There are about More than 100 billion galaxies in the observable universe. For roughly 13 billion years they’ve swarmed around each other, colliding and merging, undergoing rapid star formation and suffering periods of drought, where no new stars are born.
They range in size and shape from small, dwarf galaxies to the beautiful and graceful mid-range spiral galaxies to the gigantic and ancient ellipticals. The smallest, the dwarf galaxies, can be as small as 200 light years across and not much more massive than a star cluster.
They contain as few as a hundred million stars and act as shepherds of most of the spiral galaxies we see today. The largest galaxies in the universe are the ellipticals. They are featureless collections of very old stars that range in shape from nearly spherical to highly flat and contains as many as a trillion stars.
IC 1101 is located one billion light years away in the constellation Serpens, this is the largest galaxy in the known universe. It is enormous, it has a diameter of six million light years and a mass of over 100 trillion stars, with most of that mass in the form of elusive dark matter.
Of all the structures we’ve ever seen, this is the most massive in the first 4 billion years of the universe,
astronomer Mark Brodwin said.
IC 1101 is more than 50 times the size of the Milky Way and 2000 times as massive. If it were in put in place of our galaxy, it would swallow up the Large Magellanic Cloud, Small Magellanic Cloud, Andromeda Galaxy, and Triangulum Galaxy.
The galaxy was discovered on 19 June 1790 by the British astronomer Frederick William Herschel I. It was catalogued in 1895 by John Louis Emil Dreyer as the 1,101st object of the Index Catalogue of Nebulae and Star Clusters (IC). At its discovery, it was identified as a nebulous feature. Following Edwin Hubble’s 1932 discovery that some of the “nebulous features” were actually independent galaxies, subsequent analysis of objects in the sky were conducted and IC 1101 was therefore found to be one of the independent galaxies.