WD J1953−1019 is a hierarchical triple system of white dwarfs located at about 130 parsecs (about 420 light years) from the Earth. This is the first triple system of white dwarfs to be resolved.[3][1] The three white dwarfs have an atmosphere of pure hydrogen and a mass of about 0.6 times that of the Sun.
The system consists of a central pair, WD J1953−1019 BC, and a distant companion, WD J1953−1019 A. WD J1953−1019 B and C correspond to the sources Gaia DR2 4190499986125543168[4] and 4190499986125543296[5] respectively. The white dwarfs of the central pair, WD J1953−1019 B and C, are separated 303.25±0.01 AU from each other while the distant companion, WD J1953−1019 A, orbits the barycenter, or center of mass, of the central binary at a distance of 6398.97±0.09 AU.[1]
The cooling age found by M. Perpinyà-Vallès and collaborators for the three white dwarfs is consistent, with an estimated value between 40 and 290 million years.[1] The three stars would each come from a star that had a mass between 1.6 and 2.6 times that of the Sun. A collision of the central pair due to Lidov-Kozai oscillations is unlikely as the system is dynamically stable.[1] However, if this collision occurred, it could produce a type Ia supernova below the Chandrasekhar mass.[1]
See also
SDSS J0106−1000 – a short-period binary white dwarf system, in the constellation Cetus
WD J0651+2844 – another short-period binary white dwarf system, in the constellation Gemini
Notes
^The color composite consists of Pan-STARRS images taken in g, i, and ypassband filters.[1] These filters correspond to specific wavelengths of 481 nm, 752 nm, and 962 nm, respectively.[2]
