617 results on '"Sara, Seager"'
Search Results
602. TESS Delivers Its First Earth-sized Planet and a Warm Sub-Neptune.
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Diana Dragomir, Johanna Teske, Maximilian N. Günther, Damien Ségransan, Jennifer A. Burt, Chelsea X. Huang, Andrew Vanderburg, Elisabeth Matthews, Xavier Dumusque, Keivan G. Stassun, Joshua Pepper, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Thomas Beatty, François Bouchy, and Timothy M. Brown
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- 2019
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603. TESS Discovery of an Ultra-short-period Planet around the Nearby M Dwarf LHS 3844.
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Roland Vanderspek, Chelsea X. Huang, Andrew Vanderburg, George R. Ricker, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Jennifer Burt, Jason Dittmann, Elisabeth Newton, Samuel N. Quinn, Avi Shporer, David Charbonneau, Jonathan Irwin, Kristo Ment, Jennifer G. Winters, Karen A. Collins, Phil Evans, and Tianjun Gan
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- 2019
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604. TESS Discovery of a Transiting Super-Earth in the pi Mensae System.
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Chelsea X. Huang, Jennifer Burt, Andrew Vanderburg, Maximilian N. Günther, Avi Shporer, Jason A. Dittmann, Joshua N. Winn, Rob Wittenmyer, Lizhou Sha, Stephen R. Kane, George R. Ricker, Roland K. Vanderspek, David W. Latham, Sara Seager, Jon M. Jenkins, Douglas A. Caldwell, Karen A. Collins, Natalia Guerrero, Jeffrey C. Smith, and Samuel N. Quinn
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- 2018
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605. TOI-3362b: A Proto Hot Jupiter Undergoing High-eccentricity Tidal Migration
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Songhu Wang, Joseph E. Rodriguez, Olga Suarez, Kevin I. Collins, Hui-Gen Liu, Brendan P. Bowler, Amaury H. M. J. Triaud, Djamel Mékarnia, Jessie L. Christiansen, Rebekah I. Dawson, Peter Plavchan, George Zhou, Jonathan Horner, Jonathon M. Jackson, Jon M. Jenkins, David W. Latham, Eric L. N. Jensen, Jiayin Dong, Joshua N. Winn, Georgina Dransfield, Duncan J. Wright, Alexis Heitzmann, Nicolas Crouzet, Chelsea X. Huang, Martin Paegert, Roland Vanderspek, George R. Ricker, Khalid Barkaoui, Stephen R. Kane, Matthew W. Mengel, Jason D. Eastman, Sara Seager, Chris Stockdale, Samuel N. Quinn, Brett C. Addison, Jack Okumura, Robert A. Wittenmyer, John F. Kielkopf, Avi Shporer, Thomas G. Beatty, Karen A. Collins, and Lyu Abe
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Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,05 social sciences ,FOS: Physical sciences ,050301 education ,Astronomy ,Astronomy and Astrophysics ,Tidal heating ,Orbital eccentricity ,Orbital period ,01 natural sciences ,Radial velocity ,Orbit ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,Astrophysics::Earth and Planetary Astrophysics ,Tidal circularization ,010303 astronomy & astrophysics ,0503 education ,Astrophysics - Earth and Planetary Astrophysics - Abstract
High-eccentricity tidal migration is a possible way for giant planets to be emplaced in short-period orbits. If it commonly operates, one would expect to catch proto-Hot Jupiters on highly elliptical orbits that are undergoing high-eccentricity tidal migration. As of yet, few such systems have been discovered. Here, we introduce TOI-3362b (TIC-464300749b), an 18.1-day, 5 $M_{\rm Jup}$ planet orbiting a main-sequence F-type star that is likely undergoing high-eccentricity tidal migration. The orbital eccentricity is 0.815$^{+0.023}_{-0.032}$. With a semi-major axis of 0.153$^{+0.002}_{-0.003}$ au, the planet's orbit is expected to shrink to a final orbital radius of 0.051$^{+0.008}_{-0.006}$ au after complete tidal circularization. Several mechanisms could explain the extreme