Browsing by Author "Collins, Karen A."

Now showing 1 - 17 of 17
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    A Large Ground-based Observing Campaign of the Disintegrating Planet K2-22b
    (2018) Colon, Knicole D.; Zhou, George; Shporer, Avi; Collins, Karen A.; Bieryla, Allyson; Espinoza, Nestor; Murgas, Felipe; Pattarakijwanich, Petchara; Awiphan, Supachai; Armstrong, James D.; Bailey, Jeremy; Barentsen, Geert; Bayliss, Daniel; Chakpor, Anurak; Cochran, William D.; Dhillon, Vikram S.; Horne, Keith; Ireland, Michael; Kedziora-Chudczer, Lucyna; Kielkopf, John F.; Komonjinda, Siramas; Latham, David W.; Marsh, Tom R.; Mkrtichian, David E.; Palle, Enric; Ruffolo, David; Sefako, Ramotholo; Tinney, Chris G.; Wannawichian, Suwicha; Yuma, Suraphong
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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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    Evolution of BD-14 3065b (TOI-4987b) from giant planet to brown dwarf as possible evidence of deuterium burning at old stellar ages
    (2024) Subjak, Jan; Latham, David W.; Quinn, Samuel N.; Berlind, Perry; Calkins, Michael L.; Esquerdo, Gilbert A.; Brahm, Rafael; Caballero, Jose A.; Collins, Karen A.; Guenther, Eike; Janik, Jan; Kabath, Petr; Schwarz, Richard P.; Tan, Thiam-Guan; Vanzi, Leonardo; Zambelli, Roberto; Ziegler, Carl; Jenkins, Jon M.; Mireles, Ismael; Seager, Sara; Shporer, Avi; Striegel, Stephanie; Winn, Joshua N.
    The present study confirms BD-14 3065b as a transiting planet-brown dwarf in a triple-star system, with a mass near the deuterium-burning boundary. BD-14 3065b has the largest radius observed within the sample of giant planets and brown dwarfs around post-main sequence stars. Its orbital period is 4.3 days and it transits a subgiant F-type star with a mass of M-* = 1.41 +/- 0.05 M-circle dot, a radius of R-* = 2.35 +/- 0.08 R-circle dot, an effective temperature of T-eff = 6935 +/- 90 K, and a metallicity of -0.34 +/- 0.05 dex. By combining TESS photometry with high-resolution spectra acquired with the TRES and Pucheros+ spectrographs, we measured a mass of M-p = 12.37 +/- 0.92 M-Jup and a radius of R-p = 1.926 +/- 0.094 R-Jup. Our discussion of potential processes that could be responsible for the inflated radius led us to conclude that deuterium burning is a plausible explanation for the heating taking place in BD-14 3065b's interior. Detections of the secondary eclipse with TESS photometry enabled a precise determination of the eccentricity, e(p) = 0.066 +/- 0.011, and reveal that BD-14 3065b has a brightness temperature of 3520 +/- 130 K. With its unique characteristics, BD-14 3065b presents an excellent opportunity to study its atmosphere via thermal emission spectroscopy.
