Phoenix Dwarf
Encyclopedia
The Phoenix Dwarf is a dwarf galaxy
Dwarf galaxy
A dwarf galaxy is a small galaxy composed of up to several billion stars, a small number compared to our own Milky Way's 200-400 billion stars...

 and an irregular galaxy
Irregular galaxy
An irregular galaxy is a galaxy that does not have a distinct regular shape, like a spiral or an elliptical galaxy. The shape of an irregular galaxy is uncommon – they do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a...

 that was discovered in 1976 by Hans-Emil Schuster
Hans-Emil Schuster
Hans-Emil Schuster is a German astronomer who retired in October 1991. He worked at Hamburg Observatory at Bergedorf and European Southern Observatory , and was former acting director of La Silla Observatory...

 and Richard Martin West
Richard Martin West
Richard Martin West is a Danish astronomer working at the European Southern Observatory .He discovered numerous comets, including the spectacular "Comet West" and the periodic comets 76P/West-Kohoutek-Ikemura and 123P/West-Hartley.He also discovered a number of asteroids, including the Trojan...

 and mistaken for a 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...

. It is currently 1.44 Mly away from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. Its name comes from the fact that it is part of the Phoenix constellation.

Characteristics

The Phoenix dwarf has an inner part of young stars running in an east-west direction and an outer part of mainly old stars that runs north-south. The central region's rate of star formation
Star formation
Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. As a branch of astronomy star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star formation process and the study of young...

 seems to have been relatively constant across time (Martínez-Delgado et al. 1999). In 1999, St-Germain et al. discovered a H I region of about 105 M
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...

 just to the west of Phoenix. Its radial velocity
Radial velocity
Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...

is -23 km/s and may be physically associated with Phoenix if it is found to have a similar radial velocity.
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