Pegasus Dwarf Irregular Galaxy
Encyclopedia
The Pegasus Dwarf Irregular Galaxy (also known as Peg DIG or the Pegasus Dwarf) is an irregular galaxy
and a dwarf galaxy
in the direction of the constellation
Pegasus
. It was discovered by A.G. Wilson in the 1950s. The Pegasus Dwarf is a companion of the Andromeda Galaxy
in the Local Group
.
and the related distance estimate has been subject to discussions in the scientific literature, with varying results, however, recently, by use of the tip of the red giant branch, a distance within 10% error was achieved in 2000
and then improved to 3% in 2005.
television series Stargate: Atlantis. While it's mentioned the show takes place in "the Pegasus galaxy" it has not explicitly stated if it is the Irregular or Spheroidal
. However, when the Pegasus galaxy has been seen from the Midway station an irregular galaxy is shown. Also, in the discussion regarding the new McKay-Carter Intergalactic Gate Bridge, General Hank Landry states that the distance between the Pegasus and Milky Way galaxies is "three million light-years," suggesting that the series takes place in the Pegasus Dwarf Irregular Galaxy.
It is also stated in the pilot by Daniel Jackson that the pegasus galaxy is a dwarf galaxy in the local group, much like the real Pegasus Dwarf Irregular Galaxy.
Irregular galaxy
An irregular galaxy is a galaxy that does not have a distinct regular shape, like a spiral or an elliptical galaxy. The shape of an irregular galaxy is uncommon – they do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a...
and a dwarf galaxy
Dwarf galaxy
A dwarf galaxy is a small galaxy composed of up to several billion stars, a small number compared to our own Milky Way's 200-400 billion stars...
in the direction of the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Pegasus
Pegasus (constellation)
Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:...
. It was discovered by A.G. Wilson in the 1950s. The Pegasus Dwarf is a companion of the 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...
in the Local Group
Local Group
The Local Group is the group of galaxies that includes Earth's galaxy, the Milky Way. The group comprises more than 30 galaxies , with its gravitational center located somewhere between the Milky Way and the Andromeda Galaxy...
.
General information
In 1975 Tully & Fisher determined that it was part of the Local Group. The metallicityMetallicity
In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...
and the related distance estimate has been subject to discussions in the scientific literature, with varying results, however, recently, by use of the tip of the red giant branch, a distance within 10% error was achieved in 2000
and then improved to 3% in 2005.
In popular culture
This galaxy is presumed to be the primary location of the science fictionScience fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
television series Stargate: Atlantis. While it's mentioned the show takes place in "the Pegasus galaxy" it has not explicitly stated if it is the Irregular or Spheroidal
Pegasus Dwarf Spheroidal Galaxy
The Pegasus Dwarf Spheroidal is a dwarf spheroidal galaxy about 2.7 million light-years away in the constellation Pegasus...
. However, when the Pegasus galaxy has been seen from the Midway station an irregular galaxy is shown. Also, in the discussion regarding the new McKay-Carter Intergalactic Gate Bridge, General Hank Landry states that the distance between the Pegasus and Milky Way galaxies is "three million light-years," suggesting that the series takes place in the Pegasus Dwarf Irregular Galaxy.
It is also stated in the pilot by Daniel Jackson that the pegasus galaxy is a dwarf galaxy in the local group, much like the real Pegasus Dwarf Irregular Galaxy.
See also
- Pegasus Dwarf Spheroidal GalaxyPegasus Dwarf Spheroidal GalaxyThe Pegasus Dwarf Spheroidal is a dwarf spheroidal galaxy about 2.7 million light-years away in the constellation Pegasus...
(Peg dSph) - Pegasus galaxy, the Stargate AtlantisStargate AtlantisStargate Atlantis is a Canadian-American adventure and military science fiction television series and part of MGM's Stargate franchise. The show was created by Brad Wright and Robert C. Cooper as a spin-off series of Stargate SG-1, which was created by Wright and Jonathan Glassner and was itself...
fictional location.