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    HD 2685 b: a hot Jupiter orbiting an early F-type star detected by TESS
    (2019) Jones, Matias, I; Brahm, Rafael; Espinoza, Nestor; Wang, Songhu; Shporer, Avi; Henning, Thomas; Jordan, Andres; Sarkis, Paula; Paredes, Leonardo A.; Hodari-Sadiki, James; Henrys, Todd; Cruz, Bryndis; Nielsen, Louise D.; Bouchy, Francois; Pepe, Francesco; Segransan, Damien; Turner, Oliver; Udry, Stephane; Marmier, Maxime; Lovis, Christophe; Bakos, Gaspar; Osip, David; Suc, Vincent; Ziegler, Carl; Tokovinin, Andrei; Law, Nick M.; Mann, Andrew W.; Relles, Howard; Collins, Karen A.; Bayliss, Daniel; Sedaghati, Elyar; Latham, David W.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Smith, Jeffrey C.; Davies, Misty; Tenenbaum, Peter; Dittmann, Jason; Vanderburg, Andrew; Christiansen, Jessie L.; Haworth, Kari; Doty, John; Furesz, Gabor; Laughlin, Greg; Matthews, Elisabeth; Crossfield, Ian; Howell, Steve; Ciardi, David; Gonzales, Erica; Matson, Rachel; Beichman, Charles; Schlieder, Joshua
    We report on the confirmation of a transiting giant planet around the relatively hot (T-eff = 6801 +/- 76 K) star HD 2685, whose transit signal was detected in Sector 1 data of NASA's TESS mission. We confirmed the planetary nature of the transit signal using Doppler velocimetric measurements with CHIRON, CORALIE, and FEROS, as well as using photometric data obtained with the Chilean-Hungarian Automated Telescope and the Las Cumbres Observatory. From the joint analysis of photometry and radial velocities, we derived the following parameters for HD 2685 b: P =4.12688(-0.00004)(+0.00005) days, e =0.091(-0.047)(+0.039), Mp = 1.17 +/- 0.12 M-J, and R-p =1.44 +/- 0.05 R-J. This system is a typical example of an inflated transiting hot Jupiter in a low-eccentricity orbit. Based on the apparent visual magnitude (V = 9.6 mag) of the host star, this is one of the brightest known stars hosting a transiting hot Jupiter, and it is a good example of the upcoming systems that will be detected by TESS during the two-year primary mission. This is also an excellent target for future ground- and space-based atmospheric characterization as well as a good candidate for measuring the projected spin-orbit misalignment angle through the Rossiter-McLaughlin effect.
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    TESS spots a mini- interior to a hot saturn in the TOI-2000 system
    (2023) Sha, Lizhou; Vanderburg, Andrew M.; Huang, Chelsea X.; Armstrong, David J.; Brahm, Rafael; Giacalone, Steven; Wood, Mackenna L.; Collins, Karen A.; Nielsen, Louise D.; Hobson, Melissa J.; Ziegler, Carl; Howell, Steve B.; Torres-Miranda, Pascal; Mann, Andrew W.; Zhou, George; Delgado-Mena, Elisa; Rojas, Felipe, I; Abe, Lyu; Trifonov, Trifon; Adibekyan, Vardan; Sousa, Sergio G.; Fajardo-Acosta, Sergio B.; Guillot, Tristan; Howard, Saburo; Littlefield, Colin; Hawthorn, Faith; Schmider, Francois-Xavier; Eberhardt, Jan; Tan, Thiam-Guan; Osborn, Ares; Schwarz, Richard P.; Strom, Paul; Jordan, Andres; Wang, Gavin; Henning, Thomas; Massey, Bob; Law, Nicholas; Stockdale, Chris; Furlan, Elise; Srdoc, Gregor; Wheatley, Peter J.; Navascues, David Barrado; Lissauer, Jack J.; Stassun, Keivan G.; Ricker, George R.; Vanderspek, Roland K.; Latham, David W.; Winn, Joshua N.; Seager, Sara; Jenkins, Jon M.; Barclay, Thomas; Bouma, Luke G.; Christiansen, Jessie L.; Guerrero, Natalia; Rose, Mark E.
