Browsing by Author "Huang, Chelsea X."

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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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    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.