WD B1620-26
Encyclopedia
WD B1620-26 is a white dwarf
star that orbits the pulsar PSR B1620-26
and both correspond with PSR B1620-26 planetary system
. It is located in the Messier 4
globular cluster
. The star is sometimes referred to as PSR B1620-26 B, though some consider this notation confusing as it implies that it is a pulsar
, when it is not. An extrasolar planet
in far orbit, orbits both the white dwarf and the pulsar in a circumbinary orbit. It is referred to as PSR B1620-26 b (or PSR B1620-26 c if the white dwarf is referred to as PSR B1620-26 B).
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
star that orbits the pulsar PSR B1620-26
PSR B1620-26
PSR B1620-26 is a binary star system located at a distance of 3,800 parsecs in the globular cluster of Messier 4 in the constellation of Scorpius. The system is composed of a pulsar and a white dwarf...
and both correspond with PSR B1620-26 planetary system
Planetary system
A planetary system consists of the various non-stellar objects orbiting a star such as planets, dwarf planets , asteroids, meteoroids, comets, and cosmic dust...
. It is located in the Messier 4
Messier 4
Messier 4 or M4 is a globular cluster in the constellation of Scorpius. It was discovered by Philippe Loys de Chéseaux in 1746 and catalogued by Charles Messier in 1764. It was the first globular cluster in which individual stars were resolved.-Visibility:M4 is conspicuous in even the smallest of...
globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
. The star is sometimes referred to as PSR B1620-26 B, though some consider this notation confusing as it implies that it is a pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...
, when it is not. An extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
in far orbit, orbits both the white dwarf and the pulsar in a circumbinary orbit. It is referred to as PSR B1620-26 b (or PSR B1620-26 c if the white dwarf is referred to as PSR B1620-26 B).