    Hot jupiters (P < 10 d, M > 60 M.) are almost always found alone around their stars, but four out of hundreds known have inner companion planets. These rare companions allow us to constrain the hot jupiter's formation history by ruling out high-eccentricity tidal migration. Less is known about inner companions to hot Saturn-mass planets. We report here the discovery of the TOI-2000 system, which features a hot Saturn-mass planet with a smaller inner companion. The mini-neptune TOI-2000 b (2.70 +/- 0.15 R-circle plus, 11.0 +/- 2.4 M.) is in a 3.10-d orbit, and the hot saturn TOI-2000 c (8.14(+0.31) (-0.30) R-circle plus, 81.7(-4.6)(+4.7) M.) is in a 9.13-d orbit. Both planets transit their host star TOI-2000 (TIC 371188886, V = 10.98, TESS magnitude = 10.36), a metal-rich ([Fe/H] = 0.439 (+0.041)(-0.043)) G dwarf 173 pc away. TESS observed the two planets in sectors 9-11 and 36-38, and we followed up with groundbased photometry, spectroscopy, and speckle imaging. Radial velocities from CHIRON, FEROS, and HARPS allowed us to confirm both planets by direct mass measurement. In addition, we demonstrate constraining planetary and stellar parameters with MIST stellar evolutionary tracks through Hamiltonian Monte Carlo under the PYMC framework, achieving higher sampling efficiency and shorter run time compared to traditional Markov chain Monte Carlo. Having the brightest host star in the V band among similar systems, TOI-2000 b and c are superb candidates for atmospheric characterization by the JWST, which can potentially distinguish whether they formed together or TOI-2000 c swept along material during migration to form TOI-2000 b.
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    Mass determination of two Jupiter-sized planets orbiting slightly evolved stars: TOI-2420 b and TOI-2485 b
    (2024) Carleo, Ilaria; Barragan, Oscar; Persson, Carina M.; Fridlund, Malcolm; Lam, Kristine W. F.; Messina, Sergio; Gandolfi, Davide; Smith, Alexis M. S.; Johnson, Marshall C.; Cochran, William; Osborne, Hannah L. M.; Brahm, Rafael; Ciardi, David R.; Collins, Karen A.; Everett, Mark E.; Giacalone, Steven; Guenther, Eike W.; Hatzes, Artie; Hellier, Coel; Horner, Jonathan; Kabath, Petr; Korth, Judith; MacQueen, Phillip; Masseron, Thomas; Murgas, Felipe; Nowak, Grzegorz; Rodriguez, Joseph E.; Watkins, Cristilyn N.; Wittenmyer, Rob; Zhou, George; Ziegler, Carl; Bieryla, Allyson; Boyd, Patricia T.; Clark, Catherine A.; Dressing, Courtney D.; Eastman, Jason D.; Eberhardt, Jan; Endl, Michael; Espinoza, Nestor; Fausnaugh, Michael; Guerrero, Natalia M.; Henning, Thomas; Hesse, Katharine; Hobson, Melissa J.; Howell, Steve B.; Jordan, Andres; Latham, David W.; Lund, Michael B.; Mireles, Ismael; Narita, Norio; Tala Pinto, Marcelo; Pugh, Teznie; Quinn, Samuel N.; Ricker, George; Rodriguez, David R.; Rojas, Felipe I.; Rose, Mark E.; Rudat, Alexander; Sarkis, Paula; Savel, Arjun B.; Schlecker, Martin; Schwarz, Richard P.; Seager, Sara; Shporer, Avi; Smith, Jeffrey C.; Stassun, Keivan G.; Stockdale, Chris; Trifonov, Trifon; Vanderspek, Roland; Winn, Joshua N.; Wright, Duncan
    Context. Hot and warm Jupiters might have undergone the same formation and evolution path, but the two populations exhibit different distributions of orbital parameters. This challenges our understanding of their actual origin. Aims. We report the results of our warm Jupiters survey, which was carried out with the CHIRON spectrograph within the KESPRINT collaboration. We addressed the question of the population origin by studying two planets that might help to bridge the gap between the two populations. Methods. We confirm two planets and determine their mass. One is a hot Jupiter (with an orbital period shorter than 10 days), TOI-2420 b, and the other is a warm Jupiter, TOI-2485 b. We analyzed them using a wide variety of spectral and photometric data in order to characterize these planetary systems. Results. We found that TOI-2420 b has an orbital period of P-b=5.8 days, a mass of M-b=0.9 M-J, and a radius of R-b=1.3 R-J, with a planetary density of 0.477 g cm(-3). TOI-2485 b has an orbital period of P-b=11.2 days, a mass of M-b=2.4 M-J, and a radius of R-b=1.1 R-J with a density of 2.36 g cm(-3). Conclusions. With the current parameters, the migration history for TOI-2420 b and TOI-2485 b is unclear: Scenarios of a high-eccentricity migration cannot be ruled out, and the characteristics of TOI-2485 b even support this scenario.
