WD 0806−661 B

WD 0806−661 b / Ahra
JWST image of WD 0806−661 B and its white dwarf star
Discovery
Discovered byLuhman et al.
Discovery date2011
Direct imaging
Designations
Ahra, GJ 3483 B
Orbital characteristics
2,500 AU
StarWD 0806−661
Physical characteristics
1.08±0.02 RJ
Mass8±MJ
4.26±0.08 cgs
Temperature346±4 K
Atmosphere
Composition by volumeH2, He dominated, detected: H2O, NH3, CH4 CO, CO2, H2S

WD 0806−661 B or b, formally named Ahra, is a planetary-mass companion of the white dwarf star WD 0806−661, or Maru.

This object was discovered in 2011 by the Spitzer Space Telescope. It has a mass of between 7–9 MJ, putting it as a gas giant planet. At the time of its discovery, WD 0806−661 b was the coldest brown dwarf ever discovered, with a temperature in the range 325–350 Kelvin (52–77 °C or 125–170 °F) and also had the largest separation from its star at about 2,500 AU at the time of its discovery. The photometric colors of the object suggest it is metal-poor.