WD J1953−1019 is a hierarchical triple system of
white dwarf
A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place i ...
s located at about 130 parsecs (about 420 light years) from the Earth. This is the first triple system of white dwarfs to be resolved.
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
The ''Gaia'' catalogues are star catalogues created using the results obtained by ''Gaia (spacecraft), Gaia'' space telescope.
The catalogues are released in stages that will contain increasing amounts of information; the early releases also mis ...
4190499986125543168
and 4190499986125543296
respectively. The white dwarfs of the central pair, WD J1953−1019 B and C, are separated from each other while the distant companion, WD J1953−1019 A, orbits the
barycenter
In astronomy, the barycenter (or barycentre; ) is the center of mass of two or more bodies that orbit one another and is the point about which the bodies orbit. A barycenter is a dynamical point, not a physical object. It is an important con ...
, or center of mass, of the central binary at a distance of .
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.
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.
However, if this collision occurred, it could produce a
type Ia supernova
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...
below the
Chandrasekhar mass.
See also
*
SDSS J0106−1000 – a short-period binary white dwarf system, in the constellation
Cetus
Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus (mythology), Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water- ...
*
WD J0651+2844 – another short-period binary white dwarf system, in the constellation
Gemini
Gemini most often refers to:
* Gemini (constellation), one of the constellations of the zodiac
* Gemini (astrology), an astrological sign
Gemini may also refer to:
Science and technology Space
* Gemini in Chinese astronomy, the Gemini constellat ...
Notes
References
{{DEFAULTSORT:WD J1953-1019
Triple star systems
White dwarfs
Aquila (constellation)