Boötes I (dwarf galaxy)

The boat I dwarf galaxy ( also short boat I or Boo I dSph ) is an extremely faint dwarf spheroidal galaxy in the constellation of the Bear Warden and thus belongs to the subtype Ulta faint dwarf galaxies.

Properties

The galaxy has a luminosity of only about 100,000 L ☉ and an absolute magnitude of - 5.8m. It is only about 197 kly away and seems to be deformed and torn apart by tidal forces of the Milky Way. She shows two star tails that intersect. Normally, tidal forces shape only a tail in satellite galaxies.

Like most of the so-called ultra- faint dwarf galaxies is the entire galaxy fainter than the single star Rigel

Remark

Apparent brightness Absolute brightness = distance modulus = -5.8 18.9 = 13.1