View source for Messier 48

{{Short description|Open cluster in the constellation Hydra}}
{{Use dmy dates|date=March 2021}}
{{Infobox open cluster
 | name = [[Messier object|Messier]] 48
 | image = [[File:M48 Mazur.jpg|300px]]
 | caption = Open cluster Messier 48 in Hydra
 | epoch = [[J2000]]
 | class =
 | ra  = {{RA|08|13|43.0}}<ref name=Wu2009a/>
 | dec = {{Dec|-05|45|00}}<ref name=Wu2009a/>
 | constellation = [[Hydra (constellation)|Hydra]]
 | dist_ly   = {{Convert|770|pc|ly|order=flip|abbr=on|lk=on}}<ref name=Wu2009a/>
 | appmag_v  = 5.8<ref name=Mullaney2007/><ref name=Inglis2011/>
 | size_v    = {{Val|30|ul=arcminute}}<ref name=Mullaney2007/>
 | mass_msol = {{Val|2366|1109|755|fmt=commas}}<ref name=Piskunov2008/>
 | radius_ly = {{Val|63|u=ly}}<ref name=Piskunov2008/>
 | age = {{Val|450|50}}&nbsp;Myr<ref name=Barnes2015/>
 | notes =
 | names = M48, [[New General Catalogue|NGC]] 2548,<ref name=SIMBAD/> [[Collinder catalogue|Cr]] 179, H IV-22
}}

'''Messier 48''' or '''M48''', also known as '''NGC 2548''', is an [[open cluster]] of stars in the [[celestial equator|equatorial]] [[constellation]] of [[Hydra (constellation)|Hydra]]. It sits near Hydra's westernmost limit with [[Monoceros]],<ref name=Sinnott_Perryman_1997/> about {{DEC|18|34}} to the east and slightly south of Hydra's brightest star, [[Alphard]].<ref name=Adam2018/> This grouping was discovered by [[Charles Messier]] in 1771, but there is no cluster precisely where Messier indicated; he made an error, as he did with M47. The value that he gave for the [[right ascension]] matches, however, his [[declination]] is off by five degrees.<ref name=WSH/> Credit for discovery is sometimes given instead to [[Caroline Herschel]] in 1783.<ref name=WSH/> Her nephew [[John Herschel]] described it as, "a superb cluster which fills the whole field; stars of 9th and 10th to the 13th magnitude &ndash; and none below, but the whole ground of the sky on which it stands is singularly dotted over with infinitely minute points".<ref name=Adam2018/>

M48 is visible to the [[naked eye]] under good atmospheric conditions. The brightest member is the star HIP 40348 at visual magnitude 8.3.<ref name=Adam2018/> The cluster is located some {{Convert|770|pc|ly|disp=out|order=flip|abbr=off}} from the Sun.<ref name=Wu2009a/> The age estimated from [[Stellar isochrone|isochrone]]s is {{Val|400|100}}&nbsp;Myr, while [[gyrochronology]] age estimate is {{Val|450|50}}&nbsp;Myr &ndash; in good agreement.<ref name=Barnes2015/> This makes it intermediate in age between the [[Pleiades]], at around 100&nbsp;Myr, and the [[Hyades (star cluster)|Hyades]], at about&nbsp;650 Myr. The [[metallicity]] of the cluster, based on the abundance of iron (Fe), is [Fe/H] = {{val|−0.063|0.007|ul=Metallicity#Chemical abundance ratios{{!}}dex}}, where &minus;1 would be ten times lower than in the Sun. It is more metal-poor than the Pleiades, Hyades, and [[Praesepe]] clusters.<ref name=Sun_et_al_2020/>

The cluster has a [[tidal radius (cluster)|tidal radius]] of {{Convert|19.4|±|2.4|pc|ly|order=flip|abbr=on}}<ref name=Piskunov2008/> with at least 438<ref name=Vicente2016/> members and a mass of {{Val|2366|ul=solar mass|fmt=commas}}.<ref name=Piskunov2008/> The general structure of the cluster is fragmented and lumpy, which may be due to interactions with the [[galactic disk]]. The cluster is now subdivided into three groups, each of which has its own collective [[proper motion]].<ref name=Vicente2016/>

==See also==
* [[List of Messier objects]]

==References==
{{reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=M 48 | access-date=26 November 2018 }}</ref>

<ref name=Sinnott_Perryman_1997>{{citation | postscript=.
 | first1=Roger W. | last1=Sinnott
 | first2=Michael A. C. | last2=Perryman
 | title=Millennium Star Atlas | page=810
 | volume=2 | year=1997 | isbn=0-933346-83-2
 | publisher=Sky Publishing Corporation and the European Space Agency }}</ref>

