55 research outputs found
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 II: findings from the first two years of TESS
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230761.pdf (publisher's version ) (Open Access
Planet Hunters TESS IV: a massive, compact hierarchical triple star system TIC 470710327
We report the discovery and analysis of a massive, compact, hierarchical triple system (TIC 470710327) initially identified by citizen scientists in data obtained by NASA's Transiting Exoplanet Survey Satellite (TESS). Spectroscopic follow-up observations obtained with the HERMES spectrograph, combined with eclipse-timing variations (ETVs), confirm that the system is comprised of three OB stars, with a compact 1.10 d eclipsing binary and a non-eclipsing tertiary on a 52.04 d orbit. Dynamical modelling of the system (from radial velocity and ETVs) reveal a rare configuration wherein the tertiary star (O9.5-B0.5V; 14-17 M⊙) is more massive than the combined mass of the inner binary (10.9-13.2 M⊙). Given the high mass of the tertiary, we predict that this system will undergo multiple phases of mass transfer in the future, and likely end up as a double neutron star gravitational wave progenitor or an exotic Thorne-Żytkow object. Further observational characterization of this system promises constraints on both formation scenarios of massive stars as well as their exotic evolutionary end-products
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
The BaBar detector: Upgrades, operation and performance
Contains fulltext :
121729.pdf (preprint version ) (Open Access
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