Browsing by Author "Torres, Pascal"

Now showing 1 - 8 of 8
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    A Pair of Warm Giant Planets near the 2:1 Mean Motion Resonance around the K-dwarf Star TOI-2202*
    (2021) Trifonov, Trifon; Brahm, Rafael; Espinoza, Nestor; Henning, Thomas; Jordan, Andres; Nesvorny, David; Dawson, Rebekah I.; Lissauer, Jack J.; Lee, Man Hoi; Kossakowski, Diana; Rojas, Felipe I.; Hobson, Melissa J.; Sarkis, Paula; Schlecker, Martin; Bitsch, Bertram; Bakos, Gaspar A.; Barbieri, Mauro; Bhatti, W.; Butler, R. Paul; Crane, Jeffrey D.; Nandakumar, Sangeetha; Diaz, Matias R.; Shectman, Stephen; Teske, Johanna; Torres, Pascal; Suc, Vincent; Vines, Jose I.; Wang, Sharon X.; Ricker, George R.; Shporer, Avi; Vanderburg, Andrew; Dragomir, Diana; Vanderspek, Roland; Burke, Christopher J.; Daylan, Tansu; Shiao, Bernie; Jenkins, Jon M.; Wohler, Bill; Seager, Sara; Winn, Joshua N.
    TOI-2202 b is a transiting warm Jovian-mass planet with an orbital period of P = 11.91 days identified from the Full Frame Images data of five different sectors of the TESS mission. Ten TESS transits of TOI-2202 b combined with three follow-up light curves obtained with the CHAT robotic telescope show strong transit timing variations (TTVs) with an amplitude of about 1.2 hr. Radial velocity follow-up with FEROS, HARPS, and PFS confirms the planetary nature of the transiting candidate (a (b) = 0.096 +/- 0.001 au, m (b) = 0.98 +/- 0.06 M (Jup)), and a dynamical analysis of RVs, transit data, and TTVs points to an outer Saturn-mass companion (a (c) = 0.155 +/- 0.002 au, m (c) = 0.37 +/- 0.10 M (Jup)) near the 2:1 mean motion resonance. Our stellar modeling indicates that TOI-2202 is an early K-type star with a mass of 0.82 M (circle dot), a radius of 0.79 R (circle dot), and solar-like metallicity. The TOI-2202 system is very interesting because of the two warm Jovian-mass planets near the 2:1 mean motion resonance, which is a rare configuration, and their formation and dynamical evolution are still not well understood.
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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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    An ultrahot Neptune in the Neptune desert
    (2020) Jenkins, James S.; Diaz, Matias R.; Kurtovic, Nicolas T.; Espinoza, Nestor; Vines, Jose I.; Rojas, Pablo A. Pena; Brahm, Rafael; Torres, Pascal; Cortes-Zuleta, Pia; Soto, Maritza G.; Lopez, Eric D.; King, George W.; Wheatley, Peter J.; Winn, Joshua N.; Ciardi, David R.; Ricker, George; Vanderspek, Roland; Latham, David W.; Seager, Sara; Jenkins, Jon M.; Beichman, Charles A.; Bieryla, Allyson; Burke, Christopher J.; Christiansen, Jessie L.; Henze, Christopher E.; Klaus, Todd C.; McCauliff, Sean; Mori, Mayuko; Narita, Norio; Nishiumi, Taku; Tamura, Motohide; de Leon, Jerome Pitogo; Quinn, Samuel N.; Villasenor, Jesus Noel; Vezie, Michael; Lissauer, Jack J.; Collins, Karen A.; Collins, Kevin I.; Isopi, Giovanni; Mallia, Franco; Ercolino, Andrea; Petrovich, Cristobal; Jordan, Andres; Acton, Jack S.; Armstrong, David J.; Bayliss, Daniel; Bouchy, Francois; Belardi, Claudia; Bryant, Edward M.; Burleigh, Matthew R.; Cabrera, Juan; Casewell, Sarah L.; Chaushev, Alexander; Cooke, Benjamin F.; Eigmueller, Philipp; Erikson, Anders; Foxell, Emma; Gansicke, Boris T.; Gill, Samuel; Gillen, Edward; Guenther, Maximilian N.; Goad, Michael R.; Hooton, Matthew J.; Jackman, James A. G.; Louden, Tom; McCormac, James; Moyano, Maximiliano; Nielsen, Louise D.; Pollacco, Don; Queloz, Didier; Rauer, Heike; Raynard, Liam; Smith, Alexis M. S.; Tilbrook, Rosanna H.; Titz-Weider, Ruth; Turner, Oliver; Udry, Stephane; Walker, Simon. R.; Watson, Christopher A.; West, Richard G.; Palle, Enric; Ziegler, Carl; Law, Nicholas; Mann, Andrew W.