value of the planet's eccentricity, such as planet-planet scattering and secular interactions. Such hypotheses can be tested with follow-up observations of the system, e.g., measuring the stellar obliquity and searching for companions in the system with precise, long-term radial velocity observations. The variation in the planet's equilibrium temperature as it orbits the host star and the tidal heating at periapse make this planet an intriguing target for atmospheric modeling and observation. Because the planet's orbital period of 18.1 days is near the limit of TESS's period sensitivity, even a few such discoveries suggest that proto-Hot Jupiters may be quite common., Comment: 14 pages, 4 figures, 2 tables. submitted to ApJL, revised in response to referee report
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606. TOI-824 b: A New Planet on the Lower Edge of the Hot Neptune Desert
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Xavier Dumusque, Jon M. Jenkins, Jason D. Eastman, Ravit Helled, Samuel N. Quinn, M. Soto, Elisabeth Matthews, Roland Vanderspek, J. Haldemann, Jennifer Burt, Maximilian N. Günther, Sara Seager, Stephen A. Shectman, Karen A. Collins, Thiam-Guan Tan, George Zhou, Fabo Feng, Tansu Daylan, R. Paul Butler, George R. Ricker, Andrew Vanderburg, Sharon X. Wang, Keivan G. Stassun, Julia V. Seidel, Louise D. Nielsen, Joseph E. Rodriguez, Laura Kreidberg, Erin Flowers, Thomas Barclay, Jeffrey D. Crane, Jeffrey C. Smith, Gilbert A. Esquerdo, Benjamin T. Montet, Chelsea X. Huang, Eric E. Mamajek, Eric L. N. Jensen, Peter Tenenbaum, John F. Kielkopf, Tianjun Gan, Samuel Halverson, François Bouchy, Jack J. Lissauer, Damien Segransen, David W. Latham, Adina D. Feinstein, Caroline Dorn, Joshua Pepper, Johanna Teske, Eric D. Lopez, Joshua N. Winn, Dennis M. Conti, Kevin I. Collins, Joseph D. Twicken, J. F. Otegi, Scott Cartwright, Yuri Beletski, and William Fong
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Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Star (game theory) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Orbital period ,01 natural sciences ,Exoplanet ,Radial velocity ,Atmosphere ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Planet ,Neptune ,0103 physical sciences ,Hot Neptune ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We report the detection of a transiting hot Neptune exoplanet orbiting TOI-824 (SCR J1448-5735), a nearby (d = 64 pc) K4V star, using data from the \textit{Transiting Exoplanet Survey Satellite} (TESS). The newly discovered planet has a radius, $R_{\rm{p}}$ = 2.93 $\pm$ 0.20 R$_{\oplus}$, and an orbital period of 1.393 days. Radial velocity measurements using the Planet Finder Spectrograph (PFS) and the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph confirm the existence of the planet and we estimate its mass to be $M_{\rm{p}}$ = 18.47 $\pm$ 1.84 M$_{\oplus}$. The planet's mean density is $\rho_{\rm{p}}$ = 4.03$^{+0.98}_{-0.78}$ g cm$^{-3}$ making it more than twice as dense as Neptune. TOI-824 b's high equilibrium temperature makes the planet likely to have a cloud free atmosphere, and thus an excellent candidate for follow up atmospheric studies. The detectability of TOI-824 b's atmosphere from both ground and space is promising and could lead to the detailed characterization of the most irradiated, small planet at the edge of the hot Neptune desert that has retained its atmosphere to date., Comment: 22 pages, 10 figures. Accepted for publication in the Astronomical Journal
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607. TESS and HARPS reveal two sub-Neptunes around TOI 1062
