Messier 74 (also known asNGC 628 andPhantom Galaxy) is a largespiral galaxy in theequatorialconstellationPisces.[a] It is about 32 million light-years away from Earth.[3] The galaxy contains two clearly definedspiral arms and is therefore used as an archetypal example of agrand design spiral galaxy.[4] The galaxy's low surface brightness makes it the most difficultMessier object for amateur astronomers to observe.[5][6] 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 studyspiral arm structure andspiral density waves. It is estimated that M74 hosts about 100 billion stars.[3]
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.[7]
SN 2002ap (TypeIc, mag. 14.5) was discovered by Yoji Hirose on 29 January 2002.[8][9] It was one of few Type Ic supernovae (which denoteshypernovae) recorded within 10 Mpc every century.[10][11][12] This explosion has been used to test theories on the origins of others further away[11] and theories on the emission by supernovae ofgamma ray bursts.[12] It got as bright as magnitude 12.3, making it the brightest supernova of 2002.[13]
SN 2003gd (TypeII-P, mag. 13.2) was discovered byRobert Evans on 12 June 2003.[14][15][16] Type II supernovae have knownluminosities, 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.[17] For comparison, distances measured using the brightest supergiants are 7.7 ± 1.7 Mpc and 9.6 ± 2.2 Mpc.[17] 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]
SN 2013ej (Type II-P, mag. 13.5) was discovered by theLick Observatory Supernova Search (LOSS) on 25 July 2013.[20][21] It was bright as 10th magnitude when viewed from the surface of Earth, so it was visible from almost all modern telescopes ina good night sky.[22]
In addition to these supernovae, theastronomical transientAT 2019krl was discovered by Anna Ho on 6 July 2019, and classified as either atype IIn supernova or anLBV in outburst.[23][24] Later analysis argued that it was consistent with known examples of giant LBV eruptions andSN 2008S-like objects.[25]
This is the brightest member of theM74 Group, a group of 5 to 7 galaxies that also includes thepeculiarspiral galaxyNGC 660 and a fewirregular galaxies.[26][27][28] Different group membership identification methods (ranging from a clear, to likely, to perhaps historic gravitational tie) identify several objects of the group in common,[28] and a few galaxies whose exact status within such groupings is currently uncertain.[28]
In 2005[29][b] theChandra X-ray Observatory announced its observation of anultraluminous X-ray source (ULX) in M74, radiating more X-ray power than aneutron star, in periodic intervals of around two hours. It has an estimated mass of10000M☉. This is an indicator of anintermediate-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 ofEta Piscium.[5][6] This galaxy has the second-lowest Earth-surface brightness of any Messier object. (M101 has the lowest.) It requires agood night sky.[6][5] 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.[6] Additionally, M74 may be more easily seen when usingaverted vision when the eyes are fullydark adapted.[5][6]
^Kim, M.; Zheng, W.; Li, W.; Filippenko, A. V.; Cenko, S. B.; Richmond, M. W.; Amorim, A.; Balam, D. D.; Graham, M. L.; Hsiao, E. Y. (2013-07-01). "Supernova 2013ej in M74 = Psn J01364816+1545310".Central Bureau Electronic Telegrams.3606: 1.Bibcode:2013CBET.3606....1K.
^"SN 2013ej".Transient Name Server.IAU. Retrieved22 August 2025.
