Editing Blue straggler (section)

==Description==
Standard theories of [[stellar evolution]] hold that the position of a star on the [[Hertzsprung–Russell diagram]] should be determined almost entirely by the initial [[mass]] of the star and its age. In a cluster, stars all formed at approximately the same time, and thus in an H–R diagram for a cluster, all stars should lie along a clearly defined curve set by the age of the cluster, with the positions of individual stars on that curve determined solely by their initial [[mass]]. With masses two to three times that of the rest of the main-sequence cluster stars, blue stragglers seem to be exceptions to this rule.<ref name="apod">{{Cite APOD | title = Blue Stragglers in NGC 6397 | date = 2000-06-22 | access-date = 2010-01-18}}</ref> The resolution of this problem is likely related to [[Stellar collision|interactions]] between two or more stars in the dense confines of the clusters in which blue stragglers are found. Blue stragglers are also found among field stars, although their detection is more difficult to disentangle from genuine massive main sequence stars. Field blue stragglers can however be identified in the Galactic halo, since all surviving main sequence stars are low mass.<ref name=":0">{{Cite journal|last=Casagrande|first=Luca|date=2020-06-10|title=Connecting the Local Stellar Halo and Its Dark Matter Density to Dwarf Galaxies via Blue Stragglers|journal=The Astrophysical Journal|volume=896|issue=1|pages=26|doi=10.3847/1538-4357/ab929f|issn=1538-4357|arxiv=2005.09131|bibcode=2020ApJ...896...26C|hdl=1885/268844 |s2cid=218684551 |doi-access=free }}</ref>