Among the approximately 30 satellites of this object are the relatively young Carina Dwarf Spheroidal, the cannibalised Leo II, and the Canis Major Overdensity, which if verified may be even closer than the Sagittarius Dwarf Elliptical Galaxy, this object's largest satellite.
The possible dark galaxy candidate known as Smith's Cloud is expected to merge with this object in approximately 27 million years, an event which is believed to result in stellar genesis, according to a 2008 paper by Lockman et al. A 2009 study conducted using the Very Long Baseline Array measured a velocity of up to 254 km/s for stars located near this object's outer edge, which has contributed to a 2014 study's estimation of this object's mass at 8.5 x 1011 solar masses. In 2010 the Fermi Gamma-ray Space Telescope detected two spherical lobes of high energy emissions north and south (*) of this object's core, and this object's disc is surrounded by the Monoceros Ring. Among the approximately 30 satellites of this object are the relatively young Carina Dwarf Spheroidal, the cannibalised Leo II, and the Canis Major Overdensity, which if verified may be even closer than the Sagittarius Dwarf Elliptical Galaxy, this object's largest satellite. For 10 points, what is this barred spiral galaxy, the second largest in the Local Group, which is set to collide with Andromeda in approximately 4 billion years?
The possible dark galaxy candidate known as Smith's Cloud is expected to merge with this object in approximately 27 million years, an event which is believed to result in stellar genesis, according to a 2008 paper by Lockman et al.
Milky Way Galaxy 