocity measurement and 79% have three measurements over the course of at least 200 days, sufficient for secure radial-velocity-determined membership of non-velocity-variable stars. The Platais et al. proper-motion catalog includes twelve anomalous horizontal branch candidates blueward of the red clump, of which we find only four to be cluster members. Three fall slightly blueward of the red clump and the fourth is consistent with being a blue straggler. The cleaned color-magnitude diagram shows a richly populated red giant branch and a blue straggler population. Half of the blue stragglers are in binaries. From our radial-velocity measurement distribution we find the cluster's radial-velocity dispersion to be $\sigma_c=0.62\pm0.10$ km s$^{-1}$. This corresponds to a dynamical mass of $\sim$4600 $M_\odot$., Comment: Accepted to The Astrophysical Journal July 28th, 2014. 12 pages, 8 figures, 5 tables
- Published
- 2014
40. A Cautionary Tale: MARVELS Brown Dwarf Candidate Reveals Itself To Be A Very Long Period, Highly Eccentric Spectroscopic Stellar Binary
- Author
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Arpita Roy, Stephen R. Kane, Leslie Hebb, B. Scott Gaudi, Kaike Pan, Jonay I. González Hernández, Stephanie A. Snedden, Luan Ghezzi, Rohit Deshpande, Carlos Allende Prieto, Massimiliano Esposito, Benjamin M. Tofflemire, Phillip Cargile, Daniel Oravetz, Robert J. Siverd, Rafael Rebolo, Audrey Simmons, Martin Paegert, Eric Agol, Thomas G. Beatty, Brian C. Lee, Claude E. Mack, Peng Jiang, Elena Malanushenko, Nathan De Lee, V. Malanushenko, Keivan G. Stassun, Daniel Mata Sánchez, John P. Wisniewski, Luiz N. da Costa, Dmitry Bizyaev, Howard Brewington, Gustavo F. Porto de Mello, Justin R. Crepp, Joshua Peper, Suvrath Mahadevan, Scott W. Fleming, Bruno Femenia, Donald P. Schneider, Jian Ge, G. Ebelke, Jason D. Eastman, Marcio A. G. Maia, Leticia D. Ferreira, and Basilio X. Santiago
- Subjects
010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,Brown dwarf ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,spectroscopic [Binaries] ,0103 physical sciences ,Binary star ,Astrophysics::Solar and Stellar Astrophysics ,Circular orbit ,Eccentricity (behavior) ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,media_common ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Orbital elements ,individual (TYC 3010-1494-1) [Stars] ,Line-of-sight ,Brown dwarfs ,Astronomy and Astrophysics ,Stars ,Orbit ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Anãs marrons ,Astrophysics::Earth and Planetary Astrophysics ,Estrelas binarias ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the discovery of a highly eccentric, double-lined spectroscopic binary star system (TYC 3010-1494-1), comprising two solar-type stars that we had initially identified as a single star with a brown dwarf companion. At the moderate resolving power of the MARVELS spectrograph and the spectrographs used for subsequent radial-velocity (RV) measurements (R ~, 16 pages, 11 figures, 6 tables
- Published
- 2013
41. X-Ray Grating Observations of Recurrent Nova T Pyxidis During The 2011 Outburst
- Author
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K. L. Page, Valentina Cracco, Francesco Di Mille, M. P. Maxwell, J. P. Osborne, Benjamin M. Tofflemire, Stefano Ciroi, and Marina Orio
- Subjects
Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Doubly ionized oxygen ,White dwarf ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,stars:individual:TPxidis ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Effective temperature ,Spectral line ,Novae ,Cataclysmic Variables ,Full width at half maximum ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics::Solar and Stellar Astrophysics ,Emission spectrum ,Southern African Large Telescope ,Ejecta ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
