Pisces Dwarf

This article is about the suspected satellite galaxy of the Triangulum Galaxy. For other dwarf galaxies labelled Pisces, see Pisces (disambiguation).

The Pisces Dwarf, also known as Pisces I,^[1] is an irregular dwarf galaxy that is part of the Local Group. The galaxy, taking its name from the constellation Pisces where it appears, is suspected of being a satellite galaxy of the Triangulum Galaxy (M33). It displays a blueshift, as it is approaching the Milky Way at 287 km/s. It may be transition-type galaxy, somewhere between dwarf spheroidal and dwarf irregular. Alternatively, it may be a rare, but statistically acceptable, version of one of the two types.^[2]

Pisces Dwarf
The Pisces Dwarf in combined UV and visible light
Observation data (J2000 epoch)
Constellation	Pisces
Right ascension	01h 03m 55.0s[1]
Declination	+21° 53′ 06″[1]
Redshift	-287 ± 0 km/s[1]
Distance	2.51 ± 0.08 Mly (769 ± 25 kpc)[2]
Apparent magnitude (V)	14.2[1]
Characteristics
Type	dIrr/dSph[1]
Apparent size (V)	2′ × 2′[1]
Other designations
Pisces I, Psc I, LGS 3,[1] PGC 3792,[1] LEDA 3792

History

It was discovered by Valentina Karachentseva in 1976.^[2][3][4]

Star formation history

Apparently, the star formation rate in the Pisces Dwarf has been declining for the past 10 billion years. Most of the galaxy's stars were formed in its early years, about 8 billion years ago. The study has also shown that there has been no significant star formation for the past 100 million years. Hence, most of the stars that populate this galaxy are old, metal-rich stars aged about 2.5 billion years. However, there are small clusters of young, hot, blue stars on the outer areas of the galaxy.^[5]