NGC 4102 | |
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Observation data (J2000 epoch) | |
Constellation | Ursa Major [1] |
Right ascension | 12h 06m 23.115s [2] |
Declination | +52° 42′ 39.42″ [2] |
Redshift | 0.002792 [3] |
Heliocentric radial velocity | 837 km/s [4] |
Distance | 59.6 Mly (18.3 Mpc) [5] |
Group or cluster | Ursa Major group [6] |
Apparent magnitude (V) | 11.2 [7] |
Apparent magnitude (B) | 11.8 [8] |
Characteristics | |
Type | SAB(s)b, [9] [10] SABab [3] |
Apparent size (V) | 2.9′ × 1.8′ [7] |
Notable features | LINER [9] |
Other designations | |
IRAS 12038+5259, 2MASX J12062311+5242394, WISE J120623.07+524239.8, UGC 7096, LEDA 38392, MCG MCG+09-20-094, PGC 38392, SDSS J120623.00+524240.1 [8] |
NGC 4102 is an intermediate [9] barred spiral galaxy located in the northern constellation of Ursa Major. It is visible in a small telescope and has an apparent visual magnitude of 11.2. [7] The galaxy was discovered April 12, 1789 by William Herschel. J. L. E. Dreyer described it as "bright, pretty small, round, brighter middle and bright nucleus". [11] This galaxy is located at a distance of 60 [5] million light years and is receding with a heliocentric radial velocity of 837 km/s. [4] It is a member of the Ursa Major group of galaxies. [6]
The morphological class of NGC 4102 is SABab [3] or SAB(s)b?, [10] which is a spiral galaxy with a bar-like feature around the core (SAB), no inner ring structure (s), and moderately tightly-wound spiral arms ('ab' or 'b'). However, the bar in this galaxy is considered particularly small for galaxies of this class. [10] The galactic plane is inclined at an angle of 56°±2° to the line of sight from the Earth. [12] NGC 4102 has a region of intense star formation in the nuclear region, known as a starburst region. [6] This volume is 1,000 ly (310 pc) in diameter containing some 3 billion solar masses. [13] An outflow of hydrogen has been detected, extending outward to the northwest as far as 6.3 kpc (21 kly) from the nucleus. [14]
The core of NHC 4102 is almost certainly an active galactic nucleus (AGN), [15] which indicates it has a supermassive black hole (SMBH) that is generating energy by accreting material. [16] It is an X-ray source with a spectrum similar to a Seyfert 2 galaxy. [15] This type of AGN is known as a Type-2 LINER, or low-ionization nuclear emission-line region. This is due to a core that is obscured by intervening dusty materials and/or the SMBH is accreting material in an inefficient manner. The bolometric luminosity of the active nucleus is ~7×1043 erg ·s−1. [16]
One supernova has been observed in NGC 4102: SN 1975E (type unknown, mag. 16.7). [17]
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that the luminosity is not produced by stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.
A supermassive black hole 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 (M☉). Black holes are a class of astronomical objects that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, not even light. Observational evidence indicates that almost every large galaxy has a supermassive black hole at its center. For example, the Milky Way galaxy has a supermassive black hole at its center, corresponding to the radio source Sagittarius A*. Accretion of interstellar gas onto supermassive black holes is the process responsible for powering active galactic nuclei (AGNs) and quasars.
Messier 63 or M63, also known as NGC 5055 or the seldom-used Sunflower Galaxy, is a spiral galaxy in the northern constellation of Canes Venatici with approximately 400 billion stars. M63 was first discovered by the French astronomer Pierre Méchain, then later verified by his colleague Charles Messier on June 14, 1779. The galaxy became listed as object 63 in the Messier Catalogue. In the mid-19th century, Anglo-Irish astronomer Lord Rosse identified spiral structures within the galaxy, making this one of the first galaxies in which such structure was identified.
NGC 4395 is a nearby low surface brightness spiral galaxy located about 14 million light-years from Earth in the constellation Canes Venatici. The nucleus of NGC 4395 is active and the galaxy is classified as a Seyfert Type I known for its very low-mass supermassive black hole. It is one of the lowest
NGC 1300 is a barred spiral galaxy located about 61 million light-years away in the constellation Eridanus. The galaxy is about 110,000 light-years across. It is a member of the Eridanus Cluster, a cluster of 200 galaxies. It was discovered by John Herschel in 1835.
