Discovery of a Wide Planetary-mass Companion to the Young M3 Star GU Psc
Abstract
We present the discovery of a comoving planetary-mass companion ~42'' (~2000 AU) from a young M3 star, GU Psc, a likely member of the young AB Doradus Moving Group (ABDMG). The companion was first identified via its distinctively red i - z color (>3.5) through a survey made with Gemini-S/GMOS. Follow-up Canada-France-Hawaii Telescope/WIRCam near-infrared (NIR) imaging, Gemini-N/GNIRS NIR spectroscopy and Wide-field Infrared Survey Explorer photometry indicate a spectral type of T3.5 ± 1 and reveal signs of low gravity which we attribute to youth. Keck/Adaptive Optics NIR observations did not resolve the companion as a binary. A comparison with atmosphere models indicates T eff = 1000-1100 K and log g = 4.5-5.0. Based on evolution models, this temperature corresponds to a mass of 9-13 M Jup for the age of ABDMG (70-130 Myr). The relatively well-constrained age of this companion and its very large angular separation to its host star will allow its thorough characterization and will make it a valuable comparison for planetary-mass companions that will be uncovered by forthcoming planet-finder instruments such as Gemini Planet Imager and SPHERE.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2014
- DOI:
- 10.1088/0004-637X/787/1/5
- arXiv:
- arXiv:1405.2932
- Bibcode:
- 2014ApJ...787....5N
- Keywords:
-
- infrared: planetary systems;
- planetary systems;
- planets and satellites: detection;
- stars: imaging;
- stars: individual: GU Psc;
- stars: low-mass;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 18 p., 10 fig., published in ApJ. May 20th, 2014: Small corrections compared to the journal version: 1) addition of the an important reference to 1RSX 1609-2105b from Lafreni\`ere et al. 2008, 2010, 2) update of the url for Andrew Mann metallicity calibration, 3) correction of a few factual mistakes in section 2.2.4), 4) aesthetic reformatting of urls