IC 1101 is a supergiant lenticular galaxy

Lenticular galaxy

A lenticular galaxy is a type of galaxy which is intermediate between an elliptical galaxy and a spiral galaxy in galaxy morphological classification schemes. Lenticular galaxies are disk galaxies which have used up or lost most of their interstellar matter and therefore have very little ongoing...

 at the center of the Abell 2029

Abell 2029

Abell 2029 is a large cluster of galaxies a billion light years away in the constellation Virgo. The central galaxy is perhaps the largest known, with estimates ranging from 5.6 to over 6 million light years across; contrast this with the Milky Way, which is 100,000 light years across...

 galaxy cluster

Galaxy cluster

A galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...

. It is 1.07 billion light years away in the constellation of Serpens

Serpens

Serpens is a constellation of the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations defined by the International Astronomical Union....

 and is classified as a cD class of galaxy

Type-cD galaxy

The type-cD galaxy is a galaxy morphology classification, a subtype of type-D giant elliptical galaxy, and has a large halo of stars. They can be found near the centres of some rich galaxy clusters...

.

Size

The galaxy has a diameter of approximately 6 million light years, which makes it currently (as of 2011) the largest known galaxy in terms of breadth. It is the central galaxy of a massive cluster containing a mass (mostly dark matter

Dark matter

In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

) of roughly 100 trillion Stars. Being more than 50 times the size of the Milky Way and 2000 times as massive, if it were in place of our galaxy, it would swallow up the Large Magellanic Cloud

Large Magellanic Cloud

The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...

, Small Magellanic Cloud

Small Magellanic Cloud

The Small Magellanic Cloud is a dwarf galaxy. It has a diameter of about 7,000 light-years and contains several hundred million stars. It has a total mass of approximately 7 billion times the mass of our Sun....

, Andromeda Galaxy

Andromeda Galaxy

The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years from Earth in the constellation Andromeda. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. Andromeda is the nearest spiral galaxy to the...

, and Triangulum Galaxy

Triangulum Galaxy

The Triangulum Galaxy is a spiral galaxy approximately 3 million light years from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101...

. IC 1101 owes its size to many collisions of much smaller galaxies about the size of the Milky Way and Andromeda galaxies.