Boötes I (dwarf galaxy)
The Boötes Dwarf Galaxy ("Boo I dSph") is a galaxy, which appears faint, with a luminosity of and an absolute magnitude of –5.8. It lies about away in the constellation Boötes. This dwarf spheroidal galaxy appears to be tidally disrupted by the Milky Way Galaxy, which it orbits, and has two stellar tails that cross over to form a cross. Tidally disrupted galaxies usually only form one tail. Like many of the ultrafaint dwarf spheroidals, the entire galaxy appears fainter than the Rigel system (absolute magnitude –7.84). Even so, it is one of the more luminous  UFDs. It is metal-poor, like other UFDs, with a mean metallicity of −2.34. The stellar population of Boötes I is mostly very old stars. The two populations have essentially the same age, 13.4 billion and 13.3 billion years, respectively, with most of the stars being of the latter population.