19 research outputs found
Neuropsychiatric Symptom Burden across Neurodegenerative Disorders and its Association with Function
Planet Hunters TESS III: Two transiting planets around the bright G dwarf HD 152843
We report on the discovery and validation of a two-planet system around a
bright (V = 8.85 mag) early G dwarf (1.43 , 1.15 , 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 \Pb\ and radius
of for the inner planet, and a
period in the range 19.26-35 days and a radius of 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 , and allow us to place an upper limit of
(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
Planet Hunters Tess I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
We report on the discovery and validation of TOI 813 b (TIC55525572b), a transiting exoplanet identified by citizen scientists in data from NASA's Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant (R* = 1.94 R☉, M☉ = 1.32 M☉). It was observed almost continuously by TESS during its first year of operations, during which time four individual transit events were detected. The candidate passed all the standard light curve-based vetting checks, and ground-based follow-up spectroscopy and speckle imaging enabled us to place an upper limit of 2 MJup (99 per cent confidence) on the mass of the companion, and to statistically validate its planetary nature. Detailed modelling of the transits yields a period of 83.8911+0.0027-0.0031 d, a planet radius of 6.71 ± 0.38 R⊕ and a semimajor axis of 0.423+0031-0.037 AU. The planet's orbital period combined with the evolved nature of the host star places this object in a relatively underexplored region of parameter space. We estimate that TOI 813 b induces a reflex motion in its host star with a semi-amplitude of ∼6 m s−1, making this a promising system to measure the mass of a relatively long-period transiting planet
Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
We report on the discovery and validation of TOI 813b (TIC 55525572 b), a
transiting exoplanet identified by citizen scientists in data from NASA's
Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by
the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag)
subgiant (, ). It was observed
almost continuously by TESS during its first year of operations, during which
time four individual transit events were detected. The candidate passed all the
standard light curve-based vetting checks, and ground-based follow-up
spectroscopy and speckle imaging enabled us to place an upper limit of (99 % confidence) on the mass of the companion, and to statistically
validate its planetary nature. Detailed modelling of the transits yields a
period of days, a planet radius of , and a semi major axis of AU. The planet's orbital period combined with the evolved nature of the host
star places this object in a relatively under-explored region of parameter
space. We estimate that TOI-813b induces a reflex motion in its host star with
a semi-amplitude of ms, making this system a promising target to
measure the mass of a relatively long-period transiting planet.Comment: Accepted for publication in MNRAS (16 pages, 10 figures, 3 tables