Messier 70
Globular cluster in the constellation Sagittarius
title: "Messier 70" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["globular-clusters", "sagittarius-(constellation)", "messier-objects", "ngc-objects", "astronomical-objects-discovered-in-1780", "discoveries-by-charles-messier"] description: "Globular cluster in the constellation Sagittarius" topic_path: "general/globular-clusters" source: "https://en.wikipedia.org/wiki/Messier_70" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Globular cluster in the constellation Sagittarius ::
::data[format=table title="Infobox globular cluster"]
| Field | Value |
|---|---|
| name | Messier 70 |
| image | [[Image:Messier70-HST-Potw1215a.jpg |
| caption | Globular cluster Messier 70 by Hubble Space Telescope; 3.3 view |
| epoch | J2000 |
| class | V |
| constellation | Sagittarius |
| ra | |
| dec | |
| dist_ly | 29.4 kly |
| appmag_v | 7.9 |
| size_v | |
| mass_msol | |
| radius_ly | 34 ly |
| radius_tidal_arcminsec | |
| metal_fe | –1.35 |
| age | 12.80 Gyr |
| names | GCl 101, M70, NGC 6681 |
| :: |
| name = Messier 70 | image = [[Image:Messier70-HST-Potw1215a.jpg|300px]] | caption = Globular cluster Messier 70 by Hubble Space Telescope; 3.3 view | credit = | epoch = J2000 | class = V | constellation = Sagittarius | ra = | dec = | dist_ly = 29.4 kly | appmag_v = 7.9 | size_v = | mass_msol = | radius_ly = 34 ly | radius_tidal_arcminsec = | metal_fe = –1.35 | age = 12.80 Gyr | notes = | names = GCl 101, M70, NGC 6681
Messier 70 or M70, also known as NGC 6681, is a globular cluster of stars to be found in the south of Sagittarius. It was discovered by Charles Messier in 1780. The famous comet Hale–Bopp was discovered near this cluster in 1995.
It is about 29,400 light years away from Earth and around 2 kpc from the Galactic Center. It is roughly the same size and luminosity as its neighbour in space, M69. M70 has a very small core radius of 0.068 pc and a half-light radius of 55.80 pc. This cluster has undergone core collapse, leaving it centrally concentrated with the luminosity distribution following a power law.
There are two distinct stellar populations in the cluster, with each displaying unique abundances. These likely represent different generations of stars. Five known variable stars lie within its broadest radius, the tidal radius, all of which are RR Lyrae variables. The cluster may have two blue stragglers near the core.
Gallery
File:Messier 70 Hubble WikiSky.jpg|Image by Hubble Space Telescope File:M70map.png|Map showing M70, against a conventional (southern) horizon
References and footnotes
| title=It Came From Outer Space Wearing an RAF Blazer!: A Fan's Biography of Sir Patrick Moore | first1=Martin | last1=Mobberley | publisher=Springer Science & Business Media | year=2013 | isbn=978-3319006093 | page=483 | url=https://books.google.com/books?id=dfO7BAAAQBAJ&pg=PA483 }}
| first1=Hartmut | last1=Frommert | first2=Christine | last2=Kronberg | title=Globular Cluster M70 | date=30 August 2007 | work=SEDS Messier pages | publisher=Students for the Exploration and Development of Space (SEDS) | url=http://messier.seds.org/m/m070.html | access-date=2018-12-04 | postscript=. }}
| title=Imaging the Messier Objects Remotely from Your Laptop | series=The Patrick Moore Practical Astronomy Series | first1=Len | last1=Adam | publisher=Springer | year=2018 | isbn=978-3319653853 | page=304 | url=https://books.google.com/books?id=7nNUDwAAQBAJ&pg=PA304 | bibcode=2018imor.book.....A
| contribution=Physical Parameters of Galactic Globular Clusters | last1=Djorgovski | first1=S. | title=Structure and Dynamics of Globular Clusters. Proceedings of a Workshop held in Berkeley, California, July 15–17, 1992, to Honor the 65th Birthday of Ivan King | editor1-first=S. G. | editor1-last=Djorgovski | editor2-first=G. | editor2-last=Meylan | publisher=Astronomical Society of the Pacific | volume=50 | pages=373 | location=San Francisco, California | date=January 1993 | isbn=978-0937707692 | bibcode=1993ASPC...50..373D | postscript=. }}
