Serrano, Luisa Maria; Gandolfi, Davide; Mustill, Alexander J.; Barragán, Oscar; Korth, Judith; Dai, Fei; Redfield, Seth; Fridlund, Malcolm; Lam, Kristine W. F.; Díaz, Matías R.; Grziwa, Sascha; Collins, Karen A.; Livingston, John H.; Cochran, William D.; Hellier, Coel; Bellomo, Salvatore E.; Trifonov, Trifon; Rodler, Florian; Alarcon, Javier; Jenkins, Jon M.; Latham, David W.; Ricker, George; Seager, Sara; Vanderspeck, Roland; Winn, Joshua N.; Albrecht, Simon; Collins, Kevin I.; Csizmadia, Szilárd; Daylan, Tansu; Deeg, Hans J.; Esposito, Massimiliano; Fausnaugh, Michael; Georgieva, Iskra; Goffo, Elisa; Guenther, Eike; Hatzes, Artie P.; Howell, Steve B.; Jensen, Eric L. N.; Luque, Rafael; Mann, Andrew W.; Murgas, Felipe; Osborne, Hannah L. M.; Palle, Enric; Persson, Carina M.; Rowden, Pam; Rudat, Alexander; Smith, Alexis M. S.; Twicken, Joseph D.; Van Eylen, Vincent; Ziegler, Carl
It is commonly accepted that exoplanets with orbital periods shorter than one day, also known as ultra-short-period (USP) planets, formed further out within their natal protoplanetary disks before migrating to their current-day orbits via dynamical interactions. One of the most accepted theories suggests a violent scenario involving high-eccentricity migration followed by tidal circularization. Here we present the discovery of a four-planet system orbiting the bright (V = 10.5) K6 dwarf star TOI-500. The innermost planet is a transiting, Earth-sized USP planet with an orbital period of ~13 hours, a mass of 1.42 ± 0.18 M⊕, a radius of 1.16 6−0.058+0.061R⊕ ? and a mean density of 4.8 9−0.88+1.03g cm−3 ?. Via Doppler spectroscopy, we discovered that the system hosts 3 outer planets on nearly circular orbits with periods of 6.6, 26.2 and 61.3 days and minimum masses of 5.03 ± 0.41 M⊕, 33.12 ± 0.88 M⊕ and 15.0 5−1.11+1.12M⊕ ?, respectively. The presence of both a USP planet and a low-mass object on a 6.6-day orbit indicates that the architecture of this system can be explained via a scenario in which the planets started on low-eccentricity orbits then moved inwards through a quasi-static secular migration. Our numerical simulations show that this migration channel can bring TOI-500 b to its current location in 2 Gyr, starting from an initial orbit of 0.02 au. TOI-500 is the first four-planet system known to host a USP Earth analogue whose current architecture can be explained via a non-violent migration scenario.
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable