Browsing by Author "Nesvorny, David"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    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.