The recurrent nova T Pyx was observed with the X-ray gratings of Chandra and XMM-Newton, 210 and 235 days, respectively, after the discovery of the 2011 April 14 outburst. The X-ray spectra show prominent emission lines of C, N, and O, with broadening corresponding to a full width at half maximum of ~2000-3000 km/s, and line ratios consistent with high-density plasma in collisional ionization equilibrium. On day 210 we also measured soft X-ray continuum emission that appears to be consistent with a white dwarf (WD) atmosphere at a temperature ~420,000 K, partially obscured by anisotropic, optically thick ejecta. The X-ray continuum emission is modulated with the photometric and spectroscopic period observed in quiescence. The continuum at day 235 indicated a WD atmosphere at a consistent effective temperature of 25 days earlier, but with a lower flux. The effective temperature indicates a mass of ~1 solar mass. The conclusion of partial WD obscuration is supported by the complex geometry of non-spherically-symmetric ejecta confirmed in recent optical spectra obtained with the Southern African Large Telescope (SALT) in November and December of 2012. These spectra exhibited prominent [O III] nebular lines with velocity structures typical of bipolar ejecta., Comment: Accepted to ApJ 2013 October 23, 14 pages, 9 figures, 3 tables
- Published
- 2013
- Full Text
- View/download PDF
42. Very Low-Mass Stellar and Substellar Companions to Solar-Like Stars from MARVELS I: A Low Mass Ratio Stellar Companion to TYC 4110-01037-1 in a 79-day Orbit
- Author
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Marcio A. G. Maia, Jon Holtzman, Jian Ge, Luan Ghezzi, Rafael Rebolo, Ricardo L. C. Ogando, Brian L. Lee, Keivan G. Stassun, Eric Agol, Jonay I. González Hernández, Kaike Pan, Claude E. Mack, Joshua Pepper, Phillip A. Cargile, Luiz N. da Costa, Leslie Hebb, Jason D. Eastman, Bruno Femenia, B. Scott Gaudi, Duy Cuong Nguyen, G. F. Porto de Mello, Bo Zhao, Suvrath Mahadevan, Basilio X. Santiago, Bo Ma, Benjamin M. Tofflemire, Justin R. Crepp, Donald P. Schneider, Rory Barnes, Jian Liu, Daniel Oravetz, Xiaoke Wan, Carlos Allende Prieto, Ji Wang, John P. Wisniewski, Dmitry Bizyaev, Bruce Gary, Alaina Shelden, Leticia D. Ferreira, Audrey Simmons, Massimiliano Esposito, Martin Paegert, Nathan De Lee, Liang Chang, and Scott W. Fleming
- Subjects
Physics ,High contrast ,010504 meteorology & atmospheric sciences ,Brown dwarf ,FOS: Physical sciences ,Astronomy and Astrophysics ,Context (language use) ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Mass ratio ,Orbital period ,01 natural sciences ,Orbit ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Low Mass ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences - Abstract
TYC 4110-01037-1 has a low-mass stellar companion, whose small mass ratio and short orbital period are atypical amongst solar-like (Teff ~< 6000 K) binary systems. Our analysis of TYC 4110-01037-1 reveals it to be a moderately aged (~0.087 +/- 0.003, places it at the lowest end of observed values for short period stellar companions to solar-like (Teff ~< 6000 K) stars. One possible way to create such a system would be if a triple-component stellar multiple broke up into a short period, low q binary during the cluster dispersal phase of its lifetime. A candidate tertiary body has been identified in the system via single-epoch, high contrast imagery. If this object is confirmed to be co-moving, we estimate it would be a dM4 star. We present these results in the context of our larger-scale effort to constrain the statistics of low mass stellar and brown dwarf companions to FGK-type stars via the MARVELS survey., 22 pages; accepted in AJ
- Published
- 2012
43. Very low mass stellar and substellar companions to solar-like stars from MARVELS. II. A short-period companios orbiting an F star with evidence of a stellar tertiary and significant mutual inclination
- Author