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J. N. Winn, Roland Vanderspek, A. Hadjigeorghiou, Sergio Hoyer, J. F. Otegi, Caroline Dorn, Brian McLean, Vardan Adibekyan, J.-B. Delisle, Matteo Brogi, Angelica Psaridi, George R. Ricker, David R. Ciardi, Nathan Hara, Karen A. Collins, D. A. Caldwell, Stéphane Udry, R. Schwarz, Keivan G. Stassun, Chris Henze, Daniel Bayliss, Elisa Delgado-Mena, Andrew Vanderburg, Louise D. Nielsen, David J. Armstrong, Sara Seager, S. C. C. Barros, Nuno C. Santos, David Barrado, M. Fridlund, Siddharth Gandhi, Ravit Helled, M. Stalport, P. Figueira, Xavier Dumusque, G. Wang, H. P. Osborn, Robert F. Goeke, Jason D. Eastman, Jon M. Jenkins, François Bouchy, S. G. Sousa, P. A. Strøm, Natalia Guerrero, Dennis M. Conti, D. W. Latham, D. J. A. Brown, A. Osborn, J. Lillo-Box, P. T. Boyd, S. Hojjatpanah, Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
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Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Orbital elements ,010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Radius ,Planets and satellites: detection ,Astrophysics - Earth and planetary astrophysics ,Orbital period ,01 natural sciences ,Exoplanet ,Planets and satellites: composition ,Radial velocity ,Stars ,Mean motion ,Planets and satellites: general ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,Planet ,0103 physical sciences ,010303 astronomy & astrophysics ,QB ,0105 earth and related environmental sciences - Abstract
The Transiting Exoplanet Survey Satellite (\textit{TESS}) mission was designed to perform an all-sky search of planets around bright and nearby stars. Here we report the discovery of two sub-Neptunes orbiting around the TOI 1062 (TIC 299799658), a V=10.25 G9V star observed in the TESS Sectors 1, 13, 27 & 28. We use precise radial velocity observations from HARPS to confirm and characterize these two planets. TOI 1062b has a radius of 2.265^{+0.095}_{-0.091} Re, a mass of 11.8 +\- 1.4 Me, and an orbital period of 4.115050 +/- 0.000007 days. The second planet is not transiting, has a minimum mass of 7.4 +/- 1.6 Me and is near the 2:1 mean motion resonance with the innermost planet with an orbital period of 8.13^{+0.02}_{-0.01} days. We performed a dynamical analysis to explore the proximity of the system to this resonance, and to attempt at further constraining the orbital parameters. The transiting planet has a mean density of 5.58^{+1.00}_{-0.89} g cm^-3 and an analysis of its internal structure reveals that it is expected to have a small volatile envelope accounting for 0.35% of the mass at maximum. The star's brightness and the proximity of the inner planet to the "radius gap" make it an interesting candidate for transmission spectroscopy, which could further constrain the composition and internal structure of TOI 1062b., 14 pages, 11 figures
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608. The Multiplanet System TOI-421
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Savita Mathur, Grzegorz Nowak, M. Hjorth, Simon Albrecht, Matias Diaz, Thomas Henning, François Bouchy, Diana Dragomir, Keivan G. Stassun, Michael B. Lund, Petr Kabath, Francesco Borsa, Serena Benatti, Davide Gandolfi, Andrés Jordán, Sharon X. Wang, R. Paul Butler, Andrew W. Howard, Anders Erikson, Néstor Espinoza, Eike W. Guenther, Jack Lubin, Aurélien Wyttenbach, Fei Dai, Jeffrey C. Smith, Ângela R. G. Santos, Nolan Grieves, Stephen R. Kane, David Nespral, L. M. Serrano, Ilaria Carleo, Massimiliano Esposito, Diego Hidalgo, Rafael Luque, Lauren M. Weiss, Alexis M. S. Smith, Paula Sarkis, Matias I. Jones, Erica J. Gonzales, George R. Ricker, Emil Knudstrup, Iskra Georgieva, Sara Seager, Luca Fossati, Florian Rodler, Stephen A. Shectman, Erik A. Petigura, Patricia T. Boyd, K. W. F. Lam, Teruyuki Hirano, Coel Hellier, Fabo Feng, Javier Alarcon, Rafael Brahm, Jon M. Jenkins, Joshua E. Schlieder, Natalia Guerrero, Judith Korth, Norio Narita, Carolina Villarreal D'Angelo, Joshua N. Winn, Courtney D. Dressing, Benjamin J. Fulton, David W. Latham, Enric Palle, Damien Ségransan, Daniel Huber, John H. Livingston, Malcolm Fridlund, Ismael Mireles, William D. Cochran, Erin Flowers, Corey Beard, Louise