NGC 6781 | |
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Observation data (J2000 epoch) | |
Constellation | Pavo |
Right ascension | 19h 23m 57.935s [1] |
Declination | −59° 55′ 21.04″ [1] |
Redshift | 0.012462±0.000123 [2] |
Heliocentric radial velocity | 3,736 km/s [3] |
Distance | 173 Mly (53 Mpc) [3] |
Apparent magnitude (V) | 11.8 [4] |
Characteristics | |
Type | (R1R′2)SB(r)a [5] |
Apparent size (V) | 1′.197 × 0′.814 [1] (NIR) |
Other designations | |
LEDA 63168, ESO 142-1, 2MASX J19235793-5955210, NGC 6782, PGC 63168 [6] |
NGC 6782 is a barred spiral galaxy located in the southern constellation of Pavo, at a distance of approximately 173 megalight-years from the Milky Way. [3] It was discovered on July 12, 1834 by English astronomer John Herschel. John L. E. Dreyer described it as, "considerably faint, considerably small, round, a little brighter middle, 9th magnitude star to south". [7] The morphological classification of NGC 6782 is (R1R′2)SB(r)a, indicating a barred spiral galaxy with a multiple ring system and tightly-wound spiral arms. [5] It is seen nearly face-on, [8] being inclined by an angle of 27.2°±0.2° to the line of sight from the Earth. [5]
At the galactic core is an almost circular nuclear ring at the inner Lindblad resonance. This is attached to the primary bar, which extends out to a somewhat pointy, diamond-shaped inner ring. It is actually a double-barred galaxy, with an interior bar inside the nuclear ring. A pair of faint spiral arms extend out from the inner ring to the outer parts of the galaxy, where it joints a double outer ring system. [5] Both inner rings of the galaxy are undergoing star formation, producing hot OB stars, with little star formation occurring in the remainder. [8]
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 4725 is an intermediate barred spiral galaxy with a prominent ring structure, located in the northern constellation of Coma Berenices near the north galactic pole. It was discovered by German-born British astronomer William Herschel on April 6, 1785. The galaxy lies at a distance of approximately 40 megalight-years from the Milky Way. NGC 4725 is the brightest member of the Coma I Group of the Coma-Sculptor Cloud, although it is relatively isolated from the other members of this group. This galaxy is strongly disturbed and is interacting with neighboring spiral galaxy NGC 4747, with its spiral arms showing indications of warping. The pair have an angular separation of 24′, which corresponds to a projected linear separation of 370 kly. A tidal plume extends from NGC 4747 toward NGC 4725.
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 3486 is an intermediate barred spiral galaxy located about 27.4 million light years away in the constellation of Leo Minor. It has a morphological classification of SAB(r)c, which indicates it is a weakly barred spiral with an inner ring and loosely wound arms. This is a borderline, low-luminosity Seyfert galaxy with an active nucleus. However, no radio or X-ray emission has been detected from the core, and it may only have a small supermassive black hole with less than a million times the mass of the Sun.
NGC 520 is a pair of colliding spiral galaxies about 105 million light-years away in the constellation Pisces. They were discovered by astronomer William Herschel on 13 December 1784.
NGC 4319 is a face-on barred spiral galaxy located about 77 million light years away in the constellation Draco. The morphological classification is SB(r)ab, which indicates it is a barred spiral with an inner ring structure and moderate to tightly wound arms. It is situated in physical proximity to the galaxies NGC 4291 and NGC 4386, with X-ray emissions from the intervening gap indicating NGC 4319 and NGC 4291 may be interacting. NGC 4319 has a much higher proportion of ionized hydrogen compared to the Milky Way galaxy.
NGC 3344 is a relatively isolated barred spiral galaxy located 22.5 million light years away in the constellation Leo Minor. This galaxy belongs to the group known as the Leo spur, which is a branch of the Virgo Supercluster. NGC 3344 has the morphological classification (R)SAB(r)bc, which indicates it is a weakly barred spiral galaxy that exhibits rings and moderate to loosely wound spiral arms. There is both an inner and outer ring, with the prominent arms radiating outward from the inner ring and the slightly elliptical bar being situated inside. At the center of the bar is an HII nucleus with an angular diameter of about 3″. NGC 3344 hosted supernova SN 2012fh, which was shown to likely be a Type Ib or Type Ic.
