The EBLM project : III. A Saturn-size low-mass star at the hydrogen-burning limit
Abstract
We report the discovery of an eclipsing binary system with mass-ratio q ∼ 0.07. After identifying a periodic photometric signal received by WASP, we obtained CORALIE spectroscopic radial velocities and follow-up light curves with the Euler and TRAPPIST telescopes. From a joint fit of these data we determine that EBLM J0555-57 consists of a sun-like primary star that is eclipsed by a low-mass companion, on a weakly eccentric 7.8-day orbit. Using a mass estimate for the primary star derived from stellar models, we determine a companion mass of 85 ± 4 MJup (0.081 M⊙) and a radius of 0.84+ 0.14 -0.04RJup (0.084 R⊙) that is comparable to that of Saturn. EBLM J0555-57Ab has a surface gravity log g2 =5.50+ 0.03 -0.13 and is one of the densest non-stellar-remnant objects currently known. These measurements are consistent with models of low-mass stars.
Citation
Von Boetticher , A , Triaud , A H M J , Queloz , DI , Gill , S , Lendl , M , Delrez , L , Anderson , D R , Cameron , A C , Faedi , F , Gillon , M , Chew , Y G M , Hebb , L , Hellier , C , Jehin , E , Maxted , P F L , Martin , D V , Pepe , F , Pollacco , D , Ségransan , D , Smalley , B , Udry , S & West , R 2017 , ' The EBLM project : III. A Saturn-size low-mass star at the hydrogen-burning limit ' , Astronomy & Astrophysics , vol. 604 , L6 . https://doi.org/10.1051/0004-6361/201731107
Publication
Astronomy & Astrophysics
Status
Peer reviewed
ISSN
0004-6361Type
Journal article
Description
This work was partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127).Collections
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