Editing Messier 4 (section)

{{short description|Globular cluster in Scorpius}}
{{Infobox globular cluster
| name = Messier 4
| image = [[File:Globular star cluster Messier 4.jpg|280px]]
| caption = Globular star cluster Messier 4
| credit = 
| epoch = [[J2000]]
| class = IX<ref name=hcob849_11/>
| constellation = [[Scorpius]]
| ra = {{RA|16|23|35.22}}<ref name=aj140_6_1830/>
| dec = {{DEC|−26|31|32.7}}<ref name=aj140_6_1830/>
| dist_ly = {{Convert|6.033|kly|kpc|abbr=on|lk=on}}<ref>{{cite journal|last=Baumgardt|first=H.|display-authors=etal|title=Accurate distances to Galactic globular clusters through a combination of Gaia EDR3, HST, and literature data|journal=Monthly Notices of the Royal Astronomical Society|date=2021|volume=505|issue=4 |pages=5957–5977|doi=10.1093/mnras/stab1474|doi-access=free |arxiv =2105.09526 |bibcode = 2021MNRAS.505.5957B}}</ref>
| appmag_v = 5.6<ref>{{cite web |url=http://www.messier.seds.org/m/m004.html |title=Messier 4 |access-date=21 July 2024 |website=SEDS Messier Catalog}}</ref>
| size_v = 26′.0
| mass_msol = {{Val|8.4|e=4}}<ref name="Vitral+23">{{cite journal|last=Vitral|first=E.|display-authors=etal|title=An elusive dark central mass in the globular cluster M4|journal=Monthly Notices of the Royal Astronomical Society|date=2023|volume=522|issue=4 |pages=5740–5757|doi=10.1093/mnras/stad1068|doi-access=free |arxiv =2305.12702 |bibcode = 2023MNRAS.522.5740V }}</ref>
| radius_ly = 35 [[light-year]]s {{Citation needed|reason=Did not specify which radius it is (half-mass / core / tidal), and cannot find source. |date=September 2021}}
| v_hb =
| age = {{nowrap|(12.2 ± 0.2) [[Byr|Gyr]]}}<ref name=aaa143_1/>
| metal_fe = −1.07<ref name=aaa490_2/>
| notes = Closest [[globular cluster]]
| names = [[New General Catalogue|NGC]] 6121<ref name="simbad"/>
}}

'''Messier 4''' or '''M4''' (also known as '''NGC 6121''' or the '''Spider Globular Cluster''') is a [[globular cluster]] in the [[constellation]] of [[Scorpius]]. It was discovered by [[Philippe Loys de Chéseaux]] in 1745 and catalogued by [[Charles Messier]] in 1764.<ref name=":0">{{Cite web |title=Messier Object 4 |url=http://www.messier.seds.org/m/m004.html |access-date=2023-11-13 |website=www.messier.seds.org}}</ref> It was the first globular cluster in which individual [[star]]s were resolved.<ref name=":0" />