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Eric J. Roebuck, Carlos Allende Prieto, Ji Wang, Rafael Rebolo, Gwendolyn M. Weaver, Eric Agol, Louis Coban, Howard Brewington, Joshua Pepper, Duy Cuong Nguyen, Audrey Simmons, Jian Liu, Xiaoke Wan, Daniel Oravetz, Peng Jiang, B. Scott Gaudi, Martin Paegert, Luan Ghezzi, Stephen R. Kane, Elena Malanushenko, W. Michael Wood-Vasey, Nathan De Lee, Rory Barnes, Thomas G. Beatty, Chelsea L. M. Vincent, Bo Ma, Alaina Shelden, John P. Wisniewski, Marcio A. G. Maia, Brian Lee, Jian Ge, Donald P. Schneider, Nelson Hua, Kaike Pan, Jonay I. González Hernández, Stephanie A. Snedden, Demitri Muna, Bo Zhao, B. E. Nelson, Luis N. da Costa, Bruce Gary, Justin R. Crepp, Phillip A. Cargile, Massimiliano Esposito, Benjamin J. Shappee, Dmitry Bizyaev, Suvrath Mahadevan, Leslie Hebb, Benjamin A. Weaver, Korena S. Costello, Bruno Femenia, Keivan G. Stassun, Benjamin M. Tofflemire, Gustavo F. Porto de Mello, Thirupathi Sivarani, Scott W. Fleming, Viktor Malanushenko, Leticia D. Ferreira, Gary R. Lander, Todd A. Thompson, Basilio X. Santiago, and Melanie Good
- Subjects
010504 meteorology & atmospheric sciences ,Stellar mass ,Astrometria ,Momento angular ,FOS: Physical sciences ,Hidrogênio ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Compact star ,Massa estelar ,01 natural sciences ,Movimento estelar ,spectroscopic [Binaries] ,individual (TYC 2930-00872-1) [Stars] ,0103 physical sciences ,Evolucao estelar ,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 ,Cálcio ,Astronomy and Astrophysics ,Orbital period ,Espectros estelares ,Radial velocity ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Potássio ,Spectral energy distribution ,Astrophysics::Earth and Planetary Astrophysics ,Low Mass ,Dimensões estelares ,close [Binaries] ,Main sequence - Abstract
We report the discovery via radial velocity of a short-period (P = 2.430420 \pm 0.000006 days) companion to the F-type main sequence star TYC 2930-00872-1. A long-term trend in the radial velocities indicates the presence of a tertiary stellar companion with $P > 2000$ days. High-resolution spectroscopy of the host star yields T_eff = 6427 +/- 33 K, log(g) = 4.52 +/- 0.14, and [Fe/H]=-0.04 +/- 0.05. These parameters, combined with the broad-band spectral energy distribution and parallax, allow us to infer a mass and radius of the host star of M_1=1.21 +/- 0.08 M_\odot and R_1=1.09_{-0.13}^{+0.15} R_\odot. We are able to exclude transits of the inner companion with high confidence. The host star's spectrum exhibits clear Ca H and K core emission indicating stellar activity, but a lack of photometric variability and small v*sin(I) suggest the primary's spin axis is oriented in a pole-on configuration. The rotational period of the primary from an activity-rotation relation matches the orbital period of the inner companion to within 1.5 ��, suggesting they are tidally locked. If the inner companion's orbital angular momentum vector is aligned with the stellar spin axis, as expected through tidal evolution, then it has a stellar mass of M_2 ~ 0.3-0.4 M_\odot. Direct imaging limits the existence of stellar companions to projected separations < 30 AU. No set of spectral lines and no significant flux contribution to the spectral energy distribution from either companion are detected, which places individual upper mass limits of M < 1.0 M_\odot, provided they are not stellar remnants. If the tertiary is not a stellar remnant, then it likely has a mass of ~0.5-0.6 M_\odot, and its orbit is likely significantly inclined from that of the secondary, suggesting that the Kozai-Lidov mechanism may have driven the dynamical evolution of this system., 37 pages, 7 tables, 21 figures, Accepted in AJ
- Published
- 2012
44. PDS 144: The First Confirmed Herbig Ae - Herbig Ae Wide Binary
- Author
