8-12 juin, 2014


Discovery of a planetary-mass companion to a young M3 star

Marie-Eve Naud (Université de Montréal)

René Doyon, Étienne Artigau, Lison Malo, Loic Albert, David Lafrenière, Jonathan Gagné, Université de Montréal

A Gemini-S/GMOS survey of nearby young (<150 Myr) stars with deep i+z-band imaging recently allowed the detection of a comoving T3.5 planetary-mass companion. It is located 42’’ (2000 AU) from a M3 that is a highly probable member of the moving group AB Doradus (ABDMG). We performed a detailed characterization of this object through CFHT/WIRCam near-infrared (NIR) and WISE photometry as well as Gemini-N/GNIRS NIR spectroscopy and Keck/AO observations. Atmosphere models comparison point toward a Teff = 1000 – 1100 K and log g = 4.5 – 5.0. Based on evolution models, the companion has a mass of 9 - 13 MJup at the age of ABDMG (70 – 130 Myr). The large angular separation between the companion and its host will allow its thorough spectroscopic characterization without the aid of adaptive optics. With its well-constrained age, this planetary-mass companion will thus make a valuable comparison for the ones that will be uncovered by planet-finder instruments such as GPI and SPHERE.
(doit être confirmé par le SOC)