TheBlack Eye Galaxy (also calledSleeping Beauty Galaxy orEvil Eye Galaxy and designatedMessier 64,M64, orNGC 4826) is a relatively isolated[7]spiral galaxy 17 millionlight-years away in the mildly northernconstellation ofComa Berenices. It was discovered byEdward Pigott in March 1779, and independently byJohann Elert Bode in April of the same year, as well as byCharles Messier the next year. A dark band ofabsorbing dust partially in front of its bright nucleus gave rise to its nicknames of the "Black Eye", "Evil Eye", or "Sleeping Beauty" galaxy.[12][13] M64 is well known amongamateur astronomers due to its form in smalltelescopes and visibility across inhabited latitudes.
This galaxy is inclined 60° to theline-of-sight and has aposition angle of 112°.[7] At the distance of this galaxy, it has a linear scale of 65 ly (20 pc) per arcsecond.[7] Themorphological classification in theDe Vaucouleurs system is (R)SA(rs)ab,[4] where the '(R)' indicates an outer ring-like structure, 'SA' denotes a non-barred spiral, '(rs)' means a transitional inner ring/spiral structure, and 'ab' says the spiral arms are fairly tightly wound.[14] Ann et al. (2015) gave it a class of SABa,[15] suggesting a weaklybarred spiral galaxy with tightly wound arms.
M64 is a type 2Seyfert galaxy[16] with anHII/LINER nucleus. The central region is a weak source of radio emission.[7] A softX-ray source has been detected at the nucleus, which is most likely coming from the circumnuclear region rather than directly from anactive galactic nucleus.[17] There is an inner disk of molecular gas that is truncated at a radius of 2,300 ly (700 pc). At present, the non-rotational motions of this disk do not significantly feed the core, but the disk does produce a vigorous rate ofstar formation, with also approximately 100 billion stars inside the galaxy.[12] There is also evidence of a recent large inflow of mass.[18] The centralsupermassive black hole is calculated to have a mass of about8.4×106M☉.[9]
Theinterstellar medium of Messier 64 consists of twocounter-rotating disks that are approximately equal in mass.[19] The inner disk contains the prominentdust lanes of the galaxy. The stellar population of the galaxy exhibits no measurable counter-rotation.[20] Possible formation scenarios include a merger with a gas-rich satellite galaxy in a retrograde orbit, or the continued accretion ofgas clouds from theintergalactic medium.[19][20] It has a diameter of 16.51kiloparsecs (53,800light-years).[10]
^abSkrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006)."The Two Micron All Sky Survey (2MASS)".The Astronomical Journal.131 (2):1163–1183.Bibcode:2006AJ....131.1163S.doi:10.1086/498708.ISSN0004-6256.S2CID18913331.
^abcde Vaucouleurs, G.; et al. (1991),Third reference catalogue of bright galaxies, 9, New York:Springer-Verlag.
