Browsing by Author "Seager, S."

Now showing 1 - 13 of 13
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    A Highly Eccentric Warm Jupiter Orbiting TIC 237913194
    (2020) Schlecker, M.; Kossakowski, D.; Brahm, R.; Espinoza, N.; Henning, T.; Carone, L.; Molaverdikhani, K.; Trifonov, T.; Molliere, P.; Rojas Henriquez, Felipe Ignacio; Hobson, M. J.; Jordán Colzani, Andrés Cristóbal; Klahr, H.; Sarkis, P.; Bakos, G. A.; Bhatti, W.; Osip, D.; Suc, V.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Vezie, M.; Villasenor, J. N.; Rose, M. E.; Rodríguez, D. R.; Rodríguez, J. E.; Quinn, S. N.; Shporer, A.
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    A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS
    (2020) Astudillo Defru, N.; Cloutier, R.; Wang, S. X.; Teske, J.; Brahm Scott, Rafael; Hellier, C.; Ricker, G.; Vanderspek, R.; Latham, D.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Collins, K. A.; Stassun, K. G.; Ziegler, C.; Almenara, J. M.; Anderson, D. R.; Artigau, E.; Bonfils, X.; Bouchy, F.; Briceño, C.; Butler, R. P.; Charbonneau, D.; Conti, D. M.; Crane, J.; Crossfield, I. J. M.; Davies, M.; Delfosse, X.; Díaz, R. F.; Doyon, R.; Dragomir, D.; Eastman, J. D.; Espinoza, N.; Essack, Z.; Feng, F.; Figueira, P.; Forveille, T.; Gan, T.; Glidden, A.; Guerrero, N.; Hart, R.; Henning, T.; Horch, E. P.; Isopi, G.; Jenkins, J. S.; Jordán, A.; Kielkopf, J. F.; Law, N.; Lovis, C.; Mallia, F.
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    A Transiting Warm Giant Planet around the Young Active Star TOI-201
    (2021) Hobson, Melissa J.; Brahm, Rafael; Jordan, Andres; Espinoza, Nestor; Kossakowski, Diana; Henning, Thomas; Rojas, Felipe; Schlecker, Martin; Sarkis, Paula; Trifonov, Trifon; Thorngren, Daniel; Binnenfeld, Avraham; Shahaf, Sahar; Zucker, Shay; Ricker, George R.; Latham, David W.; Seager, S.; Winn, Joshua N.; Jenkins, Jon M.; Addison, Brett; Bouchy, Francois; Bowler, Brendan P.; Briegal, Joshua T.; Bryant, Edward M.; Collins, Karen A.; Daylan, Tansu; Grieves, Nolan; Horner, Jonathan; Huang, Chelsea; Kane, Stephen R.; Kielkopf, John; McLean, Brian; Mengel, Matthew W.; Nielsen, Louise D.; Okumura, Jack; Jones, Matias; Plavchan, Peter; Shporer, Avi; Smith, Alexis M. S.; Tilbrook, Rosanna; Tinney, C. G.; Twicken, Joseph D.; Udry, Stephane; Unger, Nicolas; West, Richard; Wittenmyer, Robert A.; Wohler, Bill; Torres, Pascal; Wright, Duncan J.
    We present the confirmation of the eccentric warm giant planet TOI-201 b, first identified as a candidate in Transiting Exoplanet Survey Satellite photometry (Sectors 1-8, 10-13, and 27-28) and confirmed using groundbased photometry from Next Generation Transit Survey and radial velocities from FEROS, HARPS, CORALIE, and MINERVA-Australis. TOI-201 b orbits a young (0.87(-0.49)(+0.46)) and bright (V = 9.07 mag) F-type star with a 52.9781 day period. The planet has a mass of 0.42(-0.03)(+0.05) M-J, a radius of 1.008(-0.015)(+0.012) R-J, and an orbital eccentricity of 0.28(-0.09)(+0.06); 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 are important for constraining formation and evolution theories for giant planets.
