{{Short description|Galaxy in the constellation Coma Berenices}} {{Infobox Galaxy | name = NGC 4556 | image = [[File:NGC4556 - SDSS DR14.jpg|250px]] | caption = [[Sloan Digital Sky Survey|SDSS]] image of NGC 4556. | constellation name = [[Coma Berenices (constellation)|Coma Berenices]] | epoch = J2000 | ra = {{RA|12|35|45.8}}<ref name="ned" /> | dec = {{DEC|26|54|32}}<ref name="ned" /> | type = cD, E+<ref name="ned">{{cite web | website=NASA/IPAC Extragalactic Database | title=Results for object NGC 4556 | publisher = [[NASA]] and [[California Institute of Technology|Caltech]] | url=https://ned.ipac.caltech.edu/byname?objname=NGC+4556 | access-date=2025-07-18}}</ref> | dist_ly = {{convert|105|Mpc|Mly|abbr=on|lk=on|order=flip}} | z = 0.024764<ref name="ned" /> | h_radial_v = 7424 km/s<ref name="ned" /> | appmag_v = 13.8<ref name="ned" /> |absmag_b=-22.89<ref name="ned"/> | size_v = {{Val|1.35|×|0.93|u=arcminute}}{{r|ned}} |size=~{{convert|51.36|kpc|ly|abbr=on|lk=on|order=flip}} (estimated)<ref name ="ned" /> | names = UGC 07765, CGCG 159-022, MCG +05-30-027, PGC 041980<ref name="ned" /> }}
'''NGC 4556''' is an [[elliptical galaxy]] and a [[Type-cD galaxy|cD galaxy]] located 340 million [[Light-year|light-years]] away<ref>{{Cite web |title=Your NED Search Results |url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=NGC%204556&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA%20or%20Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES |access-date=2025-07-18 |website=ned.ipac.caltech.edu}}</ref> in the [[constellation]] [[Coma Berenices]]. It was discovered on April 11, 1785, by astronomer [[William Herschel]].<ref>{{Cite web |title=New General Catalog Objects: NGC 4550 - 4599 |url=https://cseligman.com/text/atlas/ngc45a.htm#4556 |access-date=2025-07-18 |website=cseligman.com}}</ref> NGC 4556 is a member of a group of 12 galaxies known as [T2015] nest 100082, or the [[NGC 4555 Group]],<ref>{{Cite journal |last=Tully |first=R. Brent |date=May 2015 |title=Galaxy Groups: A 2MASS Catalog |url=https://ui.adsabs.harvard.edu/abs/2015AJ....149..171T/abstract |journal=The Astronomical Journal |language=en |volume=149 |issue=5 |pages=171 |doi=10.1088/0004-6256/149/5/171 |issn=0004-6256|arxiv=1503.03134 |bibcode=2015AJ....149..171T }}</ref> and is part of the [[Coma Supercluster]].<ref>{{Cite journal |last1=Gregory |first1=S. A. |last2=Thompson |first2=L. A. |date=June 1978 |title=The Coma/A1367 supercluster and its environs |url=http://adsabs.harvard.edu/doi/10.1086/156198 |journal=The Astrophysical Journal |language=en |volume=222 |pages=784 |doi=10.1086/156198 |bibcode=1978ApJ...222..784G |issn=0004-637X}}</ref><ref>{{Cite journal |last1=Jaffe |first1=W. |last2=Gavazzi |first2=G. |date=February 1986 |title=Radio continuum survey of the coma/A1367 supercluster. II. 1.5 GHz observations of 396 CGCG galaxies. |url=https://ui.adsabs.harvard.edu/abs/1986AJ.....91..204J/abstract |journal=The Astronomical Journal |language=en |volume=91 |pages=204–216 |doi=10.1086/114001 |bibcode=1986AJ.....91..204J |issn=0004-6256}}</ref>
NGC 4556 is host to a [[supermassive black hole]] with an estimated mass of 1.1 × 10<sup>9</sup> [[Solar mass|<var>M</var><sub>☉</sub>]].<ref>{{Cite journal |last1=Arzoumanian |first1=Zaven |last2=Baker |first2=Paul T. |last3=Brazier |first3=Adam |last4=Brook |first4=Paul R. |last5=Burke-Spolaor |first5=Sarah |last6=Becsy |first6=Bence |last7=Charisi |first7=Maria |last8=Chatterjee |first8=Shami |last9=Cordes |first9=James M. |last10=Cornish |first10=Neil J. |last11=Crawford |first11=Fronefield |last12=Cromartie |first12=H. Thankful |last13=Decesar |first13=Megan E. |last14=Demorest |first14=Paul B. |last15=Dolch |first15=Timothy |date=2021-06-01 |title=The NANOGrav 11 yr Data Set: Limits on Supermassive Black Hole Binaries in Galaxies within 500 Mpc |journal=The Astrophysical Journal |volume=914 |issue=2 |pages=121 |arxiv=2101.02716 |bibcode=2021ApJ...914..121A |doi=10.3847/1538-4357/abfcd3 |issn=0004-637X |doi-access=free}}</ref> == See also == * [[Coma Supercluster]] == References == {{Reflist}} == External links == {{NGC objects:4500-4999}} [[Category:Coma Berenices]] [[Category:NGC objects|4556]] [[Category:UGC objects|7765]] [[Category:Elliptical galaxies]] [[Category:Principal Galaxies Catalogue objects|041980]] [[Category:Astronomical objects discovered in 1785]] [[Category:NGC 4555 Group]]