Pisces I (dwarf galaxy)

Pisces I Dwarf Galaxy[1]
Observation data (J2000 epoch)
Constellation Pisces
Right ascension ~23h 40m 00s[2]
Declination ~ −0.3°[2]
Distance 260 kly (80 kpc)[3]
Type dSph?
Apparent dimensions (V) ~1°[2]
Other designations
Pisces I[1]
See also: Galaxy, List of galaxies

Pisces I or Pisces overdensity is a clump of stars in the Milky Way's halo, which may be a disrupted dwarf spheroidal galaxy.[1] It is situated in the Pisces constellation and was discovered in 2009 by analysis of distribution of RR Lyrae stars in the data obtained by Sloan Digital Sky Survey's data.[3] The galaxy is located at the distance of about 80 kpc from the Sun and moves towards it with a speed of about 75 km/s.[2]

Pisces I is one of the faintest satellites of the Milky Way.[1] Its mass is estimated to be at least 105 Solar masses.[3] However it has a large size of about several degrees (around 1  kpc) and may be in a transitional phase between a gravitationally bound galaxy and completely unbound system.[2] Pisces I is located near the plane, where Magellanic Clouds lie. There may exist a connection between the Magellanic stream and this galaxy.[3]