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Kenza S. Arraki, Carol A. Grady, David Bonfield, John P. Wisniewski, Kenji Hamaguchi, Benjamin M. Tofflemire, Robert Petre, Marshall D. Perrin, Jon Holtzman, Bruce E. Woodgate, Norman A. Grogin, James T. Lauroesch, B. Daly, Jeremy Hornbeck, Gerard M. Williger, Alexander Brown, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,Proper motion ,010504 meteorology & atmospheric sciences ,Star formation ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Radial velocity ,Interstellar medium ,Stars ,T Tauri star ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,0103 physical sciences ,Binary star ,Herbig–Haro object ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences - Abstract
PDS 144 is a pair of Herbig Ae stars that are separated by 5.35" on the sky. It has previously been shown to have an A2Ve Herbig Ae star viewed at 83\circ inclination as its northern member and an A5Ve Herbig Ae star as its southern member. Direct imagery revealed a disk occulting PDS 144 N - the first edge-on disk observed around a Herbig Ae star. The lack of an obvious disk in direct imagery suggested PDS 144 S might be viewed face-on or not physically associated with PDS 144 N. Multi-epoch Hubble Space Telescope imagery of PDS 144 with a 5 year baseline demonstrates PDS 144 N & S are comoving and have a common proper motion with TYC 6782-878-1. TYC 6782-878-1 has previously been identified as a member of Upper Sco sub-association A at d = 145 \pm 2 pc with an age of 5-10 Myr. Ground-based imagery reveals jets and a string of Herbig-Haro knots extending 13' (possibly further) which are aligned to within 7\circ \pm 6\circ on the sky. By combining proper motion data and the absence of a dark mid-plane with radial velocity data, we measure the inclination of PDS 144 S to be i = 73\circ \pm 7\circ. The radial velocity of the jets from PDS 144 N & S indicates they, and therefore their disks, are misaligned by 25\circ \pm 9\circ. This degree of misalignment is similar to that seen in T Tauri wide binaries., 18 pages, 5 figures, 2 tables
- Published
- 2011
45. The Implications of M Dwarf Flares on the Detection and Characterization of Exoplanets at Infrared Wavelengths
- Author
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Jon Holtzman, Praveen Kundurthy, Sarah J. Schmidt, Suzanne L. Hawley, Benjamin M. Tofflemire, John P. Wisniewski, Eric J. Hilton, and Adam F. Kowalski
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Infrared ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Exoplanet ,Spectral line ,law.invention ,Photometry (optics) ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Planet ,law ,Solar and Stellar Astrophysics (astro-ph.SR) ,Line (formation) ,Flare ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present the results of an observational campaign which obtained high time cadence, high precision, simultaneous optical and IR photometric observations of three M dwarf flare stars for 47 hours. The campaign was designed to characterize the behavior of energetic flare events, which routinely occur on M dwarfs, at IR wavelengths to milli-magnitude precision, and quantify to what extent such events might influence current and future efforts to detect and characterize extrasolar planets surrounding these stars. We detected and characterized four highly energetic optical flares having U-band total energies of ~7.8x10^30 to ~1.3x10^32 ergs, and found no corresponding response in the J, H, or Ks bandpasses at the precision of our data. For active dM3e stars, we find that a ~1.3x10^32 erg U-band flare (delta Umax ~1.5 mag) will induce, Accepted in Astronomical Journal, 17 pages, 6 figures
- Published
- 2011
46. Interstellar Sonic and Alfv\'enic Mach Numbers and the Tsallis Distribution
- Author
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A. Lazarian, Benjamin M. Tofflemire, and Blakesley Burkhart
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Turbulence ,Tsallis statistics ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Computational physics ,Physics::Fluid Dynamics ,symbols.namesake ,Amplitude ,Mach number ,Space and Planetary Science ,Physics::Plasma Physics ,0103 physical sciences ,Physics::Space Physics ,Compressibility ,symbols ,Probability distribution ,Tsallis distribution ,Magnetohydrodynamics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences - Abstract
