Editing Corona Borealis (section)

=== Deep-sky objects ===
[[File:Abell2142 chandra xray.jpg|thumb|left|upright|X-ray image of galaxy cluster [[Abell 2142]]]]
Corona Borealis contains few galaxies observable with amateur telescopes.<ref>{{cite book|last=Luginbuhl|first=Christian B. |author2=Skiff, Brian A. |title=Observing Handbook and Catalogue of Deep-Sky Objects|publisher=Cambridge University Press|location=Cambridge, United Kingdom|date=1998|pages=92|isbn=978-0-521-62556-2|url=https://books.google.com/books?id=MwCyjQpGU7UC&pg=PA92}}</ref> [[NGC 6085]] and [[NGC 6086|6086]] are a faint [[spiral galaxy|spiral]] and [[elliptical galaxy]] respectively close enough to each other to be seen in the same visual field through a telescope.<ref name="Rumistrzewicz">{{cite book|last=Rumistrzewicz|first=Stefan |title=A Visual Astronomer's Photographic Guide to the Deep Sky: A Pocket Field Guide|publisher=Springer Science & Business Media|location=New York, New York|date=2010|pages=158|isbn=978-1-4419-7242-2|url=https://books.google.com/books?id=Vhjn3DEJpyIC&pg=PA158}}</ref> [[Abell 2142]] is a huge (six million light-year diameter), [[X-ray]] luminous [[galaxy cluster]] that is the result of an ongoing merger between two galaxy clusters. It has a [[redshift]] of 0.0909 (meaning it is moving away from us at 27,250&nbsp;km/s) and a visual magnitude of 16.0. It is about 1.2 [[1,000,000,000 (number)|billion]] light-years away.{{efn|1=Distance calculated from redshift.}}<ref name="NED">{{cite web | title= NASA/IPAC Extragalactic Database  | work= Results for Abell 2142  | url= http://nedwww.ipac.caltech.edu/ | access-date = 11 Nov 2008 | archive-url= https://web.archive.org/web/20081216032441/http://nedwww.ipac.caltech.edu/| archive-date= 16 December 2008 | url-status= live}}</ref> Another galaxy cluster in the constellation, [[RX J1532.9+3021|RX&nbsp;J1532.9+3021]], is approximately 3.9 billion [[light-year]]s from Earth.<ref name="chandra">{{cite web | url =http://chandra.harvard.edu/photo/2014/rxj1532/| title =RX J1532.9+3021: Extreme Power of Black Hole Revealed |publisher =Chandra X-ray Center|date=January 23, 2014| access-date =27 January 2014 }}</ref> At the cluster's center is a large elliptical galaxy containing one of the [[List of most massive black holes|most massive]] and most powerful [[supermassive black hole]]s yet discovered.<ref name="chandra"/>  [[Abell 2065]] is a highly concentrated galaxy cluster containing more than 400 members, the brightest of which are 16th magnitude; the cluster is more than one billion light-years from Earth.{{sfn|Ridpath|Tirion|2001|pp=126–128}} On a larger scale still, Abell&nbsp;2065, along with [[Abell 2061]], [[Abell 2067]], [[Abell 2079]], [[Abell 2089]], and [[Abell 2092]], make up the [[Corona Borealis Supercluster]].<ref name=postman88>{{cite journal |title=The dynamics of the Corona Borealis supercluster |author1=Postman, M. |author2=Geller, M. J. |author3=Huchra, J. P. |journal=Astronomical Journal | volume= 95 |year= 1988 |pages= 267–83 |doi=10.1086/114635 |bibcode=1988AJ.....95..267P}}</ref> Another galaxy cluster, [[Abell 2162]], is a member of the [[Hercules Superclusters]].<ref name=kopylova>{{cite journal|author1=Kopylova, F. G. |author2=Kopylov, A. I. |date=2013|title=Investigation of properties of galaxy clusters in the Hercules supercluster region|journal=Astronomy Letters|volume=39|issue=1|pages=1–16|doi=10.1134/S1063773712120043 | bibcode= 2013AstL...39....1K |s2cid=120136802 }}</ref>{{Clear}}