NGC 3169 is a spiral galaxy about 75 million light years away in the constellation Sextans. It has the morphological classification SA(s)a pec, which indicates this is a pure, unbarred spiral galaxy with tightly-wound arms and peculiar features. There is an asymmetrical spiral arm and an extended halo around the galaxy. It is a member of the NGC 3166 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 5754 is a barred spiral galaxy located 218 million light years away in the constellation Boötes. It is a member of the Arp 297 interacting galaxies group, which consists of NGC 5752, NGC 5753, NGC 5754, NGC 5755. Along with NGC 2718 and UGC 12158, NGC 5754 is often considered a Milky Way-twin.
NGC 4911 is a disturbed, warped spiral galaxy with a bright prominent central starburst ring and located deep within the Coma Cluster of galaxies, which lies some 300 million light years away in the northern constellation Coma Berenices. NGC 4911 is believed to be interacting with its warped, barred lenticular companion, producing the enhanced star formation and shell-like appearance seen in optical images. The galaxy contains rich lanes of dust and gas near its centre. The existence of clouds of hydrogen within the galaxy indicates ongoing star formation. It is rare for a spiral galaxy to be situated at the heart of a cluster.
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 4535 is a barred spiral galaxy located some 54 million light years from Earth in the constellation Virgo. It is a member of the Virgo Cluster of galaxies and is located 4.3° from Messier 87. The galactic plane of NGC 4535 is inclined by an angle of 43° to the line of sight from the Earth. The morphological classification of NGC 4535 in the De Vaucouleurs system is SAB(s)c, which indicates a bar structure across the core (SAB), no ring (s), and loosely wound spiral arms (c). The inner part of the galaxy has two spiral arms, which branch into multiple arms further away. The small nucleus is of type HII, meaning the spectrum resembles that of an H II region.
NGC 4698 is a barred spiral galaxy located around 55 million light years away from Earth in the constellation of Virgo. It belongs to the Virgo Cluster of galaxies and is positioned near the northeastern edge of this assemblage. The morphological classification of NGC 4698 in the De Vaucouleurs system is SA(s)ab, which indicates a purely spiral structure with moderate to tightly wound arms. It is inclined to the line of sight from the Earth by an angle of 53° along a position angle of 170°.
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 4178 is the New General Catalogue identifier for a barred spiral galaxy in the equatorial constellation of Virgo. It was discovered April 11, 1825 by English astronomer John Herschel. Located some 43.8 million light years away, this galaxy spans 2.3 × 0.4 arc minutes and is seen at a low angle, being inclined by 77° to the line of sight from the Earth. The morphological classification of NGC 4178 is SB(rs)dm, indicating that it has a bar feature at the core, and, per the '(rs)', has traces of a ring-like structure surrounding the bar. The 'dm' suffix indicates the spiral arms are diffuse, broken, and irregular in appearance with no bulge at the nucleus. This galaxy is a member of the Virgo Cluster, which is the richest nearby group of galaxies outside the Local Group and forms the core of the Virgo Supercluster.
NGC 1614 is the New General Catalogue identifier for a spiral galaxy in the equatorial constellation of Eridanus. It was discovered on December 29, 1885 by American astronomer Lewis Swift, who described it in a shorthand notation as: pretty faint, small, round, a little brighter middle. The nebula was then catalogued by Danish-Irish astronomer J. L. E. Drayer in 1888. When direct photography became available, it was noted that this galaxy displayed some conspicuous peculiarities. American astronomer Halton Arp included it in his 1966 Atlas of Peculiar Galaxies. In 1971, Swiss astronomer Fritz Zwicky described it as a "blue post-eruptive galaxy, compact patchy core, spiral plumes, long blue jet SSW".
NGC 3081 is a barred lenticular ring galaxy in the constellation of Hydra. NGC 3081 is located about 85 million light-years away from Earth, which means, given its apparent dimensions, that NGC 3081 is approximately 60,000 light-years across. It is a type II Seyfert galaxy, characterised by its bright nucleus. It was discovered by William Herschel on 21 December 1786.
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. It is classified as a Seyfert galaxy.
NGC 3175 is a spiral galaxy located in the far eastern part of the southern constellation of Antlia at an approximate distance of 54 million light-years. NGC 3175 was discovered on March 30, 1835 by English astronomer John Herschel, whose notes described it as, "considerably bright, large, much extended NE-SW, very gradually little brighter middle". This galaxy is the namesake of the NGC 3175 group of galaxies, which includes the spiral galaxy NGC 3137.