In an effort to characterize the Mach numbers of ISM magnetohydrodynamic (MHD) turbulence, we study the probability distribution functions (PDFs) of patial increments of density, velocity, and magnetic field for fourteen ideal isothermal MHD simulations at resolution 512^3. In particular, we fit the PDFs using the Tsallis function and study the dependency of fit parameters on the compressibility and magnetization of the gas. We find that the Tsallis function fits PDFs of MHD turbulence well, with fit parameters showing sensitivities to the sonic and Alfven Mach numbers. For 3D density, column density, and position-position-velocity (PPV) data we find that the amplitude and width of the PDFs shows a dependency on the sonic Mach number. We also find the width of the PDF is sensitive to global Alfvenic Mach number especially in cases where the sonic number is high. These dependencies are also found for mock observational cases, where cloud-like boundary conditions, smoothing, and noise are introduced. The ability of Tsallis statistics to characterize sonic and Alfvenic Mach numbers of simulated ISM turbulence point to it being a useful tool in the analysis of the observed ISM, especially when used simultaneously with other statistical techniques., Comment: 20 pages, 16 figures, ApJ submitted
- Published
- 2011
47. Probing the Flare Atmospheres of M dwarfs Using Infrared Emission Lines
- Author
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Sarah J. Schmidt, Eric J. Hilton, Benjamin M. Tofflemire, Adam F. Kowalski, John P. Wisniewski, and Suzanne L. Hawley
- Subjects
Physics ,Infrared ,Infrared spectroscopy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Spectral line ,law.invention ,Photometry (optics) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,law ,Emission spectrum ,Spectroscopy ,Chromosphere ,Solar and Stellar Astrophysics (astro-ph.SR) ,Flare - Abstract
We present the results of a campaign to monitor active M dwarfs using infrared spectroscopy, supplemented with optical photometry and spectroscopy. We detected 16 flares during nearly 50 hours of observations on EV Lac, AD Leo, YZ CMi, and VB8. The three most energetic flares also showed infrared emission, including the first reported detections of P\beta, P\gamma, He I 10830\AA and Br\gamma during an M dwarf flare. The strongest flare (\Delta u = 4.02 on EV Lac) showed emission from H\gamma, H\delta, He I 4471\AA, and Ca II K in the UV/blue and P\beta, P\gamma, P\delta, Br\gamma, and He I 10830\AA in the infrared. The weaker flares (\Delta u = 1.68 on EV Lac and \Delta U = 1.38 on YZ CMi) were only observed with photometry and infrared spectroscopy; both showed emission from P\beta, P\gamma, and He I 10830\AA. The strongest infrared emission line, P\beta, occurred in the active mid-M dwarfs with a duty cycle of ~3-4%. To examine the most energetic flare, we used the static NLTE radiative transfer code RH to produce model spectra based on a suite of one-dimensional model atmospheres. Using a hotter chromosphere than previous one-dimensional atmospheric models, we obtain line ratios that match most of the observed emission lines., Comment: 12 pages, 9 figures, Accepted for publication in the Astrophysical Journal
- Published
- 2011
- Full Text
- View/download PDF
48. Near-infrared Multi-band Photometry of the Substellar Companion GJ 758 B
- Author
