Canis Major Dwarf Galaxy

The Canis Major Dwarf Galaxy ("CMa dwarf") or Canis Major Overdensity ("CMa overdensity") is a disputed dwarf irregular galaxy in the Local Group. It is in the same part of the sky as the constellation Canis Major.
The supposed small galaxy has a relatively high percentage of red giant stars. Itis thought to have about one billion stars in all.
The Canis Major Dwarf is an irregular galaxy. It may be the closest neighbouring galaxy to us in the Milky Way. It is about 25,000 light-years away from the Solar System, and 52,000 light-years from the Galactic centre. It has a roughly elliptical shape and is thought to contain as many stars as the Sag DEG, the previous contender for closest galaxy to us.
Discussion.
The dwarf was discovered in 2003.
Several studies cast doubts on the true nature of this overdensity. Investigation of the area in 2009 showed only ten RR Lyrae variable stars. This is consistent with the Milky Way's halo and thick disk populations, rather than a separate dwarf spheroidal galaxy.