Messier 71

---

title: "Messier 71" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["globular-clusters", "sagitta", "messier-objects", "ngc-objects", "astronomical-objects-discovered-in-1745"] description: "Globular cluster in the constellation Sagitta" topic_path: "general/globular-clusters" source: "https://en.wikipedia.org/wiki/Messier_71" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Globular cluster in the constellation Sagitta ::

::data[format=table title="Infobox globular cluster"]

Field	Value
name	Messier 71
image	Messier 71, an Unusual Globular Cluster.jpg
caption	The globular cluster Messier 71 by the Hubble Space Telescope.
epoch	J2000
class	X-XI
constellation	Sagitta
ra
dec
dist_ly	13.0 kly
appmag_v	8.2
size_v	7.2'
mass_msol
radius_ly	13 ly
metal_fe	–0.78
age	9-10 Gyr
names	M71, NGC 6838, Cr 409, GCl 115
::

| name = Messier 71 | image = Messier 71, an Unusual Globular Cluster.jpg | caption = The globular cluster Messier 71 by the Hubble Space Telescope. | credit = | epoch = J2000 | class = X-XI | constellation = Sagitta | ra = | dec = | dist_ly = 13.0 kly | appmag_v = 8.2 | size_v = 7.2' | mass_msol = | radius_ly = 13 ly | metal_fe = –0.78 | v_hb = | age = 9-10 Gyr | notes = | names = M71, NGC 6838, Cr 409, GCl 115

Messier 71 (also known as M71, NGC 6838, or the Angelfish Cluster) is a globular cluster in the small northern constellation Sagitta. It was discovered by Philippe Loys de Chéseaux in 1745 and included by Charles Messier in his catalog of non-comet-like objects in 1780. It was also noted by Koehler at Dresden around 1775. Messier 71 is also known as NGC 6839, though this identification is very uncertain.

This star cluster is about 13,000 light years away from Earth and spans 27 ly. The irregular variable star Z Sagittae is a member.

::figure[src="https://upload.wikimedia.org/wikipedia/commons/a/a8/M71_Crop.png" caption="luminosity]] of around 19,000 {{lo"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/c/c5/M71map.png" caption="Map showing location of M71"] ::

References

Gallery

File:M71.jpg|Till Credner and Sven Kohle, Calar Alto Observatory. File:M71 - Noao-m71.jpg|M71 in visible light by the NOAO. File:NGC 6838 2MASS.jpg|M71 in infrared by the survey 2MASS. File:NGC 6838 DSS.jpg|M71 in visible light by the survey DSS.

References

1. "Messier 71".
2. distance × sin( diameter_angle / 2 ) = 13 ly. radius
3. "New General Catalog Objects: NGC 6800 - 6849".
4. "Your NED Search Results".
5. (December 2010). "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters". The Astronomical Journal.
6. (August 2010). "Initial conditions for globular clusters and assembly of the old globular cluster population of the Milky Way". [[Monthly Notices of the Royal Astronomical Society]].
7. "M 71".
8. (November 2007). "A 1.4 GHz Arecibo Survey for Pulsars in Globular Clusters". The Astrophysical Journal.
9. (November 2011). "Young Radio Pulsars in Galactic Globular Clusters". The Astrophysical Journal.
10. "Z Sge". AAVSO.
11. (March 2020). "The WAGGS project-III. Discrepant mass-to-light ratios of Galactic globular clusters at high metallicity". Monthly Notices of the Royal Astronomical Society.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::