| title=Mass-to-light ratios for globular clusters. I - The centrally concentrated clusters NGC 6624, M28 (NGC 6626), and M70 (NGC 6681) | last1=Pryor | first1=Carlton | last2=McClure | first2=Robert D. | last3=Fletcher | first3=J. M. | last4=Hesser | first4=James E. | display-authors=1 | postscript=. | journal=Astronomical Journal | volume=98 | date=August 1989 | pages=596–610 | doi=10.1086/115160 | bibcode=1989AJ.....98..596P }}
| display-authors=1 | postscript=. | title=Far-ultraviolet imaging of the globular cluster NGC 6681 with WFPC2 | last1=Watson | first1=Alan M. | last2=Mould | first2=Jeremy R. | last3=Gallagher | first3=John S., III | last4=Ballester | first4=Gilda E. | last5=Burrows | first5=Christopher J. | last6=Casertano | first6=Stefano | last7=Clarke | first7=John T. | last8=Crisp | first8=David | last9=Griffiths | first9=Richard E. | last10=Hester | first10=J. Jeff | last11=Hoessel | first11=John G. | last12=Holtzman | first12=Jon A. | last13=Scowen | first13=Paul A. | last14=Stapelfeldt | first14=Karl R. | last15=Trauger | first15=John T. | last16=Westphal | first16=James A. | journal=Astrophysical Journal, Part 2 | volume=435 | issue=1 | pages=L55–L58 | date=November 1994 | doi=10.1086/187593 | bibcode=1994ApJ...435L..55W | url=https://authors.library.caltech.edu/53635/1/1994ApJ___435L__55W.pdf
| title=The variable stars in the field of the globular cluster NGC 6681 | last1=Liller | first1=M. H. | journal=Astronomical Journal | postscript=. | volume=88 | date=October 1983 | pages=1463–1469 | doi=10.1086/113435 | bibcode=1983AJ.....88.1463L }}
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| title=High-resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6681 | last1=O'Malley | first1=Erin M. | last2=Knaizev | first2=Alexei | last3=McWilliam | first3=Andrew | last4=Chaboyer | first4=Brian | journal=The Astrophysical Journal | display-authors=1 | volume=846 | issue=1 | id=23 | pages=15 | date=September 2017 | doi=10.3847/1538-4357/aa7b72 | postscript=. | bibcode=2017ApJ...846...23O | arxiv=1706.06962 | s2cid=118972140 | doi-access=free }}
| title=Uniting old stellar systems: from globular clusters to giant ellipticals | last1=Forbes | first1=Duncan A. | last2=Lasky | first2=Paul | last3=Graham | first3=Alister W. | last4=Spitler | first4=Lee | display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=4 | pages=1924–1936 | date=October 2008 | doi=10.1111/j.1365-2966.2008.13739.x | doi-access=free | postscript=. | bibcode=2008MNRAS.389.1924F | arxiv=0806.1090 | s2cid=14108457 }}
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| last1=Shapley | first1=Harlow | last2=Sawyer | first2=Helen B. | title=A Classification of Globular Clusters | journal=Harvard College Observatory Bulletin | volume=849 | issue=849 | pages=11–14 | date=August 1927 | bibcode=1927BHarO.849...11S | postscript=. }}
| last1=Forbes | first1=Duncan A. | last2=Bridges | first2=Terry | title=Accreted versus in situ Milky Way globular clusters | journal=Monthly Notices of the Royal Astronomical Society | volume=404 | issue=3 | pages=1203–1214 | date=May 2010 | doi=10.1111/j.1365-2966.2010.16373.x | doi-access=free | bibcode=2010MNRAS.404.1203F | postscript=. | arxiv=1001.4289 | s2cid=51825384 }}
| title=NGC 6681 | access-date=2006-11-17 }}
| last1=Boyles | first1=J. | last2=Lorimer | first2=D. R. | last3=Turk | first3=P. J. | last4=Mnatsakanov | first4=R. | last5=Lynch | first5=R. S. | last6=Ransom | first6=S. M. | last7=Freire | first7=P. C. | last8=Belczynski | first8=K. | title=Young Radio Pulsars in Galactic Globular Clusters | display-authors=1 | journal=The Astrophysical Journal | volume=742 | issue=1 | page=51 | date=November 2011 | doi=10.1088/0004-637X/742/1/51 | bibcode=2011ApJ...742...51B | postscript=. | arxiv=1108.4402 | s2cid=118649860 }}
References
- "Messier 70".
- distance × sin( diameter_angle / 2 ) = 34 ly. radius
::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. ::