[en] 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 M[SUB]Jup[/SUB] (0.081 M[SUB]⊙[/SUB]) and a radius of 0.84[SUP]+ 0.14[/SUP][SUB]-0.04[/SUB]R[SUB]Jup[/SUB] (0.084 R[SUB]⊙[/SUB]) that is comparable to that of Saturn. EBLM J0555-57Ab has a surface gravity log g[SUB]2[/SUB] =5.50[SUP]+ 0.03[/SUP][SUB]-0.13[/SUB] 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 <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/L6">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/L6</A>
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
von Boetticher, Alexander; Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE, UK ; Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK
Triaud, Amaury H. M. J.; Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK
Queloz, Didier; Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE, UK ; Observatoire Astronomique de l'Université de Genève, Chemin des Maillettes 51, 1290, Sauverny, Switzerland
Gill, Samuel; Astrophysics Group, Keele University, Staffordshire, ST55, BG, UK
Lendl, Monika; Space Research Institute, Austrian Academy of Sciences, Schmiedlstr. 6, 8042, Graz, Austria ; Max Planck Institute for Astronomy, Königstuhl 17, 69117, Heidelberg, Germany
Delrez, Laetitia ; Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE, UK ; Université de Liège, Allée du 6 août 17, Sart Tilman, 4000, Liège 1, Belgium
Anderson, David R.; Astrophysics Group, Keele University, Staffordshire, ST55, BG, UK
Collier Cameron, Andrew; SUPA, School of Physics & Astronomy, University of St Andrews, North Haugh, KY16 9SS, St Andrews, Fife, UK
Faedi, Francesca; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
Gillon, Michaël ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Gómez Maqueo Chew, Yilen; Instituto de Astronomía, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, Ciudad de México, México
Hebb, Leslie; Hobart and William Smith Colleges, Department of Physics, Geneva, NY, 14456, USA
Hellier, Coel; Astrophysics Group, Keele University, Staffordshire, ST55, BG, UK
Jehin, Emmanuel ; Université de Liège > Département d'astrophys., géophysique et océanographie (AGO) > Origines Cosmologiques et Astrophysiques (OrCa)
Maxted, Pierre F. L.; Astrophysics Group, Keele University, Staffordshire, ST55, BG, UK
Martin, David V.; Observatoire Astronomique de l'Université de Genève, Chemin des Maillettes 51, 1290, Sauverny, Switzerland
Pepe, Francesco; Observatoire Astronomique de l'Université de Genève, Chemin des Maillettes 51, 1290, Sauverny, Switzerland
Pollacco, Don; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
Ségransan, Damien; Observatoire Astronomique de l'Université de Genève, Chemin des Maillettes 51, 1290, Sauverny, Switzerland
Smalley, Barry; Astrophysics Group, Keele University, Staffordshire, ST55, BG, UK
Udry, Stéphane; Observatoire Astronomique de l'Université de Genève, Chemin des Maillettes 51, 1290, Sauverny, Switzerland
West, Richard; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK)
