NGC 5054 is a

spiral galaxy Spiral galaxies form a galaxy morphological classification, class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''

Virgo Virgo may refer to: Arts and entertainment * Virgo (film), a 1970 Egyptian film * Virgo (character), several Marvel Comics characters * Virgo Asmita, a character in the manga ''Saint Seiya: The Lost Canvas'' * ''Virgo'' (album), by Virgo Four, ...

. The galaxy lies about 55 million

light years A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astro ...

away from Earth based on redshift-independent methods, which means, given its apparent dimensions, that NGC 5054 is approximately 85,000 light years across. Based on redshift the galaxy lies about 80 million light years away. It was discovered by

William Herschel Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover ...

on December 31, 1785. It is included in the

Herschel 400 Catalogue The Herschel 400 catalogue is a subset of William Herschel, William Herschel's original ''Catalogue of Nebulae and Clusters of Stars'', selected by Brenda F. Guzman (Branchett), Lydel Guzman, Paul Jones, James Morris, Peggy Taylor and Sara Saey of ...

. It lies about 6 degrees southwest of

Spica Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...

and near the star 53 Virginis.

Characteristics

NGC 5054 cutout HST 7330 99 NIC NIC2 F160W sci

NGC 5054 has a bright nucleus which hosts a nuclear bar making the

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 ...

appear elliptical. The galaxy has three prominent

spiral arm Spiral arms are a defining feature of spiral galaxies. They manifest as spiral-shaped regions of enhanced brightness within the galactic disc. Typically, spiral galaxies exhibit two or more spiral arms. The collective configuration of these arms i ...

s in a grand design pattern. The arms emerge from the inner disk spaced about 120 degrees apart. The arms are loosely wrapped around, with the northern arm appearing more tightly wrapped. The arms can be traced for about half a revolution before fading. Many star forming knots are visible in spiral arms. The largest

HII region An H II region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light year ...

s are about two arcseconds across.Sandage, A., Bedke, J. (1994), ''The Carnegie Atlas of Galaxies. Volume I'', Carnegie Institution of Washington The

star formation Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, sta ...

rate of the galaxy is estimated to be 2.6 per year. In the centre of the galaxy lies a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

, whose mass is estimated to be 10^{6.62 ± 0.36} (1.8 - 9.5 millions) , based on the pitch angle of the spiral arms.

Supernovae

Three

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e have been observed in NGC 5054: * SN 2004ab was discovered on 21 February 2004 by L. A. G. Monard at an apparent magnitude of 14.7 2" west and 11" north from the centre of the galaxy. It was identified as 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 ...

about one week past maximum. The supernova was highly reddened. * SN 2014A was discovered on 1 January 2014 by

Lick Observatory Supernova Search The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton (California), Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The ...

using the

Katzman Automatic Imaging Telescope The Katzman Automatic Imaging Telescope (KAIT) is an automated telescope used in the search for supernovae. The telescope had a first light in 1998, and is a noted robotic telescope. It had first recorded data in August 1996, and was formally ded ...

at an apparent magnitude of 16.4. It was identified as a

Type II supernova A Type II supernova or SNII (plural: ''supernovae'') results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type ...

more than a month past explosion. * SN 2018is was discovered on 20 January 2018 at an apparent red magnitude of 17.9. It was identified as a low-luminosity TypeII-P supernova with an atypically steep decline during the photospheric phase and remarkably narrow emission lines.

Nearby galaxies

NGC 5054 lies at the outskirts of the NGC 5044 Group. The difference in redshift between NGC 5054 and the group is -919 ± 61 km/s. Makarov et al place NGC 5054 in the same cloud with the NGC 5044 Group, however belonging to a different group, the NGC 5054 Group, along with NGC 5037 and some other fainter galaxies. A Magellanic galaxy is seen superimposed on the northern arm of the galaxy, 2.7 arcminutes from the centre. It is possible that the interaction of the two galaxies has resulted in star formation in the dwarf galaxy and could be cause of the peculiar arm morphology of NGC 5054. It is also possible that the peculiar shape is the result of the interaction of the galaxy with the extended halo of the NGC 5044 group.

References

External links

NGC 5054 on SIMBAD
{{DEFAULTSORT:NGC 5054 Unbarred spiral galaxies Virgo (constellation) 5054 UGCA objects -03-34-039 46247 Astronomical objects discovered in 1785 Discoveries by William Herschel