Pisces II dwarf galaxy

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Galaxy
Pisces II dwarf galaxy
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AladinLite
Constellation fishes
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 22 h 58 m 31 s
declination + 05 ° 57 ′ 09 ″
Appearance
Morphological type dSph  
Brightness  (visual) 16.3 mag
Angular expansion (2.2 ± 0.2) ′
Physical data
Affiliation Local group  
distance 585,000 ly /
180,000 pc
Absolute brightness −5 likes
history
Discovery date 2010
Catalog names
Pisces II

The Pisces II dwarf galaxy (also briefly Pisces II ) is a lenticular dwarf galaxy in the constellation of Pisces and was in the year 2010 in the screening of the Sloan Digital Sky Survey discovered.

properties

Sizes

The galaxy is approximately 180 k pc from our solar system . As a spheroidal dwarf galaxy, it has an approximately round shape with an aspect ratio of 5: 3 and a half-light radius of only 60 pc.

Luminosity

Pisces II is one of the smallest and faintest satellite galaxies in our Milky Way . The integral luminosity corresponds with the absolute brightness of M V = -5 m about 10,000 times that of the sun . This corresponds roughly to the luminosity of an average globular cluster .

Metallicity

The star population of Pisces II consists mainly of older stars that formed about 10–12 billion years ago. The metallicity of these old stars is correspondingly low with [Fe / H] = −2.3 , which means that Pisces II has about 80 times less heavy elements than our sun .

Individual evidence

  1. ↑ a b c d e f g V. Belokurov, Walker, MG; Evans, NW; Gilmore, G .; Irwin, MJ; Just, D .; Koposov, S .; Mateo, M. et al .: Big Fish, Little Fish: Two New Ultra-Faint Satellites of the Milky Way . In: The Astrophysical Journal . 712: L103, 2010. doi : 10.1088 / 2041-8205 / 712/1 / L103 .
  2. ↑ SIMBAD Astronomical Database . In: Results for Pisces II . Retrieved February 13, 2010.