Abstract
We report on the discovery and validation of a two-planet system around a bright (V = 8.85 mag) early G dwarf (1.43 R⊙ , 1.15 M⊙ , TOI 2319) using data from NASA’s Transiting Exoplanet Survey Satellite (TESS). Three transit events from two planets were detected by citizen scientists in the month-long TESS light curve (sector 25), as part of the Planet Hunters TESS project. Modelling of the transits yields an orbital period of 11.6264+0.0022−0.0025 days and radius of 3.41+0.14−0.12 R⊕ for the inner planet, and a period in the range 19.26–35 days and a radius of 5.83+0.14−0.14 R⊕
for the outer planet, which was only seen to transit once. Each signal
was independently statistically validated, taking into consideration the
TESS light curve as well as the ground-based spectroscopic
follow-up observations. Radial velocities from HARPS-N and EXPRES yield a
tentative detection of planet b, whose mass we estimate to be 11.56+6.58−6.14 M⊕, and allow us to place an upper limit of 27.5 M⊕
(99 per cent confidence) on the mass of planet c. Due to the brightness
of the host star and the strong likelihood of an extended H/He
atmosphere on both planets, this system offers excellent prospects for
atmospheric characterisation and comparative planetology.
Original language | English |
---|---|
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 505 |
Issue number | 2 |
Pages (from-to) | 1827–1840 |
ISSN | 0035-8711 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- Methods
- Statistical
- Planets and satellites: detection
- Stars: fundamental parameters
- Stars: individual: TIC 349488688, HD152843