spiral galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Perseus
In Greek mythology, Perseus (Help:IPA/English, /ˈpɜːrsiəs, -sjuːs/; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus ...
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
. It is located at a distance of about 36 million
light years
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
from the
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...
and is receding with a heliocentric
radial velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...
of . This galaxy was discovered by the Anglo-German astronomer
William Herschel
Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline H ...
on October 6, 1784, who described it as "pretty faint, large, extended 90°±, much brighter middle, mottled but not resolved". It is a member of the
NGC 1023 group
The NGC 1023 group is a group of galaxies about 20.6 million light-years away from Earth. It is a group in the Local Supercluster along with the Local Group.
Members
* Probable (dwarfs): DDO 024, DDO 025.
* Possible members: NGC 672, IC 1 ...
of galaxies.
The morphological class of NGC 1003 is SAcd, which means it is an unbarred spiral galaxy (SA) with somewhat loosely-wound
spiral arm
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''position angle
In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the north celestial pole (NCP), turning positive into the d ...
of 276°. The visual disk of the galaxy shows a substantial warping in the eastern side, turning it almost face on. The estimated
virial mass
In astrophysics, the virial mass is the mass of a gravitationally bound astrophysical system, assuming the virial theorem applies. In the context of galaxy formation and dark matter halos, the virial mass is defined as the mass enclosed within th ...
of and a mass-to-light ratio of 0.7.
A
type Ia supernova
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...
was discovered in the galaxy by F. Zwicky in 1937, and subsequently designated SN 1937D.
Gallery
File:Deep_Dive_into_a_Galaxy_Cluster.jpg, NGC 1003 taken from the
Nicholas U. Mayall Telescope
The Nicholas U. Mayall Telescope, also known as the Mayall 4-meter Telescope, is a four-meter (158 inches) reflector telescope located at the Kitt Peak National Observatory in Arizona and named after Nicholas U. Mayall. It saw first light on F ...
at
Kitt Peak National Observatory
The Kitt Peak National Observatory (KPNO) is a United States astronomy, astronomical observatory located on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono Oʼodham Nation, west-southwest of Tucson, Arizona. With ...