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    HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b : Four Warm Giant Planets Transiting K Dwarfs
    (2020) Hartman, J. D.; Jordán Colzani, Andrés Cristóbal; Bayliss, D.; Bakos, G. A.; Bento, J.; Bhatti, W.; Brahm Scott, Rafael; Csubry, Z.; Espinoza, N.; Henning, T.; Mancini, L.; Penev, K.; Rabus, Markus; Sarkis, P.; Suc, V.; de Val-Borro, M.; Zhou, G.; Crane, J. D.; Shectman, S.; Teske, J. K.; Wang, S. X.; Butler, R. P.; Lazar, J.; Papp, I.; Sari, P.; Anderson, D. R.; Hellier, C.; West, R. G.; Barkaoui, K.; Pozuelos, F. J.; Jehin, E.; Gillon, M.; Nielsen, L.; Lendl, M.; Udry, S.; Ricker, G. R.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Christiansen, J.; Crossfield, I. J. M.; Henze, C. E.; Jenkins, J. M.; Smith, J. C.; Ting, E. B.
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    HATS-71b : A Giant Planet Transiting an M3 Dwarf Star in TESS Sector 1
    (2020) Bakos, G. A.; Bayliss, D.; Bento, J.; Bhatti, W.; Brahm Scott, Rafael; Csubry, Z.; Espinoza, N.; Hartman, J. D.; Jordán Colzani, Andrés Cristóbal; Rabus, Markus; Henning, T.; Mancini, L.; Penev, K.; Sarkis, P.; Suc, V.; de Val-Borro, M.; Zhou, G.; Butler, R. P.; Crane, J.; Durkan, S.; Shectman, S.; Kim, J.; Lazar, J.; Papp, I.; Sari, P.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J.; Chacon, A. D.; Furesz, G.; Goeke, B.; Li, J.; Quinn, S.; Quintana, E. V.; Tenenbaum, P.; Teske, J.; Vezie, M.; Yu, L.; Stockdale, C.; Evans, P.; Relles, H. M.
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    HD 207897 b: A dense sub-Neptune transiting a nearby and bright K-type star
    (2022) Heidari, N.; Boisse, I; Orell-Miquel, J.; Hebrard, G.; Acuna, L.; Hara, N. C.; Lillo-Box, J.; Eastman, J. D.; Arnold, L.; Astudillo-Defru, N.; Adibekyan, V; Bieryla, A.; Bonfils, X.; Bouchy, F.; Barclay, T.; Brasseur, C. E.; Borgniet, S.; Bourrier, V; Buchhave, L.; Behmard, A.; Beard, C.; Batalha, N. M.; Courcol, B.; Cortes-Zuleta, P.; Collins, K.; Carmona, A.; Crossfield, I. J. M.; Chontos, A.; Delfosse, X.; Dalal, S.; Deleuil, M.; Demangeon, O. D. S.; Diaz, R. F.; Dumusque, X.; Daylan, T.; Dragomir, D.; Mena, E. Delgado; Dressing, C.; Dai, F.; Dalba, P. A.; Ehrenreich, D.; Forveille, T.; Fulton, B.; Fetherolf, T.; Gaisne, G.; Giacalone, S.; Riazi, N.; Hoyer, S.; Hobson, M. J.; Howard, A. W.; Huber, D.; Hill, M. L.; Hirsch, L. A.; Isaacson, H.; Jenkins, J.; Kane, S. R.; Kiefer, F.; Luque, R.; Latham, D. W.; Lubin, J.; Lopez, T.; Mousis, O.; Moutou, C.; Montagnier, G.; Mignon, L.; Mayo, A.; Mocnik, T.; Murphy, J. M. A.; Palle, E.; Pepe, F.; Petigura, E. A.; Rey, J.; Ricker, G.; Robertson, P.; Roy, A.; Rubenzahl, R. A.; Rosenthal, L. J.; Santerne, A.; Santos, N. C.; Sousa, S. G.; Stassun, K. G.; Stalport, M.; Scarsdale, N.; Strom, P. A.; Seager, S.; Segransan, D.; Tenenbaum, P.; Tronsgaard, R.; Udry, S.; Vanderspek, R.; Vakili, F.; Winn, J.; Weiss, L. M.
