Editing Beehive Cluster (section)

{{Short description|Open cluster in the constellation Cancer}}
{{about|the Beehive Cluster||Beehive}}
{{Infobox open cluster
| name = Messier 44 / Beehive Cluster
| image = M44-Star-Cluster.png
| image_size = 350px
| caption = The Beehive Cluster in Cancer constellation (north is to the right)
| epoch = J2000.0
| class = II,2,m
| constellation = [[Cancer (constellation)|Cancer]]
| ra = 08<sup>h</sup>&nbsp;40.4<sup>m</sup>
| dec = 19° 59′
| dist_ly = 610 ly<ref>{{Cite web|title=NGC 2632|url=http://simbad.u-strasbg.fr/simbad/sim-id?mescat.distance=on&Ident=%401110595&Name=NGC++2632&submit=display+selected+measurements#lab_meas|access-date=2020-06-11|website=sim-id}}</ref>
| dist_pc = 187 pc 
| appmag_v = 3.7<ref name="SEDS">
{{cite web
 |title=Messier 44
 |url=http://messier.seds.org/m/m044.html
 |work=[[SEDS]]
 |access-date=2009-12-10
}}</ref>
| size_v = 95′
| mass_kg = 
| mass_msol = ~500–600
| radius_pc = 3.5 pc
| v_hb = 
| age = ~600–700 million years
| names = Praesepe, M44, NGC 2632, [[Collinder catalogue|Cr]] 189
}}
[[File:Presepemap.png|thumb|Map showing the location of M44 in the constellation of Cancer]]
The '''Beehive Cluster''' (also known as '''Praesepe''' (Latin for "manger", "cot" or "crib"), '''M44''', '''NGC 2632''', or '''Cr 189'''), is an [[open cluster]] in the constellation [[Cancer (constellation)|Cancer]]. One of the nearest open clusters to [[Earth]], it contains a larger population of stars than other nearby bright open clusters holding around 1,000 [[Star|stars]]. Under dark skies, the Beehive Cluster looks like a small [[Nebula|nebulous]] object to the naked eye, and has been known since ancient times. Classical astronomer [[Ptolemy]] described it as a "nebulous mass in the breast of Cancer". It was among the first objects that [[Galileo]] studied with his
telescope.<ref name="Messier44">{{cite web |title=Messier 44: Observations and Descriptions |url=http://www.maa.clell.de/Messier/Mdes/dm044.html}}</ref>

Its age and proper motion coincide with those of the [[Hyades (star cluster)|Hyades]], suggesting they may share similar origins.<ref name="Klein-Wassink1927">
{{cite journal
|last=Klein-Wassink |first=W.J.
|date=1927
|title=The proper motion and the distance of the Praesepe cluster
|journal=Publications of the Kapteyn Astronomical Laboratory Groningen
|volume=41
|pages=1–48
|bibcode=1927PGro...41....1K
}}</ref><ref name="Dobbie2006">
{{cite journal
|author=Dobbie PD |author2=Napiwotzki R |author3=Burleigh MR |date=2006
|title=New Praesepe white dwarfs and the initial mass-final mass relation
|journal=[[Monthly Notices of the Royal Astronomical Society]]
|volume=369
|issue=1 |pages=383–389
|bibcode=2006MNRAS.369..383D
|doi=10.1111/j.1365-2966.2006.10311.x
|doi-access=free |arxiv=astro-ph/0603314 |s2cid=17914736 |display-authors=etal}}</ref> Both clusters also contain [[red giants]] and [[white dwarfs]], which represent later stages of stellar evolution, along with many [[main sequence]] stars.

The distance to M44 is often cited to be between 160 and 187 [[parsecs]] (520–610 [[light years]]),<ref name="Pinfield2003">
{{cite journal
 |author=Pinfield DJ
 |display-authors=4
 |author2=Dobbie PD
 |author3=Jameson F
 |author4=Steele IA
 |author5=Jones HRA
 |author6=Katsiyannis AC
 |date=2003
 |title=Brown dwarfs and low-mass stars in the Pleiades and Praesepe: Membership and binarity
 |journal=[[Monthly Notices of the Royal Astronomical Society]]
 |volume=342 |issue=4
 |pages=1241–1259
 |bibcode= 2003MNRAS.342.1241P
 |doi=10.1046/j.1365-8711.2003.06630.x
|doi-access=free
 |arxiv = astro-ph/0303600 |s2cid=285922
 }}</ref><ref name="Kraus2007">
{{cite journal
 |author=Kraus AL |author2=Hillenbrand LA
 |date=2007
 |title=The stellar populations of Praesepe and Coma Berenices
 |journal=[[Astronomical Journal]]
 |volume=134 |issue=6
 |pages=2340–2352
 |bibcode=2007AJ....134.2340K
 |doi=10.1086/522831
|arxiv = 0708.2719 |s2cid=15945900
 }}</ref><ref name="WEBDA">[http://www.univie.ac.at/webda/ WEBDA]</ref> but the revised [[Hipparcos]] parallaxes (2009) for Praesepe members and the latest infrared [[color-magnitude diagram]] favors an analogous distance of 182 pc.<ref name=vanleeuwen09>van Leeuwen, F. [http://adsabs.harvard.edu/abs/2009A%26A...497..209V "Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue"], ''A&A'', 2009</ref><ref name=majaess11>Majaess, D.; Turner, D.; Lane, D.; Krajci, T. [http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1102.1705 "Deep Infrared ZAMS Fits to Benchmark Open Clusters Hosting delta Scuti Stars"], ''Journal of the American Association of Variable Star Observers'', 2011</ref> There are better age estimates of around 600 million years<ref name="Dobbie2006"/><ref name="Kraus2007"/><ref name="Adams2002">
{{cite journal
|author=Adams JD |author2=Stauffer JR |author3=Skrutskie MF |date=2002
|title=Structure of the Praesepe Star Cluster
|journal=[[Astronomical Journal]]
|volume=124 |issue=3 |pages=1570–1584
|bibcode=2002AJ....124.1570A
|doi=10.1086/342016
|display-authors=etal|doi-access=free}}</ref> (compared to about 625 million years for the Hyades).<ref name="Perryman1998">
{{cite journal
|author=Perryman M
|author2=Brown A
|author3=Lebreton Y
|author4=Gomez A
|author5=Turon C
|author6=Cayrel de Strobel G
|author7=Mermilliod J
|author8=Robichon N
|author9=Kovalevsky J
|author10=Crifo F
|display-authors=6
|date=1998
|title=The Hyades: Distance, structure, dynamics, and age
|journal=[[Astronomy & Astrophysics]]
|volume=331 |pages=81–120
|bibcode=1998A&A...331...81P
|arxiv = astro-ph/9707253 }}</ref> The diameter of the bright inner cluster core is about 7.0 parsecs (23 light years).<ref name="Adams2002"/>

At 1.5° across, the cluster easily fits within the field of view of binoculars or low-powered small telescopes. [[Regulus]], [[Castor (star)|Castor]], and [[Pollux (star)|Pollux]] are [[guide star]]s.