D. Nielsen, Paul Robertson, Karen A. Collins, Roland Vanderspek, Heike Rauer, Prajwal Niraula, Michael Fausnaugh, Rafael A. García, Carina M. Persson, L. González-Cuesta, Arpita Roy, Paul Mollière, Martin Pätzold, Jeffrey D. Crane, David R. Ciardi, Michael Endl, Szilard Csizmadia, Seth Redfield, Natalie M. Batalha, Mark E. Rose, Hans J. Deeg, Antonija Oklopčić, Howard Isaacson, Vincent Van Eylen, Oscar Barragán, Artie P. Hatzes, Marek Skarka, Daria Kubyshkina, Jorge Prieto-Arranz, Sascha Grziwa, Kevin I. Collins, Ian J. M. Crossfield, Joseph D. Twicken, Philipp Eigmüller, Jennifer Burt, Johanna Teske, Juan Cabrera, Lorenzo Spina, Ashley Chontos, and Aline A. Vidotto
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Physics ,010504 meteorology & atmospheric sciences ,Astronomy and Astrophysics ,Astrophysics ,Radius ,01 natural sciences ,Exoplanet ,Radial velocity ,Photometry (astronomy) ,13. Climate action ,Space and Planetary Science ,Neptune ,Planet ,0103 physical sciences ,Transit (astronomy) ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Visual binary - Abstract
We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations-comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echelle Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution echelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements-and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P-b = 5.19672 +/- 0.00049 days, a mass of M-b = 7.17 +/- 0.66 M-circle plus, and a radius of R-b = R-circle plus, whereas the outer warm Neptune, TOI-421 c, has a period of P-c = 16.06819 +/- 0.00035 days, a mass of M-c = 16.42(-1.04)(+1.06)M(circle plus), a radius of R-c = 5.09(-0.15)(+0.16)R(circle plus), and a density of rho(c) = 0.685(-0.072)(+0.080) cm(-3). With its characteristics, the outer planet (rho(c) = 0.685(-0.0072)(+0.080) cm(-3)) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Ly alpha transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed.
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609. A Transiting Warm Giant Planet around the Young Active Star TOI-201
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Rafael Brahm, Martin Schlecker, Thomas Henning, Alexis M. S. Smith, Louise D. Nielsen, François Bouchy, Andrés Jordán, Bill Wohler, N. Unger, George R. Ricker, C. G. Tinney, Joshua N. Winn, Stephen R. Kane, Trifon Trifonov, Matthew W. Mengel, Richard G. West, Matias I. Jones, John F. Kielkopf, Tansu Daylan, Rosanna H. Tilbrook, Stéphane Udry, Peter Plavchan, Brian McLean, Nolan Grieves, Robert A. Wittenmyer, Jonathan Horner, Avraham Binnenfeld, Shay Zucker, Sara Seager, Brett C. Addison, Jack Okumura, David W. Latham, Daniel Thorngren, Duncan J. Wright, Chelsea X. Huang, Joseph D. Twicken, Sahar Shahaf, Joshua T. Briegal, Diana Kossakowski, Brendan P. Bowler, Pascal Torres, Karen Collins, Jon M. Jenkins, Paula Sarkis, Avi Shporer, Néstor Espinoza, Melissa J. Hobson, Edward M. Bryant, and Felipe Rojas
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Extrasolare Planeten und Atmosphären ,Radial velocity ,010504 meteorology & atmospheric sciences ,Exoplanet astronomy ,FOS: Physical sciences ,Orbital eccentricity ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Planet ,0103 physical sciences ,Exoplanet detection methods ,Astrophysics::Solar and Stellar Astrophysics ,Transit (astronomy) ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Giant planet ,Astronomy ,Astronomy and Astrophysics ,Radius ,Exoplanet ,Photometry (astronomy) ,13. Climate action ,Space and Planetary Science ,High Energy Physics::Experiment ,Astrophysics::Earth and Planetary Astrophysics ,Transit photometry ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present the confirmation of the eccentric warm giant planet TOI-201 b, first identified as a candidate in \textit{TESS} photometry (Sectors 1-8, 10-13, and 27-28) and confirmed using ground-based photometry from NGTS