NGC 4861

Last updated

Coordinates: Jupiter and moon.png 12h 59m 02.340s, +34° 51′ 33.98″

NGC 4861
NGC 4861 - HST- Potw1704a.tif
Hubble Space Telescope image of NGC 4861, taken using the Advanced Camera for Surveys
Observation data (J2000 epoch)
Constellation Canes Venatici
Right ascension 12h 59m 02.340s [1]
Declination +34° 51′ 33.98″ [1]
Redshift 0.002785 [2]
Helio radial velocity 835 [2]
Distance 34.77 ± 15.99  Mly (10.662 ± 4.903  Mpc) [2]
Group or cluster Virgo Cluster
Apparent magnitude  (V)12.32
Apparent magnitude  (B)12.90
Characteristics
Type SB(s)m [2]
Im/BCD
Apparent size  (V)0.797′ × 0.692′ [1]
Other designations
Arp 266, UGC 8098, MCG+06-29-003, PGC 44536 [3]

NGC 4861, also known as Arp 266, is a galaxy in the constellation Canes Venatici. It was discovered by William Herschel on May 1, 1785. [4]

Contents

Morphological classification of NGC 4861 has proved relatively difficult. Its mass, size, and rotational velocity are consistent with it being a spiral galaxy. However, due to its highly irregular shape, it may also be classified as a dwarf irregular galaxy. [5] In fact, since dwarf galaxies are less massive and have lower gravitational potentials, gases and other material for star formation can move within them much faster, causing the galaxy to become a specific type of starburst galaxy, called a blue compact dwarf galaxy. [5] [3] It has also been described as a "comet-like" galaxy due to its resemblance to a comet. [6]

Two ultraluminous X-ray sources (ULXs) have been found within NGC 4861. The first, NGC 4861 X1, is associated with a dense H II region. The second, NGC 4861 X2, seems to be within a small star cluster near the "comet head" of NGC 4861. Assuming it is a star cluster, it has a mass of 400±80  M☉ and an age of 5 million years. Compared to other star clusters with which ULXs are associated, its mass is quite low. [6]

See also

Related Research Articles

Local Group Group of galaxies that includes the Milky Way

The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1022 metres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kpc (3×10^6 ly; 2×1022 m) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.

Messier 49 Elliptical galaxy in the constellation Virgo

Messier 49 is a giant elliptical galaxy about 56 million light-years away in the equatorial constellation of Virgo. This galaxy was discovered by astronomer Charles Messier in 1777.

Messier 59 Elliptical galaxy in the constellation Virgo

Messier 59 or M59, also known as NGC 4621, is an elliptical galaxy in the equatorial constellation of Virgo. It is a member of the Virgo Cluster, with the nearest fellow member 8′ away and around 5 magnitudes fainter. The nearest cluster member of comparable brightness is the lenticular galaxy NGC 4638, which is around 17′ away. It and the angularly nearby elliptical galaxy Messier 60 were both discovered by Johann Gottfried Koehler in April 1779 when observing comet seeming close by. Charles Messier listed both in the Messier Catalogue about three days after Koehler's discovery.

Messier 60 Elliptical galaxy in the constellation Virgo

Messier 60 or M60, also known as NGC 4649, is an elliptical galaxy approximately 57 million light-years away in the equatorial constellation of Virgo. Together with NGC 4647, it forms a pair known as Arp 116. Messier 60 and nearby elliptical galaxy Messier 59 were discovered by Johann Gottfried Koehler in April 1779, observing a comet in the same part of the sky. Charles Messier added both to his catalogue about three days after this.

Dwarf galaxy Small galaxy composed of up to several billion stars

A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies. Astronomers identify numerous types of dwarf galaxies, based on their shape and composition.

Messier 99 Grand design spiral galaxy in the constellation Coma Berenices

Messier 99 or M99, also known as NGC 4254, is a grand design spiral galaxy in the northern constellation Coma Berenices approximately 15,000,000 parsecs from the Milky Way. It was discovered by Pierre Méchain on 17 March 1781. The discovery was then reported to Charles Messier, who included the object in the Messier Catalogue of comet-like objects. It was one of the first galaxies in which a spiral pattern was seen. This pattern was first identified by Lord Rosse in the spring of 1846.

Messier 105 Elliptical galaxy in the constellation Leo

Messier 105 or M105, also known as NGC 3379, is an elliptical galaxy 36.6 million light-years away in the equatorial constellation of Leo. It's the biggest elliptical galaxy in the Messier catalogue that is not in the Virgo cluster. It was discovered by Pierre Méchain in 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96. This galaxy is one of a few not object-verified by Messier so omitted in the editions of his Catalogue of his era. It was appended when Helen S. Hogg found a letter by Méchain locating and describing this object which matched those aspects under its first-published name, NGC 3379.

NGC 1705 Peculiar lenticular galaxy in the constellation Pictor

NGC 1705 is a peculiar lenticular galaxy and a blue compact dwarf galaxy (BCD) in the southern constellation of Pictor, positioned less than a degree to the east of Iota Pictoris, and is undergoing a starburst. With an apparent visual magnitude of 12.6 it requires a telescope to observe. It is estimated to be approximately 17 million light-years from the Earth, and is a member of the Dorado Group.

NGC 4526 Lenticular galaxy in the constellation Virgo

NGC 4526 is a spiral galaxy located approximately 55 million light-years from the Solar System in the Virgo constellation and discovered on 13 April 1784 by William Herschel.

