The plane of the galactic disk is inclined at an angle of 68° to the line of sight from the Earth.[4] The galaxy has a faint bar which near its ends, were the spiral arms begin, has ansae. The galaxy has two spiral arms which can be followed for more than 180 degrees. The arms are patchy and fragmented[5] and feature small star forming areas visible inH alpha. There is also H alpha emission from the nucleus.[6] Innear infrared the bulge appears more pronounced and the outer arms have low surface brightness.[5]
The stellar mass of the galaxy is estimated to be1010.5M☉.[4] In the centre of the galaxy is predicted to lie asupermassive black hole whose mass is estimated to be between 1.2 and 7.2 millionsolar masses, based on the spiral arm pitch angle.[7]
^abEskridge, 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.
^Schmitt, H. R.; Calzetti, D.; Armus, L.; Giavalisco, M.; Heckman, T. M.; Kennicutt, Jr., R. C.; Leitherer, C.; Meurer, G. R. (May 2006). "Multiwavelength Star Formation Indicators: Observations".The Astrophysical Journal Supplement Series.164 (1):52–80.arXiv:astro-ph/0602063.doi:10.1086/501529.
^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.doi:10.1088/0004-637X/789/2/124.
^Schmidt, M.; Kowal, C. T. (26 February 1974)."Supernova in NGC 5161".Central Bureau for Astronomical Telegrams.2640. Smithsonian Astrophysical Observatory,IAU: 1. Retrieved16 August 2025.
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