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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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    TESS Delivers Five New Hot Giant Planets Orbiting Bright Stars from the Full-frame Images
    (2021) Rodriguez, Joseph E.; Quinn, Samuel N.; Zhou, George; Vanderburg, Andrew; Nielsen, Louise D.; Wittenmyer, Robert A.; Brahm, Rafael; Reed, Phillip A.; Huang, Chelsea X.; Vach, Sydney; Ciardi, David R.; Oelkers, Ryan J.; Stassun, Keivan G.; Hellier, Coel; Gaudi, B. Scott; Eastman, Jason D.; Collins, Karen A.; Bieryla, Allyson; Christian, Sam; Latham, David W.; Carleo, Ilaria; Wright, Duncan J.; Matthews, Elisabeth; Gonzales, Erica J.; Ziegler, Carl; Dressing, Courtney D.; Howell, Steve B.; Tan, Thiam-Guan; Wittrock, Justin; Plavchan, Peter; McLeod, Kim K.; Baker, David; Wang, Gavin; Radford, Don J.; Schwarz, Richard P.; Esposito, Massimiliano; Ricker, George R.; Vanderspek, Roland K.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Addison, Brett; Anderson, D. R.; Barclay, Thomas; Beatty, Thomas G.; Berlind, Perry; Bouchy, Francois; Bowen, Michael; Bowler, Brendan P.; Brasseur, C. E.; Briceno, Cesar; Caldwell, Douglas A.; Calkins, Michael L.; Cartwright, Scott; Chaturvedi, Priyanka; Chaverot, Guillaume; Chimaladinne, Sudhish; Christiansen, Jessie L.; Collins, Kevin I.; Crossfield, Ian J. M.; Eastridge, Kevin; Espinoza, Nestor; Esquerdo, Gilbert A.; Feliz, Dax L.; Fenske, Tyler; Fong, William; Gan, Tianjun; Giacalone, Steven; Gill, Holden; Gordon, Lindsey; Granados, A.; Grieves, Nolan; Guenther, Eike W.; Guerrero, Natalia; Henning, Thomas; Henze, Christopher E.; Hesse, Katharine; Hobson, Melissa J.; Horner, Jonathan; James, David J.; Jensen, Eric L. N.; Jimenez, Mary; Jordan, Andres; Kane, Stephen R.; Kielkopf, John; Kim, Kingsley; Kuhn, Rudolf B.; Latouf, Natasha; Law, Nicholas M.; Levine, Alan M.; Lund, Michael B.; Mann, Andrew W.; Mao, Shude; Matson, Rachel A.; Mengel, Matthew W.; Mink, Jessica; Newman, Patrick; O'Dwyer, Tanner; Okumura, Jack; Palle, Enric; Pepper, Joshua; Quintana, Elisa V.; Sarkis, Paula; Savel, Arjun B.; Schlieder, Joshua E.; Schnaible, Chloe; Shporer, Avi; Sefako, Ramotholo; Seidel, Julia V.; Siverd, Robert J.; Skinner, Brett; Stalport, Manu; Stevens, Daniel J.; Stibbards, Caitlin; Tinney, C. G.; West, R. G.; Yahalomi, Daniel A.; Zhang, Hui
    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 Working Group. The planets are all Jovian size (R-P = 1.01-1.77 R-J) and have masses that range from 0.85 to 6.33 M-J. The host stars of these systems have F and G spectral types (5595 <= T-eff <= 6460 K) and are all relatively bright (9.5 < V < 10.8, 8.2 < K < 9.3), making them well suited for future detailed characterization efforts. Three of the systems in our sample (TOI-640 b, TOI-1333 b, and TOI-1601 b) orbit subgiant host stars (log g < 4.1). TOI-640 b is one of only three known hot Jupiters to have a highly inflated radius (R-P > 1.7 R-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(-0.30)(+) (0.28) M-J and a statistically significant, nonzero orbital eccentricity of e = 0.074(-0.022)(+) (0.021). 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 analog. NASA's TESS mission is continuing to increase the sample of well-characterized hot and warm Jupiters, complementing its primary mission goals.