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Amaya Moro-Martin, Michihiro Takami, Thomas Henning, Benjamin M. Tofflemire, Michael W. McElwain, Naruhisa Takato, Lyu Abe, Masayuki Kuzuhara, Yutaka Hayano, Christian Thalmann, Miwa Goto, Gillian R. Knapp, Markus Janson, Eugene Serabyn, Wolfgang Brandner, Taro Matsuo, Tomonori Usuda, Adam Burrows, Saeko S. Hayashi, Jun-Ichi Morino, Hideki Takami, Hiroshi Suto, Sebastian Egner, Nobuhiko Kusakabe, Shoken Miyama, Tae-Soo Pyo, Olivier Guyon, Jun Hashimoto, Justin Crepp, Carol A. Grady, Satoshi Mayama, Masanori Iye, Taras Golota, Hiroshi Terada, John P. Wisniewski, Makoto Watanabe, Joseph C. Carson, Ryuji Suzuki, Tetsuro Nishimura, Miki Ishii, D. Tomono, Markus Feldt, Ryo Kandori, Klaus W. Hodapp, Edwin L. Turner, Motohide Tamura, Toru Yamada, Masahiko Hayashi, Tomoyuki Kudo, Laboratoire Hippolyte Fizeau (FIZEAU), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Infrared ,Near-infrared spectroscopy ,Brown dwarf ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Planetary system ,01 natural sciences ,Spectral line ,Photometry (optics) ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,0103 physical sciences ,Spectral energy distribution ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
GJ 758 B is a cold (~600K) companion to a Sun-like star at 29 AU projected separation, which was recently detected with high-contrast imaging. Here we present photometry of the companion in seven photometric bands from Subaru/HiCIAO, Gemini/NIRI and Keck/NIRC2, providing a rich sampling of the spectral energy distribution in the 1-5 micron wavelength range. A clear detection at 1.58 micron combined with an upper limit at 1.69 micron shows methane absorption in the atmosphere of the companion. The mass of the companion remains uncertain, but an updated age estimate indicates that the most likely mass range is ~30-40 Mjup. In addition, we present an updated astrometric analysis that imposes tighter constraints on GJ 758 B's orbit and identifies the proposed second candidate companion, "GJ 758 C", as a background star., Comment: 10 pages, 4 figures, accepted for publication in ApJ Letters. New version: Corrected a few numbers in the astrometry section (which were already correct in the print version, but were based on an outdated simulation in the astro-ph version)
- Published
- 2011
49. A MULTI-SURVEY APPROACH TO WHITE DWARF DISCOVERY
- Author
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Conor Sayres, James R. A. Davenport, Patrick Dufour, Pierre Bergeron, Benjamin M. Tofflemire, Y. AlSayyad, and John P. Subasavage
- Subjects
Physics ,Proper motion ,010308 nuclear & particles physics ,media_common.quotation_subject ,FOS: Physical sciences ,White dwarf ,Astronomy and Astrophysics ,Atmospheric model ,Astrophysics ,01 natural sciences ,Photometry (optics) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Sky ,0103 physical sciences ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,media_common - Abstract
By selecting astrometric and photometric data from the Sloan Digital Sky Survey (SDSS), the L{��}pine & Shara Proper Motion North Catalog (LSPM-North), the Two Micron All Sky Survey (2MASS), and the USNO-B1.0 catalog, we use a succession of methods to isolate white dwarf candidates for follow-up spectroscopy. Our methods include: reduced proper motion diagram cuts, color cuts, and atmospheric model adherence. We present spectroscopy of 26 white dwarfs obtained from the CTIO 4m and APO 3.5m telescopes. Additionally, we confirm 28 white dwarfs with spectra available in the SDSS DR7 database but unpublished elsewhere, presenting a total of 54 WDs. We label one of these as a recovered WD while the remaining 53 are new discoveries. We determine physical parameters and estimate distances based on atmospheric model analyses. Three new white dwarfs are modeled to lie within 25 pc. Two additional white dwarfs are confirmed to be metal-polluted (DAZ). Follow-up time series photometry confirms another object to be a pulsating ZZ Ceti white dwarf., 9 figures, 3 Tables; http://stacks.iop.org/1538-3881/143/103
- Published
- 2012
50. Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary.
- Author
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Benjamin M. Tofflemire, Robert D. Mathieu, and Christopher M. Johns-Krull
- Published
- 2019
- Full Text
- View/download PDF
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