See also
| Stars |
| ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||
| Galaxies |
| ||||||||||
| |||||||||||
| |||||||||||
 | This galaxy-related article is a stub. You can help Wikipedia by expanding it. |
| BDF-521 | |
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Piscis Austrinus |
| Right ascension | 22h 27m 46.66s |
| Declination | −35° 07′ 07.7″ |
| Redshift | 7.008 |
| Distance | 12.9 billion light-years (light travel distance) |
| Apparent magnitude (V) | 28 |
| Other designations | |
| CFP2010 BDF 521 | |
BDF-521 is a remote galaxy with a redshift of z = 7.008 corresponds to a distance traveled by light to come down to Earth of 12.89 billion light years.
| Stars |
| ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||
| Galaxies |
| ||||||||||
| |||||||||||
| |||||||||||
| | This galaxy-related article is a stub. You can help Wikipedia by expanding it. |
Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. In Greek mythology, Centaurus represents a centaur; a creature that is half human, half horse. Notable stars include Alpha Centauri, the nearest star system to the Solar System, its neighbour in the sky Beta Centauri, and V766 Centauri, one of the largest stars yet discovered. The constellation also contains Omega Centauri, the brightest globular cluster as visible from Earth and the largest identified in the Milky Way, possibly a remnant of a dwarf galaxy.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The word galaxy is derived from the Greek galaxias (γαλαξίας), literally "milky", a reference to the Milky Way. Galaxies range in size from dwarfs with just a few hundred million stars to giants with one hundred trillion stars, each orbiting its galaxy's center of mass.
In astronomy, an astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms object and body are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial object is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures.
The observable universe is a spherical region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. There may be 2 trillion galaxies in the observable universe, although that number has recently been estimated at only several hundred billion based on new data from New Horizons. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe has a spherical volume centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.
Draco is a constellation in the far northern sky. Its name is Latin for dragon. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations today. The north pole of the ecliptic is in Draco. Draco is circumpolar, and can be seen all year from northern latitudes.
NGC 1, also occasionally referred to as GC 1, UGC 57, PGC 564 or Holm 2a is an intermediate spiral galaxy of the morphological type Sbc, located approximately 210 to 215 million light-years from the Solar System in the constellation Pegasus. It was discovered on 30 September 1861 by Heinrich d'Arrest.
NGC 891 is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus.
The Catalogue of Principal Galaxies (PGC) is an astronomical catalog published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies. It is based on the Lyon-Meudon Extragalactic Database (LEDA), which was originally started in 1983. 40,932 coordinates (56%) have standard deviations smaller than 10″. A total of 131,601 names from the 38 most common sources are listed. Available mean data for each object are given:
The Boötes void is an enormous, approximately spherical region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name. Its center is located at approximately right ascension14h 50m and declination 46°.
NGC 4676, or the Mice Galaxies, are two spiral galaxies in the constellation Coma Berenices. About 290 million light-years away, they began the process of colliding and merging. Their name refers to the long tails produced by tidal action—the relative difference between gravitational pulls on the near and far parts of each galaxy—known here as a galactic tide. It is a possibility that both galaxies, which are members of the Coma cluster, have experienced collision, and will continue colliding until they coalesce.
Andromeda X is a dwarf spheroidal galaxy about 2.9 million light-years away from the Sun in the constellation Andromeda. Discovered in 2005, And X is a satellite galaxy of the Andromeda Galaxy (M31).
XMMXCS 2215-1738 is a galaxy cluster that lies 10 billion light-years away and has a redshift value of z=1.45. It was discovered by the XMM Cluster Survey in 2006.
A1689-zD1 is a galaxy in the Virgo constellation cluster. It was a candidate for the most distant and therefore earliest-observed galaxy discovered as of February 2008, based on a photometric redshift.
NGC 4889 is an E4 supergiant elliptical galaxy. It was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a median distance of 94 million parsecs from Earth. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The gamma ray bursts from the galaxy extend out to several million light years of the cluster.
NGC 4874 is a giant elliptical galaxy. It was discovered by the British astronomer Frederick William Herschel I in 1785, who catalogued it as a bright patch of nebulous feature. The second-brightest galaxy within the northern Coma Cluster, it is located at a distance of 109 megaparsecs from Earth. The galaxy is surrounded by an immense stellar halo that extends up to one million light-years in diameter. It is also enveloped by a huge cloud of interstellar medium that is currently being heated by action of infalling material from its central supermassive black hole. A jet of highly energetic plasma extends out to 1,700 light-years from its center. The galaxy has 18 700 ± 2260 globular clusters.
NGC 54 is an edge-on spiral galaxy in the constellation of Cetus. The galaxy was discovered by Wilhelm Tempel in 1886, and he defined it as "very faint, pretty small, round." The galaxy is 90,000 light years in diameter, making it slightly smaller than the Milky Way.
NGC 128 is a lenticular galaxy in the constellation Pisces. It is approximately 190 million light-years from the Sun and has a diameter of about 165,000 light-years.
NGC 7001 is an intermediate spiral galaxy located about 300 million light-years away in the constellation Aquarius. NGC 7001 has an estimated diameter of 106,000 light-years. It was discovered by English astronomer John Herschel on July 21, 1827 and was also observed by Austrian astronomer Rudolf Spitaler on September 26, 1891.
NGC 681 is an intermediate spiral galaxy in the constellation of Cetus, located approximately 66.5 million light-years from Earth. The name Little Sombrero Galaxy is a reference to a much larger and earlier observed sombrero-like galaxy designated M104, or the Sombrero Galaxy.