and radial velocities from FEROS, HARPS, CORALIE, and \textsc{Minerva}-Australis. TOI-201 b orbits a young ($\mathrm{0.87^{+0.46}_{-0.49} \, Gyr}$) and bright(V=9.07 mag) F-type star with a $\mathrm{52.9781 \, d}$ period. The planet has a mass of $\mathrm{0.42^{+0.05}_{-0.03}\, M_J}$, a radius of $\mathrm{1.008^{+0.012}_{-0.015}\, R_J}$, and an orbital eccentricity of $0.28^{+0.06}_{-0.09}$; it appears to still be undergoing fairly rapid cooling, as expected given the youth of the host star. The star also shows long-term variability in both the radial velocities and several activity indicators, which we attribute to stellar activity. The discovery and characterization of warm giant planets such as TOI-201 b is important for constraining formation and evolution theories for giant planets., 21 pages, 11 figures, accepted to AJ
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610. WASP-4b Arrived Early for the TESS Mission
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Sara Seager, Jon M. Jenkins, J. D. Twicken, Michael Fausnaugh, Bill Wohler, Claire Baxter, N. Guerrero, Michelle L. Hill, Tansu Daylan, Stephen R. Kane, L. G. Bouma, Keivan G. Stassun, David W. Latham, Knicole D. Colón, Fei Dai, Zachory K. Berta-Thompson, Jean-Michel Desert, Waqas Bhatti, Joshua N. Winn, Joseph E. Rodriguez, J. Villasenor, Ana Glidden, Roland Vanderspek, George R. Ricker, and Low Energy Astrophysics (API, FNWI)
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Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,010504 meteorology & atmospheric sciences ,Apsidal precession ,FOS: Physical sciences ,Astronomy ,Astronomy and Astrophysics ,Orbital decay ,Orbital period ,01 natural sciences ,Exoplanet ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,Satellite ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics - Earth and Planetary Astrophysics ,0105 earth and related environmental sciences - Abstract
The Transiting Exoplanet Survey Satellite (TESS) recently observed 18 transits of the hot Jupiter WASP-4b. The sequence of transits occurred 81.6 $\pm$ 11.7 seconds earlier than had been predicted, based on data stretching back to 2007. This is unlikely to be the result of a clock error, because TESS observations of other hot Jupiters (WASP-6b, 18b, and 46b) are compatible with a constant period, ruling out an 81.6-second offset at the 6.4$\sigma$ level. The 1.3-day orbital period of WASP-4b appears to be decreasing at a rate of $\dot{P} = -12.6 \pm 1.2$ milliseconds per year. The apparent period change might be caused by tidal orbital decay or apsidal precession, although both interpretations have shortcomings. The gravitational influence of a third body is another possibility, though at present there is minimal evidence for such a body. Further observations are needed to confirm and understand the timing variation., Comment: AJ accepted
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611. A Highly Eccentric Warm Jupiter Orbiting TIC 237913194
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Andrés Jordán, Rafael Brahm, Samuel N. Quinn, Sara Seager, Vincent Suc, Waqas Bhatti, Karan Molaverdikhani, Trifon Trifonov, Mark E. Rose, David J. Osip, Felipe Rojas, George R. Ricker, Néstor Espinoza, J. Villasenor, Paul Mollière, Michael Vezie, David R. Rodriguez, Ludmila Carone, Joseph E. Rodriguez, Avi Shporer, Thomas Henning, David W. Latham, Hubert Klahr, Roland Vanderspek, Joshua N. Winn, Melissa J. Hobson, Martin Schlecker, G. Á. Bakos, Paula Sarkis, Jon M. Jenkins, and Diana Kossakowski
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Physics ,Orbital elements ,Earth and Planetary Astrophysics (astro-ph.EP) ,010504 meteorology & atmospheric sciences ,Star (game theory) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Jupiter ,Radial velocity ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,Hot Jupiter ,Astrophysics::Solar and Stellar Astrophysics ,Absorption (logic) ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Energy (signal processing) ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Earth and Planetary Astrophysics ,0105 earth and related environmental sciences - Abstract
