The metal-poor composition of its planetary-mass companion could explain its spectral type, as it is theorized that hydrogen-deficient stars of the asymptotic giant branch could evolve into white dwarfs of spectral type DB and then DQ as they cool down.

[5] WD 0806-661 is estimated to be 1.5-2.7 billion years old,[6] and likely used to be an A-type main sequence star of 2.1 ± 0.3 solar masses before reaching the end of its life and becoming a white dwarf.

However, due to the object's high mass, internal heat keeps the temperature hotter than that of Earth.

Despite having temperatures comparable to that of Earth, WD 0806−661 B is a poor candidate for extraterrestrial life due to high surface gravity and lack of starlight.

[9] However, the IAU considers objects below the ~13 MJ limiting mass for deuterium fusion that orbit stars (or stellar remnants), with M2/M1[a] < 1/25 to be planets, no matter how they formed.