NGC 891
Encyclopedia
NGC 891 is an edge-on unbarred spiral galaxy
about 30 million
light-year
s 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 object is visible in small to moderate size telescope
s as a faint elongated smear of light with a dust lane
visible in larger apertures.
In 1999, the Hubble Space Telescope
imaged NGC 891 in infrared
.
In 2005, due to its attractiveness and scientific interest, NGC 891 was selected to be the first light image of the Large Binocular Telescope
.
Supernova
SN 1986J was discovered on August 21, 1986 at apparent magnitude 14.
of the galaxy, away from its galactic disk. Scientists presume that supernova explosions caused this interstellar dust to be thrown out of the galactic disk toward the halo.
It may also be possible that the light pressure from surrounding stars causes this phenomenon.
Investigations done by Gilbert A. Esquerdo and John C. Barentine in infrared give rise to suspects that it has the Hubble type SBb with a bar. This bar, if it exists, cannot be seen in the visible image, as it is edge-on from our perspective. The bar hypothesis is also supported by the fact that billions of stars orbiting the center appear to be moving too fast.
The galaxy is a member of a small group of galaxies, sometimes called the NGC 1023 group
. Other galaxies in this group are the NGCs 925
, 949, 959, 1003, 1023, and 1058
, and the UGCs 1807, 1865 (DDO 19), 2014 (DDO 22), 2023 (DDO 25), 2034 (DDO 24), and 2259. The outskirts with low surface brightness are populated by multiple, coherent, and vast substructures, like giant streams that loop around the parent galaxy up to distances of approximately 50 kpc. The bulge and the disk are surrounded by a flat and thick cocoon-like stellar structure. These have vertical and radial distances of up to 15 kpc and 40 kpc, respectively.
by John Carpenter
features an instrumental piece called When Twilight Falls On NGC 891.
The first solo album by Edgar Froese
, Aqua, contained a track called "NGC 891".
Unbarred spiral galaxy
An unbarred spiral galaxy is a type of spiral galaxy without a central bar, or one that is not a barred spiral galaxy. It is designated with an SA in the galaxy morphological classification scheme.The Sombrero Galaxy is an unbarred spiral galaxy....
about 30 million
1 E23 m
To help compare different orders of magnitude, this page lists distances starting at 100 Zm .Distances shorter than 100 Zm* 140 Zm — 15 million light years — Distance to Centaurus A galaxy...
light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in 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....
Andromeda
Andromeda (constellation)
Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...
. It was discovered by William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
on October 6 1784. The galaxy is a member of the NGC 1023 group of galaxies
NGC 1023 Group
The NGC 1023 group is a group of galaxies about 20.6 million light-years away from Earth. The group resides in the Canes Venatici Cloud in the Virgo Supercluster.-Members:* Probable : DDO 024, DDO 025....
in the Local Supercluster. It has an H II nucleus.
The object is visible in small to moderate size telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s as a faint elongated smear of light with a dust lane
Dust lane
A dust lane is a relatively dense obscuring band of interstellar dust, observed as a dark swath against the background of a brighter object, especially a galaxy.-See also:* Interplanetary medium - interplanetary dust...
visible in larger apertures.
In 1999, the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
imaged NGC 891 in infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
.
In 2005, due to its attractiveness and scientific interest, NGC 891 was selected to be the first light image of the Large Binocular Telescope
Large Binocular Telescope
Large Binocular Telescope is an optical telescope for astronomy located on Mount Graham in the Pinaleno Mountains of southeastern Arizona, and is a part of the Mount Graham International Observatory...
.
Supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
SN 1986J was discovered on August 21, 1986 at apparent magnitude 14.
Peculiarities
Although this galaxy looks as we think our own galaxy would look like when viewed edge-on, recent high-resolution images of its dusty disk show unusual filamentary. These patterns are extending into the haloGalactic halo
The term galactic halo is used to denote an extended, roughly spherical component of a galaxy, which extends beyond the main, visible component. It can refer to any of several distinct components which share these properties:* the galactic spheroid...
of the galaxy, away from its galactic disk. Scientists presume that supernova explosions caused this interstellar dust to be thrown out of the galactic disk toward the halo.
It may also be possible that the light pressure from surrounding stars causes this phenomenon.
The galaxy is a member of a small group of galaxies, sometimes called the NGC 1023 group
NGC 1023 Group
The NGC 1023 group is a group of galaxies about 20.6 million light-years away from Earth. The group resides in the Canes Venatici Cloud in the Virgo Supercluster.-Members:* Probable : DDO 024, DDO 025....
. Other galaxies in this group are the NGCs 925
NGC 925
NGC 925 is a barred spiral galaxy in the constellation Triangulum, about 45 million light-years away.- References :...
, 949, 959, 1003, 1023, and 1058
NGC 1058
NGC 1058 is a Seyfert Type 2 galaxy in the Perseus constellation. It is approximately 27.4 million light years from Earth and has an apparent magnitude of 11.82. It is receding from Earth at , and at relative to our Galaxy....
, and the UGCs 1807, 1865 (DDO 19), 2014 (DDO 22), 2023 (DDO 25), 2034 (DDO 24), and 2259. The outskirts with low surface brightness are populated by multiple, coherent, and vast substructures, like giant streams that loop around the parent galaxy up to distances of approximately 50 kpc. The bulge and the disk are surrounded by a flat and thick cocoon-like stellar structure. These have vertical and radial distances of up to 15 kpc and 40 kpc, respectively.
In popular culture
The soundtrack of the 1974 film Dark StarDark Star (film)
Dark Star is a 1974 American comedic science fiction motion picture directed by John Carpenter and co-written with Dan O'Bannon.-Backstory and plot:...
by John Carpenter
John Carpenter
John Howard Carpenter is an American film director, screenwriter, producer, editor, composer, and occasional actor. Although Carpenter has worked in numerous film genres in his four-decade career, his name is most commonly associated with horror and science fiction.- Early life :Carpenter was born...
features an instrumental piece called When Twilight Falls On NGC 891.
The first solo album by Edgar Froese
Edgar Froese
Edgar Wilmar Froese is a German artist and electronic music pioneer, best known for founding the electronic music group, Tangerine Dream. Although his solo and group recordings prior to 2003 name him as "Edgar Froese", his solo albums from 2003 onward bear the artist name "Edgar W. Froese".Froese...
, Aqua, contained a track called "NGC 891".