Messier 107
Template:Short description Template:Infobox globular cluster
Messier 107 or M107, also known as NGC 6171 or the Crucifix Cluster, is a very loose globular cluster in a very mildly southern part of the sky close to the equator in Ophiuchus, and is the last such object in the Messier Catalogue.
Observational history, namings and guideEdit
It was discovered by Pierre Méchain in April 1782, then independently by William Herschel in 1793. Herschel's son, John, in his 1864 General Catalogue, described it as a "globular cluster of stars, large, very rich, very much compressed, round, well resolved, clearly consisting of stars".<ref name=Mullaney2007/> It was not until 1947 that Helen Sawyer Hogg added it and three other objects found by Méchain to the modern Catalogue, the latter having contributed several of the suggested observation objects which Messier had verified and added.<ref name=Frommert2007/> The cluster is to be found 2.5° south and slightly west of the star Zeta Ophiuchi.<ref name=Mullaney2007/>
PropertiesEdit
M107 is close to the galactic plane and about 20,900 light-years from Earth<ref name=apj742_1_51/> and Template:Convert from the Galactic Center.<ref name=Zinn1985/> Its orbit is partly as far out as the galactic halo, as is between Template:Convert from the Galactic Center, the lower figure, the "perigalactic distance" sees it enter and leave the galactic bar.<ref name=Pichardo2004/>
It is an Oosterhoff type I<ref name=Olech2001/> cluster with a metallicity of −0.95<ref name=mnras404_3_1203/>Template:Efn and it conforms with the bulk of the halo population.<ref name=Zinn1985/> There are 22 known RR Lyrae variable stars in this cluster and a probable SX Phoenicis variable.<ref name=McCombs2013/>
GalleryEdit
- The globular star cluster Messier 107.jpg
The globular star cluster Messier 107 image taken by the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope
- M107map.png
Map showing the location of M107
See alsoEdit
References and footnotesEdit
Template:Reflist Template:Notelist
External linksEdit
Template:Sky Template:Portal bar Template:Messier objects Template:Ngc65