NGC 4487 is aspiral galaxy in the constellationVirgo. The galaxy lies about 55 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 4487 is approximately 65,000 light years across.[1] It was discovered byWilliam Herschel on March 23, 1789.[3]
NGC 4487 has an ellipticalbulge with a small bar. The nucleus is offset from the centre. The galaxy has faint diffusespiral arms.[4] Two spiral arms can be discerned with agrand design pattern. Dust lanes are visible along the inner regions of the arms. One arm branches into several broad segments. ManyHII regions are visible in the disk, the largest of which are more than 3 arcseconds across.[5]
Based on its X-ray emission the nucleus of the galaxy appears to beactive.[6] In the centre of the galaxy lies asupermassive black hole, whose mass is estimated to be 106.46 ± 0.63 (0.6 - 12 million)M☉, based on the pitch angle of the spiral arms.[7] The stars of the galaxy appear to be of intermediate-young age and have very lowmetallicity.[8] The star formation rate is estimated to be 0.4M☉ per year.[9]
Onesupernova has been observed in NGC 4487, SN 2009N. It was discovered on 24 January 2009 byKoichi Itagaki at an apparent magnitude of 16.6, located 75" east and 18" north of the center of NGC 4487.[10] It was identified as atype II supernova.[11] More detailed spectral observations categorised it as a type II-P, created by the collapse ofred supergiant or ayellow supergiant.[12]
NGC 4487 forms a pair withNGC 4504, which lies 35 arcminutes away.[5] NGC 4487 is a member of the Messier 104 Group, which also includes theSombrero Galaxy (M104), NGC 4504, UGCA 287, and UGCA 289.[13] A. M. Garcia considers the galaxy part of the LGG 293 Group, in which are included the galaxies NGC 4487, NGC 4504, andNGC 4597.[14] It is part of aVirgo II Groups, a chain of groups extending from theVirgo Cluster.[15]
^Eskridge, Paul B.; Frogel, Jay A.; Pogge, Richard W.; Quillen, Alice C.; Berlind, Andreas A.; Davies, Roger L.; DePoy, D. L.; Gilbert, Karoline M.; Houdashelt, Mark L.; Kuchinski, Leslie E.; Ramirez, Solange V.; Sellgren, K.; Stutz, Amelia; Terndrup, Donald M.; Tiede, Glenn P. (November 2002). "Near-Infrared and Optical Morphology of Spiral Galaxies".The Astrophysical Journal Supplement Series.143 (1):73–111.arXiv:astro-ph/0206320.Bibcode:2002ApJS..143...73E.doi:10.1086/342340.
^abSandage, A., Bedke, J. (1994),The Carnegie Atlas of Galaxies. Volume I, Carnegie Institution of Washington
^Davis, Benjamin L.; Berrier, Joel C.; Johns, Lucas; Shields, Douglas W.; Hartley, Matthew T.; Kennefick, Daniel; Kennefick, Julia; Seigar, Marc S.; Lacy, Claud H. S. (20 June 2014). "The Black Hole Mass Function Derived from Local Spiral Galaxies".The Astrophysical Journal.789 (2): 124.arXiv:1405.5876.Bibcode:2014ApJ...789..124D.doi:10.1088/0004-637X/789/2/124.S2CID119302157.
