What is Stellar birthline?
The '''stellar birthline''' is a line in the [[Hertzsprung–Russell diagram]] that relates the effective temperature and luminosity of [[Pre-main-sequence star|pre-main-sequence stars]] on the start of their contraction.<ref>{{Cite journal|last=Stahler|first=S. W.|date=1983-11-01|title=The birthline for low-mass stars.|url=https://ui.adsabs.harvard.edu/abs/1983ApJ...274..822S|journal=The Astrophysical Journal|volume=274|pages=822–829|doi=10.1086/161495|bibcode=1983ApJ...274..822S |issn=0004-637X}}</ref> To this point, the objects are [[Protostar|protostars]], and are so deeply in the cloud of dust and gas from which they are forming that they radiate only in far [[infrared]] and [[Millimetre|millimeter]] wavelengths. [[File:HR_Diagram_Stellar_birthline.png|thumb|Image showing the '''stellar birthline''' in the [[Hertzsprung–Russell diagram]].]] When [[Stellar wind|stellar winds]] disperse this cloud, the [[star]] becomes visible as pre-main-sequence object. The set of locations on the Hertzsprung–Russell diagram where these newly visible stars form is called the birthline and is found above the [[main sequence]]. == Location == Location of the stellar birthline depends on detail in the [[Accretion (astrophysics)|accretion]] rate onto the star and [[geometry]] of this accretion, i.e. whether or not it is happening through an [[accretion disk]]. This means that the birthline is not an infinitely thin curve, but has a finite thickness on the Hertzsprung-Russell diagram. == References == <references /> [[Category:Astronomy]]