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    TESS Giants Transiting Giants. I.: A Noninflated Hot Jupiter Orbiting a Massive Subgiant
    (2022) Saunders, Nicholas; Grunblatt, Samuel K.; Huber, Daniel; Collins, Karen A.; Jensen, Eric L. N.; Vanderburg, Andrew; Brahm, Rafael; Jordan, Andres; Espinoza, Nestor; Henning, Thomas; Hobson, Melissa J.; Quinn, Samuel N.; Zhou, George; Butler, R. Paul; Crause, Lisa; Kuhn, Rudi B.; Mogotsi, K. Moses; Hellier, Coel; Angus, Ruth; Hattori, Soichiro; Chontos, Ashley; Ricker, George R.; Jenkins, Jon M.; Tenenbaum, Peter; Latham, David W.; Seager, Sara; Vanderspek, Roland K.; Winn, Joshua N.; Stockdale, Chris; Cloutier, Ryan
    While the population of confirmed exoplanets continues to grow, the sample of confirmed transiting planets around evolved stars is still limited. We present the discovery and confirmation of a hot Jupiter orbiting TOI-2184 (TIC 176956893), a massive evolved subgiant (M-* = 1.53 +/- 0.12 M-circle dot, R-* = 2.90 +/- 0.14 R-circle dot) in the Transiting Exoplanet Survey Satellite (TESS) Southern Continuous Viewing Zone. The planet was flagged as a false positive by the TESS Quick-Look Pipeline due to periodic systematics introducing a spurious depth difference between even and odd transits. Using a new pipeline to remove background scattered light in TESS Full Frame Image data, we combine space-based TESS photometry, ground-based photometry, and ground-based radial velocity measurements to report a planet radius of R (p) = 1.017 +/- 0.051 R (J) and mass of M (p) = 0.65 +/- 0.16 M (J) . For a planet so close to its star, the mass and radius of TOI-2184b are unusually well matched to those of Jupiter. We find that the radius of TOI-2184b is smaller than theoretically predicted based on its mass and incident flux, providing a valuable new constraint on the timescale of post-main-sequence planet inflation. The discovery of TOI-2184b demonstrates the feasibility of detecting planets around faint (TESS magnitude > 12) post-main-sequence stars and suggests that many more similar systems are waiting to be detected in the TESS FFIs, whose confirmation may elucidate the final stages of planetary system evolution.