    About 1 out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultrashort-period planet(1,2). All of the previously known ultrashort-period planets are either hot Jupiters, with sizes above 10 Earth radii (R-circle plus), or apparently rocky planets smaller than 2 R-circle plus. Such lack of planets of intermediate size (the `hot Neptune desert') has been interpreted as the inability of low-mass planets to retain any hydrogen/ helium (H/He) envelope in the face of strong stellar irradiation. Here we report the discovery of an ultrashort-period planet with a radius of 4.6 R-circle plus and a mass of 29 M-circle plus, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite(3) revealed transits of the bright Sun-like star LTT 9779 every 0.79 days. The planet's mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/He-rich envelope constituting 9.0(-2.9)(+2.7) % of the total mass. With an equilibrium temperature around 2,000 K, it is unclear how this `ultrahot Neptune' managed to retain such an envelope. Follow-up observations of the planet's atmosphere to better understand its origin and physical nature will be facilitated by the star's brightness (V-mag = 9.8).
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    Author correction: An ultrahot Neptune in the Neptune desert
    (2020) Jenkins, James S.; Díaz, Matías R.; Kurtovic, Nicolás T.; Espinoza, Néstor; Vines, Jose I.; Peña Rojas, Pablo A.; Brahm, Rafael; Torres, Pascal; Cortés Zuleta, Pía ; Soto, Maritza G.; López, Eric D.; King, George W.; Wheatley, Peter J.; Winn, Joshua N.; Ciardi, David R.; Ricker, George; Vanderspek, Roland; Latham, David W.; Seager, Sara; Jenkins, Jon M.; Beichman, Charles A.; Bieryla, Allyson; Burke, Christopher J.; Christiansen , Jessie L.; Henze, Christopher E.; Klaus, Todd C.; McCaulif, Sean; Mori, Mayuko; Narita, Norio; Nishiumi, Taku; Tamura, Motohide; Pitogo de Leon, Jerome; Quinn, Samuel N.; Villaseñor, Jesus Noel; Vezie, Michael; Lissauer, Jack J.; Collins, Karen A.; Collins, Kevin I.; Isopi, Giovanni; Mallia, Franco; Ercolino, Andrea; Petrovich, Cristobal; Jordán, Andrés; Acton, Jack S.; Armstrong, David J.; Bayliss, Daniel; Bouchy, François; Belardi, Claudia; Bryant, Edward M.; Burleigh, Matthew R.; Cabrera, Juan; Casewell, Sarah L.; Chaushev, Alexander; Cooke, Benjamin F.; Eigmüller, Philipp; Erikson, Anders; Foxell, Emma; Gänsicke, Boris T.; Gill, Samuel; Gillen, Edward; Günther, Maximilian N.; Goad, Michael R.; Hooton, Matthew J.; Jackman, James A. G.; Louden, Tom; McCormac, James; Moyano, Maximiliano; Nielsen, Louise D.; Pollacco, Don; Queloz, Didier; Rauer, Heike; Raynard, Liam; Smith, Alexis M. S.; Tilbrook, Rosanna H.; Titz Weider, Ruth; Turner, Oliver; Udry, Stéphane; Walker, Simon R.; Watson, Christopher A.; West, Richard G.; Palle, Enric; Ziegler, Carl; Law, Nicholas; Mann, Andrew W.
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    HD 1397b: a transiting warm giant planet orbiting a V = 7.8 mag sub-giant star discovered by TESS
    (2018) Brahm Scott, Rafael; Zapata, Abner; Jordán Colzani, Andrés Cristóbal; Vanzi, Leonardo; Rabus, Markus; Torres, Pascal
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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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    Three Long-period Transiting Giant Planets from TESS*
    (2023) Brahm, Rafael; Ulmer-Moll, Solene; Hobson, Melissa J.; Jordan, Andres; Henning, Thomas; Trifonov, Trifon; Jones, Matias I.; Schlecker, Martin; Espinoza, Nestor; Rojas, Felipe I.; Torres, Pascal; Sarkis, Paula; Tala, Marcelo; Eberhardt, Jan; Kossakowski, Diana; Munoz, Diego J.; Hartman, Joel D.; Boyle, Gavin; Suc, Vincent; Bouchy, Francois; Deline, Adrien; Chaverot, Guillaume; Grieves, Nolan; Lendl, Monika; Suarez, Olga; Guillot, Tristan; Triaud, Amaury H. M. J.; Crouzet, Nicolas; Dransfield, Georgina; Cloutier, Ryan; Barkaoui, Khalid; Schwarz, Rick P.; Stockdale, Chris; Harris, Mallory; Mireles, Ismael; Evans, Phil; Mann, Andrew W.; Ziegler, Carl; Dragomir, Diana; Villanueva, Steven; Mordasini, Christoph; Ricker, George; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Vezie, Michael; Youngblood, Allison; Daylan, Tansu; Collins, Karen A.; Caldwell, Douglas A.; Ciardi, David R.; Palle, Enric; Murgas, Felipe
