编辑“︁NGC 6397”︁（章节）

=== 黑洞 ===
在2021年2月據報導，根據哈伯太空望遠鏡和歐洲航天局[[蓋亞任務]]收集的數據得出核心附近恒星的運動：NGC 6397的核心含有相對密集的緻密天體（[[白矮星]]、[[中子星]]和[[黑洞]]）<ref name="VitralMamon21">{{Citation | last1=Vitral | first1=Eduardo | title=Does NGC 6397 contain an intermediate-mass black hole or a more diffuse inner subcluster? | last2=Mamon | first2=Gary A. | doi=10.1051/0004-6361/202039650 | date=2021 | journal=A&A | volume=646 | issue=A63 | pages=A63 |bibcode = 2021A&A...646A..63V | doi-access=free }}</ref><ref>{{cite news|date=11 February 2021|title=Hubble Uncovers Concentration of Small Black Holes|url=https://esahubble.org/news/heic2103/|work=ESA|access-date=21 February 2021|archive-date=2021-04-27|archive-url=https://web.archive.org/web/20210427140754/https://esahubble.org/news/heic2103/}}</ref>。這個中心區域的黑洞總質量上限約為1,000個太陽質量，來自許多顆，估計平均大小為20個太陽質量的較小黑洞<ref name="NYT-20210226">{{cite news |last=Overbye |first=Dennis |authorlink=Dennis Overbye |title=Hunting for a Giant Black Hole, Astronomers Found a Nest of Darkness - No Gargantua dwells at the heart of stellar cluster NGC 6397. Instead, a few dozen smaller black holes seem to be swarming around in there, throwing their considerable masses around. |url=https://www.nytimes.com/2021/02/26/science/astronomy-black-hole-ngc6397.html |date=26 February 2021 |work=[[The New York Times]] |access-date=27 February 2021 |archive-date=2021-07-28 |archive-url=https://web.archive.org/web/20210728112403/https://www.nytimes.com/2021/02/26/science/astronomy-black-hole-ngc6397.html }}</ref>。然而，也有人認為，由於動力相互作用，這些黑洞中的許多都會從星團核心噴出，這導致這種看不見的濃縮物主要由白矮星和中子星組成，只有極少數的黑洞<ref>{{Citation | last1=Weatherford | first1=Newlin C. |title=A Dynamical Survey of Stellar-mass Black Holes in 50 Milky Way Globular Clusters| last2=Sourav | first2=Chatterjee | last3=Kremer | first3=Kyle | last4=Rasio | first4=Frederic A. | doi=10.3847/1538-4357/ab9f98 | date=2020 | journal=  The Astrophysical Journal| volume=898 | issue=162 | page=162 | bibcode = 2020ApJ...898..162W | arxiv=1911.09125 | s2cid=208202116 }}</ref>。