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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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    Three Saturn-mass planets transiting F-type stars revealed with TESS and HARPS TOI-615b, TOI-622b, and TOI-2641b
    (2023) Psaridi, Angelica; Bouchy, Francois; Lendl, Monika; Akinsanmi, Babatunde; Stassun, Keivan G.; Smalley, Barry; Armstrong, David J.; Howard, Saburo; Ulmer-Moll, Solene; Grieves, Nolan; Barkaoui, Khalid; Rodriguez, Joseph E.; Bryant, Edward M.; Suarez, Olga; Guillot, Tristan; Evans, Phil; Attia, Omar; Wittenmyer, Robert A.; Yee, Samuel W.; Collins, Karen A.; Zhou, George; Galland, Franck; Parc, Lena; Udry, Stephane; Figueira, Pedro; Ziegler, Carl; Mordasini, Christoph; Winn, Joshua N.; Seager, Sara; Jenkins, Jon M.; Twicken, Joseph D.; Brahm, Rafael; Jones, Matias, I; Abe, Lyu; Addison, Brett T.; Briceno, Cesar I.; Briegal, Joshua; Collins, Kevin; Daylan, Tansu; Eigmueller, Phillip M.; Furesz, Gabor; Guerrero, Natalia; Hagelberg, Janis; Heitzmann, Alexis X.; Hounsell, Rebekah; Huang, Chelsea M.; Krenn, Andreas W.; Law, Nicholas; Mann, Andrew; McCormac, James; Mekarnia, Djamel D.; Mounzer, Dany; Nielsen, Louise R.; Osborn, Ares; Reinarz, Yared A.; Sefako, Ramotholo; Steiner, Michal I.; Strom, Paul A.; Triaud, Amaury H. M. J.; Vanderspek, Roland; Vanzi, Leonardo; Vines, Jose; Watson, Christopher; Wright, Duncan; Zapata, Abner
    While the sample of confirmed exoplanets continues to grow, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (similar to 1277 F-circle dot) and bloated Saturn-mass planet (1.69(-0.06)(+0.05) R-Jup and 0.43(-0.08)(+0.09) M-Jup) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82(-0.03)(+0.03) R-Jup and a mass of 0.30(-0.08)(+0.07) M-Jup in a 6.40 day orbit. Despite its high insolation flux (similar to 600 F-circle dot), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39(-0.04)(+0.02) M-Jup planet in a 4.88 day orbit with a grazing transit (b = 1.04(-0.06)(+0.05)) that results in a poorly constrained radius of 1.61(-0.64)(+0.46) R-Jup. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation, and migration of exoplanets across various stellar types.
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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-2525 b and c: A Pair of Massive Warm Giant Planets with Strong Transit Timing Variations Revealed by TESS
    (2023) Trifonov, Trifon; Brahm, Rafael; Jordan, Andres; Hartogh, Christian; Henning, Thomas; Hobson, Melissa J.; Schlecker, Martin; Howard, Saburo; Reichardt, Finja; Espinoza, Nestor; Lee, Man Hoi; Nesvorny, David; Rojas, Felipe I.; Barkaoui, Khalid; Kossakowski, Diana; Boyle, Gavin; Dreizler, Stefan; Kuerster, Martin; Heller, Rene; Guillot, Tristan; Triaud, Amaury H. M. J.; Abe, Lyu; Agabi, Abdelkrim; Bendjoya, Philippe; Crouzet, Nicolas; Dransfield, Georgina; Gasparetto, Thomas; Guenther, Maximilian N.; Marie-Sainte, Wenceslas; Mekarnia, Djamel; Suarez, Olga; Teske, Johanna; Butler, R. Paul; Crane, Jeffrey D.; Shectman, Stephen; Ricker, George R.; Shporer, Avi; Vanderspek, Roland; Jenkins, Jon M.; Wohler, Bill; Collins, Karen A.; Collins, Kevin I.; Ciardi, David R.; Barclay, Thomas; Mireles, Ismael; Seager, Sara; Winn, Joshua N.
    The K-type star TOI-2525 has an estimated mass of M = 0.849(-0.033)(+0.024) M-circle dot and radius of R = 0.785(-0.007)(+0.007) R-circle dot observed by the TESS mission in 22 sectors (within sectors 1 and 39). The TESS light curves yield significant transit events of two companions, which show strong transit timing variations (TTVs) with a semiamplitude of similar to 6 hr. We performed TTV dynamical and photodynamical light-curve analysis of the TESS data combined with radial velocity measurements from FEROS and PFS, and we confirmed the planetary nature of these companions. The TOI-2525 system consists of a transiting pair of planets comparable to Neptune and Jupiter with estimated dynamical masses of m(b) = 0.088(-0.004)(+0.005) and m(c) = 0.709(-0.033)(+0.034) M-Jup, radii of r(b) = 0.88(-0.02)(+0.02) and r(c) = 0.98(-0.02)(+0.02) R-Jup, and orbital periods of P-b = 23.288(-0.002)(+0.001) and P-c = 49.260(-0.001)(+0.001) days for the inner and outer planet, respectively. The period ratio is close to the 2:1 period commensurability, but the dynamical simulations of the system suggest that it is outside the mean-motion resonance (MMR) dynamical configuration. Object TOI-2525 b is among the lowest-density Neptune-mass planets known to date, with an estimated median density of rho(b) = 0.174(-0.015)(+0.016) g cm(-3). The TOI-2525 system is very similar to the other K dwarf systems discovered by TESS, TOI-2202 and TOI-216, which are composed of almost identical K dwarf primaries and two warm giant planets near the 2:1 MMR.