    We report the discovery and orbital characterization of three new transiting warm giant planets. These systems were initially identified as presenting single-transit events in the light curves generated from the full-frame images of the Transiting Exoplanet Survey Satellite. Follow-up radial velocity measurements and additional light curves were used to determine the orbital periods and confirm the planetary nature of the candidates. The planets orbit slightly metal-rich late F- and early G-type stars. We find that TOI 4406b has a mass of M ( P ) = 0.30 +/- 0.04 M (J), a radius of R ( P ) = 1.00 +/- 0.02 R (J), and a low-eccentricity orbit (e = 0.15 +/- 0.05) with a period of P = 30.08364 +/- 0.00005 days. TOI 2338b has a mass of M ( P ) = 5.98 +/- 0.20 M (J), a radius of R ( P ) = 1.00 +/- 0.01 R (J), and a highly eccentric orbit (e = 0.676 +/- 0.002) with a period of P = 22.65398 +/- 0.00002 days. Finally, TOI 2589b has a mass of M ( P ) = 3.50 +/- 0.10 M (J), a radius of R ( P ) = 1.08 +/- 0.03 R (J), and an eccentric orbit (e = 0.522 +/- 0.006) with a period of P = 61.6277 +/- 0.0002 days. TOI 4406b and TOI 2338b are enriched in metals compared to their host stars, while the structure of TOI 2589b is consistent with having similar metal enrichment to its host star.
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    TOI-257b (HD 19916b): a warm sub-saturn orbiting an evolved F-type star
    (2021) Addison, Brett C.; Wright, Duncan J.; Nicholson, Belinda A.; Cale, Bryson; Mocnik, Teo; Huber, Daniel; Plavchan, Peter; Wittenmyer, Robert A.; Vanderburg, Andrew; Chaplin, William J.; Chontos, Ashley; Clark, Jake T.; Eastman, Jason D.; Ziegler, Carl; Brahm, Rafael; Carter, Bradley D.; Clerte, Mathieu; Espinoza, Nestor; Horner, Jonathan; Bentley, John; Jordan, Andres; Kane, Stephen R.; Kielkopf, John F.; Laychock, Emilie; Mengel, Matthew W.; Okumura, Jack; Stassun, Keivan G.; Bedding, Timothy R.; Bowler, Brendan P.; Burnelis, Andrius; Blanco-Cuaresma, Sergi; Collins, Michaela; Crossfield, Ian; Davis, Allen B.; Evensberget, Dag; Heitzmann, Alexis; Howell, Steve B.; Law, Nicholas; Mann, Andrew W.; Marsden, Stephen C.; Matson, Rachel A.; O'Connor, James H.; Shporer, Avi; Stevens, Catherine; Tinney, C. G.; Tylor, Christopher; Wang, Songhu; Zhang, Hui; Henning, Thomas; Kossakowski, Diana; Ricker, George; Sarkis, Paula; Schlecker, Martin; Torres, Pascal; Vanderspek, Roland; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Mireles, Ismael; Rowden, Pam; Pepper, Joshua; Daylan, Tansu; Schlieder, Joshua E.; Collins, Karen A.; Collins, Kevin, I; Tan, Thiam-Guan; Ball, Warrick H.; Basu, Sarbani; Buzasi, Derek L.; Campante, Tiago L.; Corsaro, Enrico; Gonzalez-Cuesta, L.; Davies, Guy R.; de Almeida, Leandro; do Nascimento, Jose-Dias, Jr.; Garcia, Rafael A.; Guo, Zhao; Handberg, Rasmus; Hekker, Saskia; Hey, Daniel R.; Kallinger, Thomas; Kawaler, Steven D.; Kayhan, Cenk; Kuszlewicz, James S.; Lund, Mikkel N.; Lyttle, Alexander; Mathur, Savita; Miglio, Andrea; Mosser, Benoit; Nielsen, Martin B.; Serenelli, Aldo M.; Aguirre, Victor Silva; Themessl, Nathalie
    We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the MINERVA-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of M-P = 0.138 +/- 0.023M(J) (43.9 +/- 7.3 M-circle plus), a radius of R-P = 0.639 +/- 0.013 R-J (7.16 +/- 0.15 R-circle plus), bulk density of 0.65(-0.11)(+0.12) (cgs), and period 18.38818(-0.00084)(+0.00085) days. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M-* = 1.390 +/- 0.046(Msun), R-* = 1.888 +/- 0.033 R-sun, T-eff = 6075 +/- 90 K, and vsin i = 11.3 +/- 0.5 kms(-1). Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a similar to 71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (similar to 100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.