Local Group Reference Libraries

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Magellanic Clouds
2010-09-16 15:14:03

The two Magellanic Clouds (or Nubeculae Magellani), composed of the Large Megellanic Cloud and the Small Magellanic Cloud, are irregular dwarf galaxies visible in the southern hemisphere. They are members of our Local Group and orbit the Milky Way galaxy. Persian astronomer Al Sufi, in 964, was the first to have written anything about the Magellanic Clouds proving they have been known since...

The Local Group
2010-09-13 17:05:00

The Local Group, compromising more than 30 galaxies (including dwarf galaxies and the Milky Way), is a group of galaxies with a gravitational center located somewhere between the Milky Way and the Andromeda Galaxy. With a binary (dumbbell) shape and a total mass of (1.29 ± 0.14) × 1012M the Local group covers a 10 million light-year diameter. The local group is part of the Virgo...

IC 342
2010-09-13 16:59:36

The IC 342/Maffei Group (also known as the IC 342 Group or the Maffei 1 Group) is the closest group of galaxies to the Local Group. The member galaxies are both concentrated around the two brightest galaxies of IC 342 and Maffei 1. The group can therefore be described as a binary group. Along with many others the group is located in the Virgo Supercluster.

Ring Galaxy
2004-10-19 04:45:42

Ring Galaxy -- A subclass of interacting galaxies, ring galaxies, provides a unique laboratory for studying unusually large bursts of non-nuclear star formation. The rings in these systems are often large (10s of kiloparsecs) and contain what appear to be associations of giant H{\small II} regions. As a basis for future modeling of star forming regions in observed ring galaxies we...

Irregular Galaxy
2004-10-19 04:45:41

Irregular Galaxy -- In astronomy, a class of galaxy with little structure, which does not conform to any of the standard shapes in the Hubble classification. The two satellite galaxies of the Milky Way, the Magellanic Clouds, are both irregulars. Some galaxies previously classified as irregulars are now known to be normal galaxies distorted by tidal effects or undergoing bursts of star...

Globular Cluster
2004-10-19 04:45:41

Globular Cluster -- A globular cluster is a cluster of stars that is spherical in shape and extremely dense towards its core. Globular clusters are usually composed of hundreds of thousands of old stars, similar to the bulge of a spiral galaxy but confined to a volume of only a few cubic parsecs. Some globular clusters (like Omega Centauri in our Milky Way, and G1 in M31) are truly massive...

2004-10-19 04:45:41

Galaxy -- Stars are almost always found in collections called galaxies, together with gas, dust, and large amounts of dark matter detected by its gravitational effects. These are all held together by gravitational attraction and orbit a common centre. There is some evidence that black holes may exist at the centre of some or most galaxies. Galaxies come in three main types: ellipticals,...

Virgo Cluster of Galaxies
2004-10-19 04:45:40

Virgo Cluster of Galaxies -- This giant agglomeration of galaxies is the nearest big cluster of galaxies, the largest proven structure in our intergalactic neighborhood, and the most remote cosmic objects with a physical connection to our own small group of galaxies, the Local Group, including our Milky Way galaxy. This structure is another discovery by Charles Messier, who noted behind his...

Virgo A Galaxy M87
2004-10-19 04:45:40

Virgo A Galaxy -- Discovered 1781 by Charles Messier. The giant elliptical galaxy M87, also called Virgo A, is one of the most remarkable objects in the sky. It is perhaps the dominant galaxy in the closest big cluster to us, the famous Virgo Cluster of galaxies (sometimes also called "Coma-Virgo cluster" which is more acurate, as it extends into constellation Coma), and lies at the...

Triangulum Galaxy
2004-10-19 04:45:40

Triangulum Galaxy -- The Triangulum Galaxy, Messier object M33, is a spiral galaxy of type Sc located in the constellation Triangulum. Triangulum is small relative to its larger neighbors such as the Milky Way and Andromeda Galaxy, but is about average compared to most spiral galaxies in the universe. Triangulum is a member of the Local Group of galaxies and may be a gravitationally...

Word of the Day
  • A coin originally worth six pennies Scots, and later three; held equivalent to an English halfpenny.
  • (in plural) Money; cash.