Abstract
We report the discovery of an eclipsing binary system with mass-ratio q tilde 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 plusmn 4 M$_Jup$ (0.081 M$_⊙$) and a radius of 0.84$^+ 0.14$$_-0.04$R$_Jup$ (0.084 R$_⊙$) that is comparable to that of Saturn. EBLM J0555-57Ab has a surface gravity log g$_2$ =5.50$^+ 0.03$$_-0.13$ and is one of the densest non-stellar-remnant objects currently known. These measurements are consistent with models of low-mass stars. The photometry tables and radial velocities are only available at the CDS and on demand via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/L6
Original language | English |
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Pages (from-to) | L6 |
Journal | Astronomy and Astrophysics |
Volume | 604 |
DOIs | |
Publication status | Published - 1 Aug 2017 |
Keywords
- stars: individual: EBLM J0555-57Ab
- binaries: eclipsing
- binaries: spectroscopic
- stars: low-mass
- techniques: spectroscopic
- techniques: photometric