spiral galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''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 ...
of Triangulum. It was discovered on November 9, 1876, by French astronomer
. This galaxy is located at a distance of 36 million
light year
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 ...
s 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 596 km/s. 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 this galaxy is Sdm:, indicating it is a spiral (S) with disorganized, irregular
arms
Arms or ARMS may refer to:
*Arm or arms, the upper limbs of the body
Arm, Arms, or ARMS may also refer to:
People
* Ida A. T. Arms (1856–1931), American missionary-educator, temperance leader
Coat of arms or weapons
*Armaments or weapons
**Fi ...
and no central
bulge
__NOTOC__
Bulge may refer to:
Astronomy and geography
*Bulge (astronomy), a tightly packed group of stars at the center of a spiral galaxy
*Equatorial bulge, a bulge around the equator of a planet due to rotation
*Tharsis bulge, vast volcanic pla ...
(dm). The ':' suffix indicates some uncertainty about the classification. It has a visual magnitude of 12.4. The galactic plane is inclined at an angle of 50° to the line of sight from the Earth, giving it an elliptical profile with the major axis aligned along a position angle of 65°. The size of the D25 ellipse (where the brightness of the galaxy drops to magnitude 25) is arcminutes.
When images of NGC 959 are corrected for the effects of
extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
from
dust
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...
, a central
bar
Bar or BAR may refer to:
Food and drink
* Bar (establishment), selling alcoholic beverages
* Candy bar
* Chocolate bar
Science and technology
* Bar (river morphology), a deposit of sediment
* Bar (tropical cyclone), a layer of cloud
* Bar (u ...
feature can be discerned. The galaxy then shows a non-negligible bulge or central condensation, and may instead have a morphological type of SBcd. It displays a cuspy central density profile and bulge-like monotonic decrease in ellipticity toward the core.