... The blue dots represent massivestars with short main sequence lifetimes. ... the main sequence lifeftime of a 2 solar massstar is about one billion years, then ... Thus, identifying the most massivestar which is still on the main sequence is an ...
... In addition, to the ionization these massivestars will ultimately terminate their lives as Supernova . ... These massivestars and supernovae are able to heat the gas an induce a wind. ...
... Star formation is often best manifested by bright H II regions.These are regions of hydrogen which have been ionized by ultraviolet photons which are emitted from massivestars (typically stars more than 20 times the mass of the Sun). ...
... or loose associations of hot and massive OB stars, that are apparently being created ... reaches about one tenth of the total mass, the star embarks on a rebuilding of its ...
... galaxy, the present day star formation rate is quite low and such star formation appears to be deficient in massivestars ... image selected fields associated with spiral arm regions in M31 to improve the census of hot massivestars in these regions ...
... It is a nice illustration of the combined effections of ionization and scattering caused by the large yield of blue and UV photons from newly formed massivestars. ...