The orbital parameters of warm Jupiters serve as a record of their formation history, providing constraints on formation scenarios for giant planets on close and intermediate orbits. Here, we report the discovery of TIC 237913194b, detected in full frame images from Sectors 1 and 2 of TESS, ground-based photometry (CHAT, LCOGT), and FEROS radial velocity time series. We constrain its mass to $M_\mathrm{P} = 1.942_{-0.091}^{+0.091}\,{\rm M_{J}} $, and its radius to $R_\mathrm{P} = 1.117_{-0.047}^{+0.054}\,{\rm R_J}$, implying a bulk density similar to Neptune's. It orbits a G-type star (${\rm M}_{\star} = 1.026_{-0.055}^{+0.057}\,{\rm M}_{\odot}$, $V = 12.1$ mag) with a period of $15.17\,$d on one of the most eccentric orbits of all known warm giants ($e \approx 0.58$). This extreme dynamical state points to a past interaction with an additional, undetected massive companion. A tidal evolution analysis showed a large tidal dissipation timescale, suggesting that the planet is not a progenitor for a hot Jupiter caught during its high-eccentricity migration. TIC 237913194b further represents an attractive opportunity to study the energy deposition and redistribution in the atmosphere of a warm Jupiter with high eccentricity., Comment: 20 pages, 14 figures. Accepted for publication in AJ
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612. TESS Delivers Five New Hot Giant Planets Orbiting Bright Stars from the Full-frame Images
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Enric Palle, Ryan J. Oelkers, Thomas Henning, Sydney Vach, Paula Sarkis, Rudolf B. Kuhn, Julia V. Seidel, François Bouchy, Nicholas M. Law, Arjun B. Savel, Jessie L. Christiansen, Eric L. N. Jensen, David Baker, Thomas Barclay, Dax L. Feliz, Alan M. Levine, Scott Cartwright, Jessica Mink, Néstor Espinoza, Kevin Eastridge, George R. Ricker, Keivan G. Stassun, Katharine Hesse, Stephen R. Kane, Rachel A. Matson, Karen Collins, Brendan P. Bowler, Steve B. Howell, Nolan Grieves, Richard G. West, Erica J. Gonzales, Roland Vanderspek, Gavin Wang, Justin M. Wittrock, Massimiliano Esposito, Samuel N. Quinn, Daniel A. Yahalomi, Michael L. Calkins, Andrés Jordán, Shude Mao, B. Scott Gaudi, Lindsey Gordon, Peter Plavchan, Chloe Schnaible, Robert A. Wittenmyer, Eike W. Guenther, Joshua Pepper, William Fong, C. E. Brasseur, Jason D. Eastman, Ian J. M. Crossfield, Phillip A. Reed, Sam Christian, David J. James, Michael B. Lund, Andrew Vanderburg, Kim K. McLeod, C. G. Tinney, Ilaria Carleo, Elisabeth Matthews, Patrick Newman, Joseph E. Rodriguez, Jonathan Horner, Courtney D. Dressing, Avi Shporer, Holden Gill, Robert J. Siverd, Perry Berlind, John F. Kielkopf, Tianjun Gan, Sudhish Chimaladinne, Michael Bowen, Caitlin Stibbards, Don J. Radford, Coel Hellier, Tanner O'Dwyer, Thomas G. Beatty, Steven Giacalone, Daniel J. Stevens, Douglas A. Caldwell, Thiam-Guan Tan, George Zhou, Cesar Briceno, Kevin I. Collins, A. Granados, Hui Zhang, Duncan J. Wright, Louise D. Nielsen, David R. Anderson, Chelsea X. Huang, Brett Skinner, Richard P. Schwarz, Elisa V. Quintana, Joshua E. Schlieder, Natalia Guerrero, Joshua N. Winn, Christopher E. Henze, Andrew W. Mann, Melissa J. Hobson, Tyler Fenske, Guillaume Chaverot, Priyanka Chaturvedi, Matthew W. Mengel, Allyson Bieryla, Natasha Latouf, David W. Latham, M. Stalport, Ramotholo Sefako, Kingsley Kim, David R. Ciardi, Carl Ziegler, Sara Seager, Brett C. Addison, Gilbert A. Esquerdo, Jack Okumura, Mary Jimenez, Rafael Brahm, and Jon M. Jenkins