    We present the discovery and characterization of a transiting sub-Neptune that orbits the nearby (28 pc) and bright (V = 8.37) K0V star HD 207897 (TOI-1611) with a 16.20-day period. This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder, and HIRES high-precision spectrographs. We used EXOFASTv2 to model the parameters of the planet and its host star simultaneously, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50 +/- 0.08 R-E and a mass of either 14.4 +/- 1.6 M-E or 15.9 +/- 1.6 M-E with nearly equal probability. The two solutions correspond to two possibilities for the stellar activity period. The density accordingly is either 5.1 +/- 0.7 g cm(-3) or 5.5(-0.7)(+0.8) g cm(-3), making it one of the relatively rare dense sub-Neptunes. The existence of this dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2 < R-E < 4) population. The most likely scenario is that this planet has migrated to its current position.
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    Precise Transit and Radial-velocity Characterization of a Resonant Pair: The Warm Jupiter TOI-216c and Eccentric Warm Neptune TOI-216b
    (2021) Dawson, Rebekah I.; Huang, Chelsea X.; Brahm, Rafael; Collins, Karen A.; Hobson, Melissa J.; Jordan, Andres; Dong, Jiayin; Korth, Judith; Trifonov, Trifon; Abe, Lyu; Agabi, Abdelkrim; Bruni, Ivan; Butler, R. Paul; Barbieri, Mauro; Collins, Kevin I.; Conti, Dennis M.; Crane, Jeffrey D.; Crouzet, Nicolas; Dransfield, Georgina; Evans, Phil; Espinoza, Nestor; Gan, Tianjun; Guillot, Tristan; Henning, Thomas; Lissauer, Jack J.; Jensen, Eric L. N.; Sainte, Wenceslas Marie; Mekarnia, Djamel; Myers, Gordon; Nandakumar, Sangeetha; Relles, Howard M.; Sarkis, Paula; Torres, Pascal; Shectman, Stephen; Schmider, Francois-Xavier; Shporer, Avi; Stockdale, Chris; Teske, Johanna; Triaud, Amaury H. M. J.; Wang, Sharon Xuesong; Ziegler, Carl; Ricker, G.; Vanderspek, R.; Latham, David W.; Seager, S.; Winn, J.; Jenkins, Jon M.; Bouma, L. G.; Burt, Jennifer A.; Charbonneau, David; Levine, Alan M.; McDermott, Scott; McLean, Brian; Rose, Mark E.; Vanderburg, Andrew; Wohler, Bill
    TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations (TTVs). Precise characterization of the planets' masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial-velocity measurements using HARPS, FEROS, and the Planet Finder Spectrograph break that degeneracy, and an expanded TTV baseline from TESS and an ongoing ground-based transit observing campaign increase the precision of the mass and eccentricity measurements. We determine that TOI-216c is a warm Jupiter, TOI-216b is an eccentric warm Neptune, and that they librate in 2:1 resonance with a moderate libration amplitude of deg, a small but significant free eccentricity of for TOI-216b, and a small but significant mutual inclination of 12-39 (95% confidence interval). The libration amplitude, free eccentricity, and mutual inclination imply a disturbance of TOI-216b before or after resonance capture, perhaps by an undetected third planet.
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    The EXPLORE project.: I.: A deep search for transiting extrasolar planets
    (2003) Mallén-Ornelas, G.; Seager, S.; Yee, H.K.C.; Minniti, D.; Gladders, M.D.; Mallén-Fullerton, G.M.; Brown, T.M.
    Planet transit searches promise to be the next breakthrough for extrasolar planet detection and will bring the characterization of short-period planets into a new era. Every transiting planet discovered will have a measured radius, which will provide constraints on planet composition, evolution, and migration history. Together with radial velocity measurements, the absolute mass of every transiting planet will be determined. In this paper we discuss the design considerations of the Extrasolar Planet Occultation Research (EXPLORE) project, a series of transiting planet searches using 4 m class telescopes to continuously monitor a single field of stars in the Galactic plane in each similar to2 week observing campaign. We discuss the general factors that determine the efficiency and the number of planets found by a transit search, including time sampling strategy and field selection. The primary goal is to select the most promising planet candidates for radial velocity follow-up observations. We show that with very high photometric precision light curves that have frequent time sampling and at least two detected transits, it is possible to uniquely solve for the main parameters of the eclipsing system (including planet radius), based on several important assumptions about the central star. Together with a measured spectral type for the star, this unique solution for orbital parameters provides a powerful method for ruling out most contaminants to transiting planet candidates. For the EXPLORE project, radial velocity follow-up observations for companion mass determination of the best candidates are done on 8 m class telescopes within 2 or 3 months of the photometric campaigns. This same-season follow-up is made possible by the use of efficient pipelines to produce high-quality light curves within weeks of the observations. We conclude by presenting early results from our first search, EXPLORE I, in which we reached better than 1% rms photometric precision (measured over a full night) on similar to37,000 stars with 14.5less than or equal toIless than or equal to18.2.