A super star cluster (SSC) is a very massive young open cluster that is thought to be the precursor of a globular cluster. These clusters are referred to as "super" due to the fact that they are relatively more luminous and contain more mass than other young star clusters. The SSC, however, does not have to physically be larger than other clusters of lower mass and luminosity. They typically contain a very large number of young, massive stars that ionize a surrounding HII region or a so-called "Ultra dense HII regions (UDHIIs)" in the Milky Way Galaxy as well as in other galaxies. An SSC's HII region is in turn surrounded by a cocoon of dust. In many cases, the stars and the HII regions will be invisible to observations in certain wavelengths of light, such as the visible spectrum, due to high levels of extinction. As a result, the youngest SSCs are best observed and photographed in radio and infrared. SSCs, such as Westerlund 1 (Wd1), have been found in the Milky Way Galaxy. However, most have been observed in farther regions of the universe. In the galaxy M82 alone, 197 young SSCs have been observed and identified using the Hubble Space Telescope.

NGC 4449 Irregular magellanic type galaxy in the constellation Canes Venatici

NGC 4449, also known as Caldwell 21, is an irregular Magellanic type galaxy in the constellation Canes Venatici, being located about 13 million light-years away. It is part of the M94 Group or Canes Venatici I Group that is relatively close to the Local Group hosting our Milky Way galaxy.

NGC 4323 Lenticular galaxy in the constellation Coma Berenices

NGC 4323 is a lenticular or dwarf elliptical galaxy located about 52.5 million light-years away in the constellation Coma Berenices. The galaxy was discovered in 1882 by astronomer Wilhelm Tempel and is a member of the Virgo Cluster.

NGC 584 Elliptical galaxy in the constellation Cetus

NGC 584 is an elliptical galaxy in the constellation Cetus. The galaxy was discovered on 10 September 1785 by the German-British astronomer William Herschel.

NGC 922 Peculiar galaxy in the constellation Fornax

NGC 922 is a peculiar galaxy in the southern constellation of Fornax, located at a distance of 142 Mly from the Milky Way. It is one of the nearest known collisional galaxies. This object was described by the Herschels as "considerably faint, pretty large, round, gradually pretty much brighter middle." The general form is described by the morphological classification of SB(s)cd pec, which indicates a peculiar (pec) barred spiral galaxy (SB) with no inner ring system around the bar (s) and loosely-wound spiral arms (cd).

NGC 5204 Spiral galaxy in the constellation Ursa Major

NCG 5204 is a Magellanic spiral galaxy located about 14.5 million light-years away from Earth in the constellation of Ursa Major and is a member of the M101 Group of galaxies. It has a galaxy morphological classification of SA(s)m and is highly irregular, with only the barest indication of any spiral arm structure. The galaxy's most prominent feature is an extremely powerful X-ray source designated NGC 5204 X-1. This has resulted in the galaxy being the target of several studies due to the strength of the source and its relative proximity to Earth.

NGC 4402 Spiral galaxy in the constellation Virgo

NGC 4402 is a relatively near, edge-on spiral galaxy located around 50 million light-years from Earth. It is in the constellation of Virgo within the Virgo Cluster of galaxies. It can be seen when viewing Markarian's Chain.

NGC 1222 Lenticular galaxy in the constellation Eridanus

NGC 1222 is an early-type lenticular galaxy located in the constellation of Eridanus. The galaxy was discovered on 5 December 1883 by the French astronomer Édouard Stephan. John Louis Emil Dreyer, the compiler of the New General Catalogue, described it as a "pretty faint, small, round nebula" and noted the presence of a "very faint star" superposed on the galaxy.

NGC 5264 Irregular galaxy in the M83 group of galaxies

NGC 5264, also known as DDO 242, is an irregular galaxy in the constellation Hydra. It is part of the M83 subgroup of the Centaurus A/M83 Group, located some 15 million light years away. The galaxy was discovered on 30 March 1835 by John Herschel, and it was described as "very faint, pretty large, round, very little brighter middle" by John Louis Emil Dreyer, the compiler of the New General Catalogue.

NGC 3921 Interacting galaxy in the constellation Ursa Major

NGC 3921 is an interacting galaxy in the northern constellation of Ursa Major. Estimates using redshift put it at about 59 million light years from Earth. It was discovered on 14 April 1789 by William Herschel, and was described as "pretty faint, small, round" by John Louis Emil Dreyer, the compiler of the New General Catalogue.

NGC 5011 Elliptical galaxy in the constellation Centaurus

NGC 5011 is an elliptical galaxy in the constellation of Centaurus. It was discovered on 3 June 1834 by John Herschel. It was described as "pretty bright, considerably small, round, among 4 stars" by John Louis Emil Dreyer, the compiler of the New General Catalogue.

References

  1. 1 2 3 Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131: 1163–1183. doi:10.1086/498708. ISSN   0004-6256.
  2. 1 2 3 4 "NED results for object NGC 4861". National Aeronautics and Space Administration / Infrared Processing and Analysis Center . Retrieved 4 February 2017.
  3. 1 2 "NGC 4861". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 4 February 2017.
  4. ↑ Courtney Seligman. "New General Catalog Objects: NGC 4500 - 4599" . Retrieved 4 February 2017.
  5. 1 2 "Starbirth with a chance of winds?". www.spacetelescope.org. Retrieved 4 February 2017.
  6. 1 2 Ela, M Ozdogan; Akyuz, A.; Aksaker, N.; Avdan, S.; Oralhan, I Akkaya; Vinokurov, A.; Allak, S.; Solovyeva, Y.; Atapin, K.; Bizyaev, D. (2021). "Optical counterparts of ULXs in two dwarf galaxies: NGC 4861 and NGC 4449". Monthly Notices of the Royal Astronomical Society. 505: 771–782. arXiv: 2105.02302 . doi:10.1093/mnras/stab1321.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.