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010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Orbital eccentricity ,Astrophysics ,Q1 ,01 natural sciences ,7. Clean energy ,Jovian ,Jupiter ,Planet ,QB460 ,0103 physical sciences ,Hot Jupiter ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,QB600 ,QB ,0105 earth and related environmental sciences ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Astronomy and Astrophysics ,Exoplanet ,Radial velocity ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,QB799 ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present the discovery and characterization of five hot and warm Jupiters -- TOI-628 b (TIC 281408474; HD 288842), TOI-640 b (TIC 147977348), TOI-1333 b (TIC 395171208, BD+47 3521A), TOI-1478 b (TIC 409794137), and TOI-1601 b (TIC 139375960) -- based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The five planets were identified from the full frame images and were confirmed through a series of photometric and spectroscopic follow-up observations by the $TESS$ Follow-up Observing Program (TFOP) Working Group. The planets are all Jovian size (R$_{\rm P}$ = 1.01-1.77 R$_{\rm J}$) and have masses that range from 0.85 to 6.33 M$_{\rm J}$. The host stars of these systems have F and G spectral types (5595 $\le$ T$_{\rm eff}$ $\le$ 6460 K) and are all relatively bright (9 $ 1.7R$_{\rm J}$, possibly a result of its host star's evolution) and resides on an orbit with a period longer than 5 days. TOI-628 b is the most massive hot Jupiter discovered to date by $TESS$ with a measured mass of $6.31^{+0.28}_{-0.30}$ M$_{\rm J}$ and a statistically significant, non-zero orbital eccentricity of e = $0.074^{+0.021}_{-0.022}$. This planet would not have had enough time to circularize through tidal forces from our analysis, suggesting that it might be remnant eccentricity from its migration. The longest period planet in this sample, TOI-1478 b (P = 10.18 days), is a warm Jupiter in a circular orbit around a near-Solar analogue. NASA's $TESS$ mission is continuing to increase the sample of well-characterized hot and warm Jupiters, complementing its primary mission goals., Comment: 25 Pages, 7 Figures, 5 Tables, Accepted to The Astronomical Journal
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613. EMERGING POSSIBILITIES AND INSUPERABLE LIMITATIONS OF EXOGEOPHYSICS: THE EXAMPLE OF PLATE TECTONICS.
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Vlada Stamenković and Sara Seager
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GEOPHYSICS , *PLATE tectonics , *EXTRASOLAR planets , *PLANETARY mass , *EARTH (Planet) - Abstract
To understand the evolution and the habitability of any rocky exoplanet demands detailed knowledge about its geophysical state and history—such as predicting the tectonic mode of a planet. Yet no astronomical observation can directly confirm or rule out the occurrence of plate tectonics on a given exoplanet. Moreover, the field of plate tectonics is still young—questioning whether we should study plate tectonics on exoplanets at this point in time. In this work, we determine the limitations and the emerging possibilities of exogeophysics, the science of connecting geophysics to exoplanets, on the example of plate tectonics. Assuming current uncertainties in model and planet parameters, we develop a qualitatively probabilistic and conservative framework to estimate on what kind of planets and where in the Galaxy plate tectonics might occur. This we achieve by modeling how plate yielding, the most critical condition needed for plate mobility and subduction, is affected by directly observable (planet mass, size) or indirectly, to some degree, assessable planet properties (structure and composition). Our framework not only highlights the importance of a planet’s chemistry for the existence of plate tectonics and the path toward practical exogeophysics but also demonstrates how exoplanet science can actually help to better understand geophysics and the fundamentals of plate tectonics on Earth itself. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