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    TOI-150b and TOI-163b : two transiting hot Jupiters, one eccentric and one inflated, revealed by TESS near and at the edge of the JWST CVZ
    (2019) Kossakowski, D.; Espinoza, N.; Brahm Scott, Rafael; Jordán Colzani, Andrés Cristóbal; Henning, T.; Rojas, Felipe; Kurster, M.; Sarkis, P.; Schlecker, M.; Pozuelos, F. J.; Barkaoui, K.; Jehin, E.; Gillon, M.; Matthews, E.; Horch, E. P.; Ciardi, D. R.; Rossfield, I. J. M.; Gonzales, E.; Howell, S. B.; Matson, R.; Schlieder, J.; Jenkins, J.; Ricker, G.; Seager, S.; Winn, J. N.; Li, J.; Rose, M. E.; Smith, J. C.; Dynes, S.; Morgan, E.; Villaseñor, J. N.; Charbonneau, D.; Jaffe, T.; Yu, L.; Bakos, G.; Bhatti, W.; Bouchy, F.; Collins, K. A.; Collins, K. I.; Csubry, Z.; Evans, P.; Jensen, E. L. N.; Lovis, C.; Marmier, M.; Nielsen, L. D.; Osip, D.; Pepe, F.; Relles, H. M.; Segransan, D.; Shporer, A.; Stockdale, C.; Suc, V.; Turner, O.; Udry, S.
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    TOI-199 b: A Well-characterized 100 day Transiting Warm Giant Planet with TTVs Seen from Antarctica
    (2023) Hobson, Melissa J.; Trifonov, Trifon; Henning, Thomas; Jordan, Andres; Rojas, Felipe; Espinoza, Nestor; Brahm, Rafael; Eberhardt, Jan; Jones, Matias I.; Mekarnia, Djamel; Kossakowski, Diana; Schlecker, Martin; Pinto, Marcelo Tala; Torres Miranda, Pascal Jose; Abe, Lyu; Barkaoui, Khalid; Bendjoya, Philippe; Bouchy, Francois; Buttu, Marco; Carleo, Ilaria; Collins, Karen A.; Colon, Knicole D.; Crouzet, Nicolas; Dragomir, Diana; Dransfield, Georgina; Gasparetto, Thomas; Goeke, Robert F.; Guillot, Tristan; Guenther, Maximilian N.; Howard, Saburo; Jenkins, Jon M.; Korth, Judith; Latham, David W.; Lendl, Monika; Lissauer, Jack J.; Mann, Christopher R.; Mireles, Ismael; Ricker, George R.; Saesen, Sophie; Schwarz, Richard P.; Seager, S.; Sefako, Ramotholo; Shporer, Avi; Stockdale, Chris; Suarez, Olga; Tan, Thiam-Guan; J. Triaud, Amaury H. M.; Ulmer-Moll, Solene; Vanderspek, Roland; Winn, Joshua N.; Wohler, Bill; Zhou, George
    We present the spectroscopic confirmation and precise mass measurement of the warm giant planet TOI-199 b. This planet was first identified in TESS photometry and confirmed using ground-based photometry from ASTEP in Antarctica including a full 6.5 hr long transit, PEST, Hazelwood, and LCO; space photometry from NEOSSat; and radial velocities (RVs) from FEROS, HARPS, CORALIE, and CHIRON. Orbiting a late G-type star, TOI-199 b has a 104.854-0.002+0.001day period, a mass of 0.17 +/- 0.02 M J, and a radius of 0.810 +/- 0.005 R J. It is the first warm exo-Saturn with a precisely determined mass and radius. The TESS and ASTEP transits show strong transit timing variations (TTVs), pointing to the existence of a second planet in the system. The joint analysis of the RVs and TTVs provides a unique solution for the nontransiting companion TOI-199 c, which has a period of 273.69-0.22+0.26days and an estimated mass of 0.28-0.01+0.02MJ . This period places it within the conservative habitable zone.
