NGC 1241 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Eridanus |
Right ascension | 03h 11m 14.6s [1] |
Declination | −08° 55′ 20″ [1] |
Redshift | 0.016652 ± 0.000020 [1] |
Heliocentric radial velocity | 4,052 ± 4 km/s [1] |
Distance | 144 ± 36 Mly (44.1 ± 11 Mpc) [1] |
Apparent magnitude (V) | 12.2 [2] |
Characteristics | |
Type | SB(rs)b [1] |
Apparent size (V) | 3.3′ × 2.2′ |
Notable features | Seyfert galaxy |
Other designations | |
ARP 304, MCG -02-09-011, VV 334a, Holmberg 068A, PGC 11887 [1] |
NGC 1241 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 1241 is about 140,000 light years across. It was discovered by William Herschel on January 10, 1785. [3] It is classified as a Seyfert galaxy.
NGC 1241 interacts with its smaller companion NGC 1242, forming a pair collectively known in the Atlas of Peculiar Galaxies as Arp 304.
NGC 1241 is a barred spiral galaxy seen at an inclination. It has two well defined dusty spiral arms, and thus is characterised as a grand design spiral galaxy. [4] The bulge is boxy, characteristic of a barred galaxy, with the arms emerging from each end of the bar, with the north one appearing more tightly wound than the southern. [5] The main arms branch into smaller ones.
A circumnuclear ring with active star formation has been detected in the central region of the galaxy. [6] It appears clumpy and inclined and measures 5.6 × 3.4 arcseconds in diameter, lying just inside the inner Lindblad resonance. A faint spiral pattern with leading arms has been found to emanate from it in Paα emission, while in Ks and J band, the pattern appears trailing. [7] NGC 1241 is one of the few galaxies with known trailing features in the nuclear regions, with the other being NGC 6902. [8] Inside the circumnuclear ring was detected a bar like feature 1.6 arcseconds long that is almost perpendicular to the main bar of the galaxy. [7]
The nucleus of NGC 1241 has been found to be active and it has been categorised as a type II Seyfert galaxy. [9] The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 1241 is estimated to be 107.46 (29 million) M☉. [10]
The star formation rate of NGC 1241 is estimated to be 3.07 M☉ per year based on the H-alpha flux. [11]
NGC 1241 forms a pair with NGC 1242, which lies at an angular separation of 1.6 arcminutes. NGC 1243 lies 3.1 arcminutes away, but it has been identified as a double star in our galaxy. According to Garcia et al. the pair of galaxies is part of a galaxy group known as LGG 84, which also includes the galaxies NGC 1247, MCG -02-09-006, and Markarian 1071. [12] A more recent study placed NGC 1241 in the same group as the galaxies NGC 1185, NGC 1204, NGC 1214, NGC 1215, NGC 1238, and NGC 1247. [13]
The Black Eye Galaxy is a relatively isolated spiral galaxy 17 million light-years away in the mildly northern constellation of Coma Berenices. It was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier the next year. A dark band of absorbing dust partially in front of its bright nucleus gave rise to its nicknames of the "Black Eye", "Evil Eye", or "Sleeping Beauty" galaxy. M64 is well known among amateur astronomers due to its form in small telescopes and visibility across inhabited latitudes.
Messier 77 (M77), also known as NGC 1068 or the Squid Galaxy, is a barred spiral galaxy in the constellation Cetus. It is about 47 million light-years (14 Mpc) away from Earth. Messier 77 was discovered by Pierre Méchain in 1780, who originally described it as a nebula. Méchain then communicated his discovery to Charles Messier, who subsequently listed the object in his catalog. Both Messier and William Herschel described this galaxy as a star cluster. Today, however, the object is known to be a galaxy.
NGC 2787 is a barred lenticular galaxy approximately 24 million light-years away in the northern constellation of Ursa Major. It was discovered on December 3, 1788 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "bright, pretty large, a little extended 90°, much brighter middle, mottled but not resolved, very small (faint) star involved to the southeast". The visible galaxy has an angular size of 2.5 × 1.5 arcminutes or 3.24 × 1.81 arcminutes and an apparent visual magnitude of 11.8.
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.
A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission. The spectra typically include line emission from weakly ionized or neutral atoms, such as O, O+, N+, and S+. Conversely, the spectral line emission from strongly ionized atoms, such as O++, Ne++, and He+, is relatively weak. The class of galactic nuclei was first identified by Timothy Heckman in the third of a series of papers on the spectra of galactic nuclei that were published in 1980.
NGC 5930 is a starburst galaxy in the constellation Boötes that is interacting with the nearby Seyfert galaxy NGC 5929. 5930 has a morphological classification of SAB(rs)b pec, indicating that it is a weakly-barred spiral galaxy with a poorly defined nuclear ring structure. It is inclined at an angle of 46° to the line of sight from the Earth.
NGC 1022 is a barred spiral galaxy located approximately 68 million light years away in the equatorial constellation of Cetus. It was discovered on September 10, 1785, by William Herschel. NGC 1022 is a member of the Cetus-Aries group of galaxies.
NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.
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 7130 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.
NGC 7674 is a spiral galaxy located in the constellation Pegasus. It is located at a distance of circa 350 million light years from Earth, which, given its apparent dimensions, means that NGC 7674 is about 125,000 light years across. It was discovered by John Herschel on August 16, 1830.
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.
NGC 759 is an elliptical galaxy located 230 million light-years away in the constellation Andromeda. NGC 759 was discovered by astronomer by Heinrich d'Arrest on September 17, 1865. It is a member of Abell 262.
NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth, which, given its apparent dimensions, means that NGC 1386 is about 50,000 light years across. It is a Seyfert galaxy, the only one in Fornax Cluster.
NGC 3511 is an intermediate spiral galaxy located in the constellation Crater. It is located at a distance of circa 45 million light years from Earth, which, given its apparent dimensions, means that NGC 3511 is about 70,000 light years across. It was discovered by William Herschel on December 21, 1786. It lies two degrees west of Beta Crateris.
NGC 5363 is a lenticular galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 5363 is about 100,000 light years across. It was discovered by William Herschel on January 19, 1784. It is a member of the NGC 5364 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.
NGC 2964 is an intermediate spiral galaxy located in the constellation Leo. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 2964 is about 60,000 light years across. It was discovered by William Herschel on December 7, 1785.
NGC 5135 is a barred spiral galaxy located in the constellation Hydra. It is located at a distance of about 200 million light years from Earth. It was discovered by John Herschel on May 8, 1834. It is a Seyfert galaxy.