The Black Eye Galaxy (also called Sleeping Beauty Galaxy or Evil Eye Galaxy and designated Messier 64, M64, or NGC 4826) is a relatively isolated[7]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.[11][12] M64 is well known among
amateur astronomers due to its form in small
telescopes and visibility across inhabited latitudes.
This galaxy is inclined 60° to the
line-of-sight and has a
position angle of 112°.[7] At the distance of this galaxy, it has a linear scale of 65 ly (20
pc) per arcsecond.[7] The
morphological classification in the
De 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.[13] Ann et al. (2015) gave it a class of SABa,[14] suggesting a weakly
barred spiral galaxy with tightly wound arms.
M64 is a type 2
Seyfert galaxy[15] with an
HII/
LINER nucleus. The central region is a weak source of radio emission.[7] A soft
X-ray source has been detected at the nucleus, which is most likely coming from the circumnuclear region rather than directly from an
active galactic nucleus.[16] 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 of
star formation, with also approximately 100 billion stars inside the galaxy.[11] There is also evidence of a recent large inflow of mass.[17]
The
interstellar medium of Messier 64 consists of two
counter-rotating disks that are approximately equal in mass.[18] The inner disk contains the prominent
dust lanes of the galaxy. The stellar population of the galaxy exhibits no measurable counter-rotation.[19] Possible formation scenarios include a merger with a gas-rich satellite galaxy in a retrograde orbit, or the continued accretion of
gas clouds from the
intergalactic medium.[18][19] It has a diameter of 16.51
kiloparsecs (53,800
light-years).[9]
^
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.