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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.
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    TOpI-2447 b / NGTS-29 b: a 69-day Saturn around a Solar analogue
    (2024) Gill, Samuel; Bayliss, Daniel; Ulmer-Moll, Solene; Wheatley, Peter J.; Brahm, Rafael; Anderson, David R.; Armstrong, David; Apergis, Ioannis; Alves, Douglas R.; Burleigh, Matthew R.; Butler, R. P.; Bouchy, Francois; Battley, Matthew P.; Bryant, Edward M.; Bieryla, Allyson; Crane, Jeffrey D.; Collins, Karen A.; Casewell, Sarah L.; Carleo, Ilaria; Claringbold, Alastair B.; Dalba, Paul A.; Dragomir, Diana; Eigmueller, Philipp; Eberhardt, Jan; Fausnaugh, Michael; Gunther, Maximilian N.; Grieves, Nolan; Goad, Michael R.; Gillen, Edward; Hagelberg, Janis; Hobson, Melissa; Hedges, Christina; Henderson, Beth A.; Hawthorn, Faith; Henning, Thomas; Jones, Matias, I; Jordan, Andres; Jenkins, James S.; Kunimoto, Michelle; Krenn, Andreas F.; Kendall, Alicia; Lendl, Monika; McCormac, James; Moyano, Maximiliano; Torres-Miranda, Pascal; Nielsen, Louise D.; Osborn, Ares; Otegi, Jon; Osborn, Hugh; Quinn, Samuel N.; Rodriguez, Joseph E.; Ramsay, Gavin; Schlecker, Martin; Shectman, Stephen A.; Seager, Sara; Tilbrook, Rosanna H.; Trifonov, Trifon; Teske, Johanna K.; Udry, Stephane; Vines, Jose, I; West, Richard R.; Wohler, Bill; Winn, Joshua N.; Wang, Sharon X.; Zhou, George; Zivave, Tafadzwa
    Discovering transiting exoplanets with relatively long orbital periods (>10 d) is crucial to facilitate the study of cool exoplanet atmospheres (T-eq < 700 K) and to understand exoplanet formation and inward migration further out than typical transiting exoplanets. In order to discover these longer period transiting exoplanets, long-term photometric, and radial velocity campaigns are required. We report the discovery of TOI-2447 b (=NGTS-29 b), a Saturn-mass transiting exoplanet orbiting a bright (T = 10.0) Solar-type star (T-eff = 5730 K). TOI-2447 b was identified as a transiting exoplanet candidate from a single transit event of 1.3 per cent depth and 7.29 h duration in TESS Sector 31 and a prior transit event from 2017 in NGTS data. Four further transit events were observed with NGTS photometry which revealed an orbital period of P = 69.34 d. The transit events establish a radius for TOI-2447 b of 0.865 +/- 0.010 R-J, while radial velocity measurements give a mass of 0.386 +/- 0.025 M-J. The equilibrium temperature of the planet is 414 K, making it much cooler than the majority of TESS planet discoveries. We also detect a transit signal in NGTS data not caused by TOI-2447 b, along with transit timing variations and evidence for a similar to 150 d signal in radial velocity measurements. It is likely that the system hosts additional planets, but further photometry and radial velocity campaigns will be needed to determine their parameters with confidence. TOI-2447 b/NGTS-29 b joins a small but growing population of cool giants that will provide crucial insights into giant planet composition and formation mechanisms.