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    TOI-222: a single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS
    (2019) Lendl, M.; Bouchy, F.; Gill, S.; Nielsen, L. D.; Turner, O.; Stassun, K.; Acton, J. S.; Anderson, D. R.; Armstrong, D. J.; Bayliss, D.; Belardi, C.; Bryant, E. M.; Burleigh, M. R.; Chaushev, A.; Casewell, S. L.; Cooke, B. F.; Eigmüller, P.; Gillen, E.; Goad, M. R.; Gunther, M. N.; Hagelberg, J.; Jenkins, J. S.; Louden, T.; Marmier, M.; McCormac, J.; Moyano, M.; Pollacco, D.; Raynard, L.; Tilbrook, R. H.; Udry, S.; Vines, J. I.; West, R. G.; Wheatley, P. J.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M.; Addison, B.; Briceño, C.; Brahm, R.; Caldwell, D. A.; Doty, J.; Espinoza, N.; Goeke, B.; Henning, T.; Jordán, A.; Krishnamurthy, A.; Law, N.; Morris, R.; Okumura, J.; Mann, A. W.; Rodriguez, J. E.; Sarkis, P.; Schlieder, J.; Twicken, J. D.; Villanueva, S.; Wittenmyer, R. A.; Wright, D. J.; Ziegle, C.
    We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based photometric detection of two subsequent transits. Our data show that the companion to TOI-222 is a low-mass star, with a radius of $0.18_{-0.10}^{+0.39}$ R⊙ and a mass of 0.23 ± 0.01 M⊙. This discovery showcases the ability to efficiently discover long-period systems from TESS single-transit events using a combination of radial velocity monitoring coupled with high-precision ground-based photometry.
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    TOI-481 b and TOI-892 b : Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite
    (2020) Brahm, R.; Nielsen, L. D.; Wittenmyer, R. A.; Wang, S. H.; Rodríguez, J. E.; Espinoza, N.; Jones Fernández, Matías Ignacio; Rojas Thomas, Felipe Eduardo; Vanzi, Leonardo; Zapata, Abner; Jordán Colzani, Andrés Cristóbal; Henning, T.; Hobson, M.; Kossakowski, D.; Sarkis, P.; Schlecker, M.; Trifonov, T.; Shahaf, S.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J. N.; Jenkins, J. M.; Addison, B. C.; Bakos, G. A.; Bhatti, W.; Bayliss, D.; Berlind, P.; Bieryla, A.; Bouchy, F.; Bowler, B. P.; Briceno, C.; Brown, T. M.; Bryant, E. M.; Caldwell, D. A.; Charbonneau, D.; Collins, K. A.; Davis, A. B.; Esquerdo, G. A.; Fulton, B. J.; Guerrero, N. M.; Henze, C. E.; Hogan, A.; Horner, J; Huang, C. X.; Irwin, J.; Kane, S. R.; Kielkopf, J.; Mann, A. W.
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    TOI-677b : A Warm Jupiter (P=11.2 days) on an Eccentric Orbit Transiting a Late F-type Star
    (2020) Jordán Colzani, Andrés Cristóbal; Brahm Scott, Rafael; Espinoza, N.; Henning, T.; Jones Fernández, Matías Ignacio; Kossakowski, D.; Sarkis, P.; Trifonov, T.; Rojas, Felipe; Torres, P.; Drass, Holger; Nandakumar, S.; Barbieri, M.; Davis, A.; Wang, S. H.; Bayliss, D.; Bouma, L.; Dragomir, D.; Eastman, J. D.; Daylan, T.; Guerrero, N.; Barclay, T.; Ting, E. B.; Henze, C. E.; Ricker, G.; Vanderspek, R.; Latham, D. W.; Seager, S.; Winn, J.; Jenkins, J. M.; Wittenmyer, R. A.; Bowler, B. P.; Crossfield, I.; Horner, J.; Kane, S. R.; Kielkopf, J. F.; Morton, T. D.; Plavchan, P.; Tinney, C. G.; Addison, B.; Mengel, M. W.; Okumura, J.; Shahaf, S.; Mazeh, T.; Rabus, Markus; Shporer, A.; Ziegler, C.; Mann, A. W.; Hart, R.