SIMP J013656.5+093347 Is Likely a Planetary-mass Object in the Carina-Near Moving Group
Abstract
We report on the discovery that the nearby (∼6 pc) photometrically variable T2.5 dwarf SIMP J013656.5+093347 is a likely member of the ∼200 Myr old Carina-Near moving group with a probability of >99.9% based on its full kinematics. Our v\sin I measurement of 50.9 ± 0.8 km s-1 combined with the known rotation period inferred from variability measurements provide a lower limit of 1.01 ± 0.02 {R}{Jup} on the radius of SIMP 0136+0933, an independent verification that it must be younger than ∼950 Myr, according to evolution models. We estimate a field interloper probability of 0.2% based on the density of field T0-T5 dwarfs. At the age of Carina-Near, SIMP 0136+0933 has an estimated mass of 12.7 ± 1.0 {M}{Jup} and is predicted to have burned roughly half of its original deuterium. SIMP 0136+0933 is the closest known young moving group member to the Sun and is one of only a few known young T dwarfs, making it an important benchmark for understanding the atmospheres of young planetary-mass objects.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2017
- DOI:
- arXiv:
- arXiv:1705.01625
- Bibcode:
- 2017ApJ...841L...1G
- Keywords:
-
- brown dwarfs;
- planets and satellites: atmospheres;
- stars: individual: SIMP J013656.5+093347;
- stars: kinematics and dynamics;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 10 pages, 4 figures, 2 tables. Accepted for publication in the Astrophysical Journal Letters
