Pisces II (dwarf galaxy)
Encyclopedia
Pisces II is a dwarf spheroidal galaxy
situated in the Pisces constellation and discovered in 2010 in the data obtained by Sloan Digital Sky Survey
. The galaxy is located at the distance of about 180 kpc from the Sun. It is classified as a dwarf spheroidal galaxy
(dSph) meaning that it has an elongated shape with the half-light radius of about 60 pc and ratio of the axis of about 5:3.
Pisces II is one of the smallest and faintest satellites of the Milky Way
—its integrated luminosity is about 10,000 times that of the Sun (absolute magnitude
of about −5), which corresponds to the luminosity of an average globular cluster
. The stellar population of Pisces II consists mainly of moderately old stars formed 10–12 billion years ago. The metallicity of these old stars is low at , which means that they contain at least 80 times less heavy elements than the Sun.
Dwarf spheroidal galaxy
Dwarf spheroidal galaxy is a term in astronomy applied to low luminosity galaxies that are companions to the Milky Way and to the similar systems that are companions to the Andromeda Galaxy M31...
situated in the Pisces constellation and discovered in 2010 in the data obtained by Sloan Digital Sky Survey
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project was named after the Alfred P...
. The galaxy is located at the distance of about 180 kpc from the Sun. It is classified as a dwarf spheroidal galaxy
Dwarf spheroidal galaxy
Dwarf spheroidal galaxy is a term in astronomy applied to low luminosity galaxies that are companions to the Milky Way and to the similar systems that are companions to the Andromeda Galaxy M31...
(dSph) meaning that it has an elongated shape with the half-light radius of about 60 pc and ratio of the axis of about 5:3.
Pisces II is one of the smallest and faintest satellites of the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
—its integrated luminosity is about 10,000 times that of the Sun (absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
of about −5), which corresponds to the luminosity of an average 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 stellar population of Pisces II consists mainly of moderately old stars formed 10–12 billion years ago. The metallicity of these old stars is low at , which means that they contain at least 80 times less heavy elements than the Sun.