NGC 3227 is an intermediate spiral galaxy that is interacting with the dwarf elliptical galaxy NGC 3226. The two galaxies are one of several examples of a spiral with a dwarf elliptical companion that are listed in the Atlas of Peculiar Galaxies. Both galaxies may be found in the constellation Leo. It is a member of the NGC 3227 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.
NGC 5548 is a Type I Seyfert galaxy with a bright, active nucleus. This activity is caused by matter flowing onto a 65 million solar mass (M☉) supermassive black hole at the core. Morphologically, this is an unbarred lenticular galaxy with tightly-wound spiral arms, while shell and tidal tail features suggest that it has undergone a cosmologically-recent merger or interaction event. NGC 5548 is approximately 245 million light years away and appears in the constellation Boötes. The apparent visual magnitude of NGC 5548 is approximately 13.3 in the V band.
The Eyes Galaxies are a pair of galaxies about 52 million light-years away in the constellation Virgo. The pair are members of the string of galaxies known as Markarian's Chain.
NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by the astronomer James Dunlop on November 5, 1826. It was originally unclear whether it was a member of the Dorado Group, with some sources finding it to be a member and other sources rejecting its membership. However, recent tip of the red-giant branch (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group.
NGC 3593 is a lenticular galaxy located in the constellation Leo. It has a morphological classification of SA(s)0/a, which indicates it is a lenticular galaxy of the pure spiral type. Despite this, it has a large amount of hydrogen, both in its molecular and atomic (H) form. It is a starburst galaxy, which means it is forming new stars at a high rate. This is occurring in a band of gas surrounding the central nucleus. There is a single arm, which spirals outward from this ring. It is frequently but not consistently identified as a member of the Leo Triplet group.
NGC 4041 is the New General Catalogue identifier for a spiral galaxy in the northern circumpolar constellation of Ursa Major. It is located an estimated 70 million light years from the Sun. The morphological classification of SA(rs)bc indicates this is a spiral galaxy the lacks a bar; the 'rs' means it has a weakly-formed ring structure, and the 'bc' indicates the spiral arms are moderately to loosely wound.
NGC 4293 is a lenticular galaxy in the northern constellation of Coma Berenices. It was discovered by English astronomer William Herschel on March 14, 1784, who described it as "large, extended, resolvable, 6 or 7′ long". This galaxy is positioned to the north-northwest of the star 11 Comae Berenices and is a member of the Virgo Cluster of galaxies. It is assumed to lie at the same distance as the Virgo Cluster itself: around 54 million light years away. The galaxy spans an apparent area of 5.3 × 3.1 arc minutes.
NGC 4424 is a spiral galaxy located in the equatorial constellation of Virgo. It was discovered February 27, 1865 by German astronomer Heinrich Louis d'Arrest. This galaxy is located at a distance of 13.5 million light years and is receding with a heliocentric radial velocity of 442 km/s. It has a morphological class of SB(s)a, which normally indicates a spiral galaxy with a barred structure (SB), no inner ring feature (s), and tightly-wound spiral arms (a). The galactic plane is inclined at an angle of 62° to the line of sight from the Earth. It is a likely member of the Virgo Cluster of galaxies.
NGC 3675 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 3675 is about 100,000 light years across. It was discovered by William Herschel in 1788.
NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.
NGC 6951 is a barred spiral galaxy located in the constellation Cepheus. It is located at a distance of about 75 million light-years from Earth, which, given its apparent dimensions, means that NGC 6951 is about 100,000 light-years across. It was discovered by Jérôme Eugène Coggia in 1877 and independently by Lewis Swift in 1878.
IC 1459 is an elliptical galaxy located in the constellation Grus. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that IC 1459 is about 130,000 light-years across. It was discovered by Edward Emerson Barnard in 1892.
NGC 5728 is an active barred spiral galaxy located 146 million light years away in the southern constellation of Libra. It was discovered on May 7, 1787 by William Herschel. The designation comes from the New General Catalogue of J. L. E. Dreyer, published in 1888. It has an apparent visual magnitude of 13.40 and spans an angle of 3.4 arcminutes. The galaxy shows a red shift of 0.00935 and has a heliocentric radial velocity of 2,803 km/s. It has an estimated mass of 72 billion times the mass of the Sun and stretches around 30 kpc across.
NGC 2617 is a Seyfert galaxy in the equatorial constellation of Hydra. It was discovered on February 12, 1885, by French astronomer Édouard Stephan. In 1888, Danish astronomer J. L. E. Dreyer described it as "extremely faint, very small, 2 very faint stars involved". It is located at an estimated distance of 202 million light years. In the infrared, the galaxy has an angular size of 0.693 by 0.652 arcminutes.