A satellite galaxy is a smaller companion galaxy that travels on bound orbits within the gravitational potential of a more massive and luminous host galaxy. Satellite galaxies and their constituents are bound to their host galaxy, in the same way that planets within our own solar system are gravitationally bound to the Sun. While most satellite galaxies are dwarf galaxies, satellite galaxies of large galaxy clusters can be much more massive. The Milky Way is orbited by about fifty satellite galaxies, the largest of which is the Large Magellanic Cloud.
The Large Magellanic Cloud, the Milky Way's largest satellite galaxy, and fourth largest in the Local Group. This satellite is also classified as a transition type between a dwarf spiral and dwarf irregular.
Remnants of a minor merger can be observed in the form of a stellar stream falling onto the galaxy NGC 5907.
An edge-on photo of the Needle Galaxy (NGC 4565) that demonstrates the observed thick disk and thin disk components of satellite galaxies.
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about 9.86 kiloparsecs (32,200 light-years) across. It is roughly one-hundredth the mass of the Milky Way and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).
Small part of the Large Magellanic Cloud
ESO's VISTA image of the LMC
Two very different glowing gas clouds in the Large Magellanic Cloud, NGC 2014 (red) and NGC 2020 (blue)
NGC 1783 is one of the biggest globular clusters in the Large Magellanic Cloud