Messier 74 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Pisces [1] |
Right ascension | 01h 36m 41.8s [2] |
Declination | +15° 47′ 01″ [2] |
Redshift | 657 km/s [2] |
Distance | 30 ± 6 Mly [3] |
Apparent magnitude (V) | 9.4 [4] |
Characteristics | |
Type | SA(s)c [2] |
Number of stars | 100 billion (1×1011) |
Size | 95,000 ly (diameter) [5] |
Apparent size (V) | 10′.5 × 9′.5 [2] |
Other designations | |
NGC 628, UGC 1149, PGC 5974 [2] |
Messier 74 (also known as NGC 628 and Phantom Galaxy) is a large spiral galaxy in the equatorial constellation Pisces. [lower-alpha 1] It is about 32 million light-years away from Earth. [6] The galaxy contains two clearly defined spiral arms and is therefore used as an archetypal example of a grand design spiral galaxy. [7] The galaxy's low surface brightness makes it the most difficult Messier object for amateur astronomers to observe. [8] [9] Its relatively large angular (that is, apparent) size and the galaxy's face-on orientation make it an ideal object for professional astronomers who want to study spiral arm structure and spiral density waves. It is estimated that M74 hosts about 100 billion stars. [6]
M74 was discovered by Pierre Méchain in 1780. He then communicated his discovery to Charles Messier, who listed the galaxy in his catalog. [9]
In July 2022, it was observed by the James Webb Space Telescope.
M74 has two spiral arms that wind counterclockwise from the galaxy's center. The spiral arms widen as they get farther from M74's center, but one of the arms narrows at the end. The arms deviate slightly from a constant angle. [10]
Three supernovae are known to have taken place within it: [2] SN 2002ap, [11] SN 2003gd, [12] and SN 2013ej (the numbers denote the year). [13] The latter was bright as 10th magnitude when viewed from the surface of Earth, so visible from almost all modern telescopes in a good night sky. [13]
SN 2002ap was one of few Type Ic supernovae (which denotes hypernovae) recorded within 10 Mpc every century. [14] [15] [16] This explosion has been used to test theories on the origins of others further away [15] and theories on the emission by supernovae of gamma ray bursts. [16]
SN 2003gd is a Type II-P supernova. [17] Type II supernovae have known luminosities, so they can be used to accurately measure distances. The distance measured to M74 using SN 2003gd is 9.6 ± 2.8 Mpc, or 31 ± 9 million ly. [3] For comparison, distances measured using the brightest supergiants are 7.7 ± 1.7 Mpc and 9.6 ± 2.2 Mpc. [3] Ben Sugerman found a "light echo" – a later reflection of the explosion – associated with SN 2003gd. [18] This is one of the few supernovae in which such a reflection has been found. This reflection appears to be from dust in a sheet-like cloud that lies in front of the supernova, and it can be used to determine the composition of the interstellar dust. [18] [19]
In addition to these supernovae, the astronomical transient AT 2019krl was discovered on 6 July 2019 and classified as either a type IIn supernova or an LBV in outburst. [20] Later analysis argued that it was consistent with known examples of giant LBV eruptions and SN 2008S-like objects. [21]
This is the brightest member of the M74 Group, a group of 5 to 7 galaxies that also includes the peculiar spiral galaxy NGC 660 and a few irregular galaxies. [22] [23] [24] Different group membership identification methods (ranging from a clear, to likely, to perhaps historic gravitational tie) identify several objects of the group in common, [24] and a few galaxies whose exact status within such groupings is currently uncertain. [24]
In 2005 [25] [lower-alpha 2] the Chandra X-ray Observatory announced its observation of an ultraluminous X-ray source (ULX) in M74, radiating more X-ray power than a neutron star, in periodic intervals of around two hours. It has an estimated mass of 10000 M☉ . This is an indicator of an intermediate-mass black hole. This would be a rather uncommon class, in between in size of stellar black holes and the massive black holes theorized to be in the center of many galaxies. Such an object is believed to form from lesser ("stellar") black holes within a star cluster. The source has been given identification number CXOU J013651.1+154547.
Messier 74 is 1.5° east-northeast of Eta Piscium. [8] [9] This galaxy has the second-lowest Earth-surface brightness of any Messier object. (M101 has the lowest.) It requires a good night sky. [9] [8] This galaxy may be best viewed under low magnification; when highly magnified, the diffuse emission becomes more extended and appears too faint to be seen by many people. [9] Additionally, M74 may be more easily seen when using averted vision when the eyes are fully dark adapted. [8] [9]
The Pinwheel Galaxy is a face-on, unbarred, and counterclockwise spiral galaxy located 21 million light-years from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.
Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 17 February 1752 at the Cape of Good Hope. Charles Messier added it to his catalogue of nebulous objects in March 1781.
Messier 61 is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779, six days before Charles Messier discovered the same galaxy. Messier had observed it on the same night as Oriani but had mistaken it for a comet. Its distance has been estimated to be 45.61 million light years from the Milky Way Galaxy. It is a member of the M61 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.
The Whirlpool Galaxy, also known as Messier 51a (M51a) or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is 7.22 megaparsecs away and 23.58 kiloparsecs (76,900 ly) in diameter.
Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.
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 14 June 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.
Messier 66 or M66, also known as NGC 3627, is an intermediate spiral galaxy in the southern, equatorial half of Leo. It was discovered by French astronomer Charles Messier on 1 March 1780, who described it as "very long and very faint". This galaxy is a member of a small group of galaxies that includes M65 and NGC 3628, known as the Leo Triplet or the M66 Group. M65 and M66 are a common object for amateur astronomic observation, being separated by only 20′.
Messier 84 or M84, also known as NGC 4374, is a giant elliptical or lenticular galaxy in the constellation Virgo. Charles Messier discovered the object in 1781 in a systematic search for "nebulous objects" in the night sky. It is the 84th object in the Messier Catalogue and in the heavily populated core of the Virgo Cluster of galaxies, part of the local supercluster.
Messier 95, also known as M95 or NGC 3351, is a barred spiral galaxy about 33 million light-years away in the zodiac constellation Leo. It was discovered by Pierre Méchain in 1781, and catalogued by compatriot Charles Messier four days later. In 2012 its most recent supernova was discovered.
Messier 96 is an intermediate spiral galaxy about 31 million light-years away in the constellation Leo.
Messier 108 is a barred spiral galaxy about 28 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on.
NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.
SN 2003gd was a Type II-P supernova explosion in the Phantom Galaxy, located in the constellation Pisces. SN 2003gd was discovered on 12 June 2003 by Robert Evans, using a 0.31m reflector, and its discovery was confirmed on 13 June 2003 by R. H. McNaught using the 1.0m telescope at the Siding Spring Observatory.
NGC 7424 is a barred spiral galaxy located 37.5 million light-years away in the southern constellation Grus. Its size makes it similar to our own galaxy, the Milky Way. It is called a "grand design" galaxy because of its well defined spiral arms. Two supernovae and two ultraluminous X-ray sources have been discovered in NGC 7424.
NGC 634 is a spiral galaxy, lying at a distance of 217.1 megalight-years away from the Milky Way in the northern constellation of Triangulum. This object was discovered in the nineteenth century by French astronomer Édouard Stephan. It is inclined by an angle of 82.4° to the line of sight from the Earth, and thus is being viewed nearly edge on.
NGC 5806 is an intermediate spiral galaxy in the constellation Virgo. It was discovered on February 24, 1786, by the astronomer John Herschel. It is located about 70 million light-years away from the Milky Way. It is a member of the NGC 5846 Group.
NGC 1084 is an unbarred spiral galaxy in the constellation Eridanus. It is located at a distance of about 63 million light-years away from the Milky Way. The galaxy was discovered by William Herschel on 10 January 1785. It has multiple spiral arms, which are not well defined. It belongs in the same galaxy group with NGC 988, NGC 991, NGC 1022, NGC 1035, NGC 1042, NGC 1047, NGC 1052 and NGC 1110. This group is in turn associated with the Messier 77 group.
SN 2013ej is a Type II-P supernova in the nearby spiral galaxy Messier 74. It was discovered by the Lick Observatory Supernova Search on July 25, 2013, with the 0.76 m Katzman Automatic Imaging Telescope, with pre-discovery images having been taken the day before.
NGC 3191 is a barred spiral galaxy in the constellation Ursa Major. It is located at a distance of about 400 million light years from Earth, which, given its apparent dimensions, means that NGC 3191 is about 115,000 light years across. The galaxy has been distorted and interacts with a companion 1.3 arcminutes to the west. An extremely blue tidal bridge lies between them. It was discovered by Gaia on 23 May 2017.
NGC 3861 is a large barred spiral galaxy with a ring-like structure located about 310 million light-years away in the constellation Leo. It was discovered by astronomer John Herschel on March 23, 1827. NGC 3861 is a member of the Leo Cluster and has a normal amount of neutral hydrogen and ionised hydrogen.