<ref name=Sun_et_al_2020>{{citation
 | title=WIYN Open Cluster Study LXXIX. M48 (NGC 2548) I. Radial Velocities, Rotational Velocities, and Metallicities of Stars in the Open Cluster M48 (NGC 2548)
 | display-authors=1 | last1=Sun | first1=Qinghui
 | last2=Deliyannis | first2=Constantine P. | last3=Steinhauer | first3=Aaron
 | last4=Twarog | first4=Bruce A. | last5=Anthony-Twarog | first5=Barbara J.
 | journal=The Astronomical Journal | postscript=.
 | volume=159 | issue=5 | id=220 | pages=13 | date=May 2020
 | arxiv=2004.06812 | bibcode=2020AJ....159..220S 
 | doi=10.3847/1538-3881/ab83ef | s2cid=215769094 | doi-access=free }}</ref>

<ref name=Barnes2015>{{citation
 | title=A color-period diagram for the open cluster M 48 (NGC 2548), and its rotational age
 | last1=Barnes | first1=Sydney A. | last2=Weingrill | first2=Joerg
 | last3=Granzer | first3=Thomas | last4=Spada | first4=Federico
 | last5=Strassmeier | first5=Klaus G. | display-authors=1
 | journal=Astronomy & Astrophysics
 | volume=583 | id=A73 | pages=21 | date=November 2015
 | doi=10.1051/0004-6361/201526129 | postscript=.
 | bibcode=2015A&A...583A..73B | arxiv=1511.00554 | s2cid=118822665 }}</ref>

<ref name=Adam2018>{{citation
 | 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=227 | postscript=.
 | url=https://books.google.com/books?id=7nNUDwAAQBAJ&pg=PA227 | bibcode=2018imor.book.....A
 }}</ref>

<ref name=Vicente2016>{{citation
 | title=NGC 2548: clumpy spatial and kinematic structure in an intermediate-age Galactic cluster
 | last1=Vicente | first1=Belén | last2=Sánchez | first2=Néstor
 | last3=Alfaro | first3=Emilio J. | display-authors=1
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=461 | issue=3 | pages=2519–2526 | date=September 2016
 | doi=10.1093/mnras/stw1487 | doi-access=free | arxiv=1606.06044
 | bibcode=2016MNRAS.461.2519V | postscript=. }}</ref>

<ref name=Mullaney2007>{{citation
 | title=The Herschel Objects and How to Observe Them
 | series=Astronomers' Observing Guides
 | first1=James | last1=Mullaney | postscript=.
 | publisher=Springer Science & Business Media
 | year=2007 | isbn=978-0387681252 | page=93
 | url=https://books.google.com/books?id=HFg2sOjrFtsC&pg=PA93 | bibcode=2007hoho.book.....M
 }}</ref>

<ref name=WSH>{{citation
 | last=Houston | first=Walter Scott
 | author-link=Walter Scott Houston
 | title=Deep-Sky Wonders | postscript=.
 | publisher=Sky Publishing Corporation
 | year=2005 | isbn=978-1-931559-23-2 }}</ref>

<ref name=Wu2009a>{{citation | display-authors=1
 | 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=. }}</ref>

<ref name=Piskunov2008>{{citation
 | 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
 | title=Tidal radii and masses of open clusters
 | journal=Astronomy and Astrophysics
 | volume=477 | issue=1 | pages=165–172
 | date=January 2008 | doi=10.1051/0004-6361:20078525
 | bibcode=2008A&A...477..165P | postscript=. | doi-access=free }}</ref>

<ref name=Inglis2011>{{citation
 | title=A Field Guide to Deep-Sky Objects
 | first=Mike | last=Inglis | date=2011
 | page=110 | isbn=9781461412663
 | publisher=Springer New York | postscript=.
 | url=https://books.google.com/books?id=ZM_K3XlND-0C&pg=PA110 }}</ref>

}}

==External links==
{{commons category|Messier 48}}
* [http://messier.seds.org/m/m048.html Messier 48, SEDS Messier pages]
* {{WikiSky}}

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{{Messier objects}}
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{{Hydra (constellation)}}
{{Sky|08|13.7|00|-|05|45|00|1500}}

{{DEFAULTSORT:Messier 48}}
[[Category:Open clusters|Messier 048]]
[[Category:Orion–Cygnus Arm]]
[[Category:Hydra (constellation)|Messier 048]]
[[Category:Messier objects|048]]
[[Category:NGC objects|Messier 048]]
[[Category:Astronomical objects discovered in 1771|17710219]]
[[Category:Discoveries by Charles Messier]]