614. HELIUM ATMOSPHERES ON WARM NEPTUNE- AND SUB-NEPTUNE-SIZED EXOPLANETS AND APPLICATIONS TO GJ 436b.
- Author
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Renyu Hu, Sara Seager, and Yuk L. Yung
- Subjects
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SATELLITES of Neptune , *NATURAL satellites , *EXTRASOLAR planets , *STARS with planets , *PLANETARY research - Abstract
Warm Neptune- and sub-Neptune-sized exoplanets in orbits smaller than Mercury’s are thought to have experienced extensive atmospheric evolution. Here we propose that a potential outcome of this atmospheric evolution is the formation of helium-dominated atmospheres. The hydrodynamic escape rates of Neptune- and sub-Neptune-sized exoplanets are comparable to the diffusion-limited escape rate of hydrogen, and therefore the escape is heavily affected by diffusive separation between hydrogen and helium. A helium atmosphere can thus be formed—from a primordial hydrogen–helium atmosphere—via atmospheric hydrodynamic escape from the planet. The helium atmosphere has very different abundances of major carbon and oxygen species from those of a hydrogen atmosphere, leading to distinctive transmission and thermal emission spectral features. In particular, the hypothesis of a helium-dominated atmosphere can explain the thermal emission spectrum of GJ 436b, a warm Neptune-sized exoplanet, while also being consistent with the transmission spectrum. This model atmosphere contains trace amounts of hydrogen, carbon, and oxygen, with the predominance of CO over CH4 as the main form of carbon. With our atmospheric evolution model, we find that if the mass of the initial atmosphere envelope is 10−3 planetary mass, hydrodynamic escape can reduce the hydrogen abundance in the atmosphere by several orders of magnitude in ∼10 billion years. Observations of exoplanet transits may thus detect signatures of helium atmospheres and probe the evolutionary history of small exoplanets. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
615. LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS.
- Author
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Jean-Michel Désert, David Charbonneau, Guillermo Torres, François Fressin, Sarah Ballard, Stephen T. Bryson, Heather A. Knutson, Natalie M. Batalha, William J. Borucki, Timothy M. Brown, Drake Deming, Eric B. Ford, Jonathan J. Fortney, Ronald L. Gilliland, David W. Latham, and Sara Seager
- Subjects
ECLIPSES ,SPHERICAL astronomy ,ASTRONOMICAL transits ,CELESTIAL mechanics ,NATURAL satellites - Abstract
NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the SpitzerSpace Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated by the Kepler observations, provides an independent indication that Kepler’s FPR is low. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
616. A SEMI-ANALYTICAL MODEL OF VISIBLE-WAVELENGTH PHASE CURVES OF EXOPLANETS AND APPLICATIONS TO KEPLER- 7 B AND KEPLER- 10 B.
- Author
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Renyu Hu, Brice-Olivier Demory, Sara Seager, Nikole Lewis, and Adam P. Showman
- Subjects
CURVES ,GEOMETRY ,EXTRASOLAR planets ,PLANETS ,KEPLER'S laws - Abstract
Kepler has detected numerous exoplanet transits by measuring stellar light in a single visible-wavelength band. In addition to detection, the precise photometry provides phase curves of exoplanets, which can be used to study the dynamic processes on these planets. However, the interpretation of these observations can be complicated by the fact that visible-wavelength phase curves can represent both thermal emission and scattering from the planets. Here we present a semi-analytical model framework that can be applied to study Kepler and future visible-wavelength phase curve observations of exoplanets. The model efficiently computes reflection and thermal emission components for both rocky and gaseous planets, considering both homogeneous and inhomogeneous surfaces or atmospheres. We analyze the phase curves of the gaseous planet Kepler- 7 b and the rocky planet Kepler- 10 b using the model. In general, we find that a hot exoplanet’s visible-wavelength phase curve having a significant phase offset can usually be explained by two classes of solutions: one class requires a thermal hot spot shifted to one side of the substellar point, and the other class requires reflective clouds concentrated on the same side of the substellar point. Particularly for Kepler- 7 b, reflective clouds located on the west side of the substellar point can best explain its phase curve. The reflectivity of the clear part of the atmosphere should be less than 7% and that of the cloudy part should be greater than 80%, and the cloud boundary should be located at 11° ± 3° to the west of the substellar point. We suggest single-band photometry surveys could yield valuable information on exoplanet atmospheres and surfaces. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
617. Quotation Of The Day.
- Author
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SARA SEAGER
- Subjects
- *
PLANETS - Abstract
This planet broke the rule. SARA SEAGER, a planetary expert at the Massachusetts Institute of Technology, on the discovery of a planet orbiting two stars. [A11] [ABSTRACT FROM AUTHOR]
- Published
- 2011
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