Messier 93
Open cluster in the constellation Puppis
title: "Messier 93" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["open-clusters", "orion–cygnus-arm", "puppis", "messier-objects", "ngc-objects", "astronomical-objects-discovered-in-1781", "discoveries-by-charles-messier"] description: "Open cluster in the constellation Puppis" topic_path: "general/open-clusters" source: "https://en.wikipedia.org/wiki/Messier_93" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Open cluster in the constellation Puppis ::
::data[format=table title="Infobox open cluster"]
| Field | Value |
|---|---|
| image | [[Image:M93 Eguivar.jpg |
| caption | Open cluster Messier 93 in Puppis |
| name | Messier 93 |
| epoch | J2000.0 |
| constellation | Puppis |
| ra | |
| dec | |
| dist_ly | 1.037 kpc |
| appmag_v | 6.0 |
| size_v | 10′ |
| mass_msol | 723 |
| radius_ly | 10 ly |
| age | 387.3 Myr |
| names | NGC 2447, Cr 160, OCl 649.0 |
| :: |
| image = [[Image:M93 Eguivar.jpg|300px]] | caption = Open cluster Messier 93 in Puppis | name = Messier 93 | epoch = J2000.0 | constellation = Puppis | ra = | dec = | dist_ly = 1.037 kpc | appmag_v = 6.0 | size_v = 10′ | mass_msol = 723 | radius_ly = 10 ly | age = 387.3 Myr | notes = | names = NGC 2447, Cr 160, OCl 649.0
Messier 93 or M93, also known as NGC 2447 or the Critter Cluster, is an open cluster in the modestly southern constellation Puppis, the imagined poop deck of the legendary Argo.
Observational history and appearance
It was discovered by Charles Messier then added to his catalogue of comet-like objects in 1781. Caroline Herschel, the younger sister of William Herschel, independently discovered it in 1783, thinking it had not yet been catalogued by Messier.
Walter Scott Houston (died 1993) described its appearance: ::quote Some observers mention the cluster as having the shape of a starfish. With a fair-sized telescope, this is its appearance on a dull night, but [a four-inch refractor] shows it as a typical star-studded galactic cluster. ::
Properties
It has a Trumpler class of I 3 r, indicating it is strongly concentrated (I) with a large range in brightness (3) and is rich in stars (r).
M93 is about 3,380 light-years from the solar radius and has a great spatial radius of 10 light-years, a tidal radius of , and a core radius of 1.3 pc. Its age is estimated at 387.3 million years. It is nearly on the galactic plane and has an orbit that varies between 8.5 – from the Galactic Center over a period of Myr.
Fifty-four variable stars have been found in M93, including one slowly pulsating B-type star, one rotating ellipsoidal variable, seven Delta Scuti variables, six Gamma Doradus variables, and one hybrid δ Sct/γ Dor pulsator. Four spectroscopic binary systems within include a yellow straggler component.
Gallery
Image:Messier object 093.jpg|Messier 93 atlas image Image:M93map.png|Finder chart for M93
References
| title=Photoelectric Search for Peculiar Stars in Open Clusters - Part Fourteen - NGC1901 NGC2169 NGC2343 CR:132 NGC2423 and NGC2447 | last1=Maitzen | first1=H. M. | journal=Astronomy and Astrophysics Supplement | volume=102 | issue=1 | page=1 | date=November 1993 | bibcode=1993A&AS..102....1M | postscript=. }}
| first1=Hartmut | last1=Frommert | first2=Christine | last2=Kronberg | title=Messier 93 | work=SEDS Messier pages | publisher=Students for the Exploration and Development of Space (SEDS) | date=September 2, 2007 | url=http://www.messier.seds.org/m/m093.html | access-date=2018-12-07 | postscript=. }}
| last = Houston | first = Walter Scott | author-link=Walter Scott Houston | title = Deep-Sky Wonders | publisher = Sky Publishing Corporation | year = 2005 | isbn = 978-1-931559-23-2}}
| last1=Wu | first1 = Zhen-Yu | last2=Zhou | first2 = Xu | last3=Ma | first3 = Jun | last4=Du | first4 = Cui-Hua | title=The orbits of open clusters in the Galaxy | journal=Monthly Notices of the Royal Astronomical Society | volume=399 | issue=4 | pages=2146–2164 | date=November 2009 | arxiv=0909.3737 | bibcode=2009MNRAS.399.2146W | doi=10.1111/j.1365-2966.2009.15416.x | doi-access=free | s2cid=6066790 | postscript=. }}
| contribution=Time resolved surveys of stellar clusters | last1=Eyer | first1=L. | last2=Eggenberger | first2=P. | last3=Greco | first3=C. | last4=Saesen | first4=S. | last5=Anderson | first5=R. I. | last6=Mowlavi | first6=N. | title=JENAM 2010, Joint European and National Astronomy Meeting held 6-10 September, 2010 in Lisbon Portugal | pages=212 | date=September 2010 | arxiv=1011.4952 | id=212 | bibcode=2010jena.confE.212E | postscript=. }}
| title=Red giants and yellow stragglers in the young open cluster NGC 2447 | last1=da Silveira | first1=M. D. | last2=Pereira | first2=C. B. | last3=Drake | first3=N. A. | display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society | volume=476 | issue=4 | pages=4907–4931 | date=June 2018 | doi=10.1093/mnras/sty265 | doi-access=free | bibcode=2018MNRAS.476.4907D }}
| title=Concise Catalog of Deep-Sky Objects: Astrophysical Information for 550 Galaxies, Clusters and Nebulae | series=The Patrick Moore Practical Astronomy Series | first1=Warren H. | last1=Finlay | edition=2nd | publisher=Springer | year=2014 | isbn=978-3319031705 | page=120 | bibcode=2014ccds.book.....F | url=https://books.google.com/books?id=eJDIAwAAQBAJ&pg=PA120 }}
| display-authors=1 | last1=Piskunov | first1=A. E. | last2=Schilbach | first2=E. | last3=Kharchenko | first3=N. V. | last4=Röser | first4=S. | last5=Scholz | first5=R.-D. | title=Tidal radii and masses of open clusters | journal=Astronomy and Astrophysics | postscript=. | volume=477 | issue=1 | pages=165–172 | date=January 2008 | doi=10.1051/0004-6361:20078525 | bibcode=2008A&A...477..165P | doi-access=free }}
| title=Towards absolute scales for the radii and masses of open clusters | last1=Piskunov | first1=A. E. | last2=Schilbach | first2=E. | last3=Kharchenko | first3=N. V. | last4=Röser | first4=S. | last5=Scholz | first5=R. -D. | display-authors=1 | journal=Astronomy and Astrophysics | postscript=. | volume=468 | issue=1 | pages=151–161 | date=June 2007 | doi=10.1051/0004-6361:20077073 | bibcode=2007A&A...468..151P | arxiv=astro-ph/0702517 | s2cid=14769639 }}
| title=Gazing at the starry heavens | first1=Michael | last1=Hoskin | journal=Astronomy & Geophysics | volume=57 | issue=1 | date=February 1, 2016 | pages=1.22–1.25 | doi=10.1093/astrogeo/atw038 | bibcode=2016A&G....57a1.22H | doi-access=free }}
References
- "Messier 93".
- "NGC 2447".
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