Hydrogen-deficient star

Born-again star region in an H-R diagram.
About 25% of post-AGB hydrogen-deficient stars experience a born-again phase, where they migrate over time between post-AGB and AGB regions in a Hertzsprung-Russell diagram.[1]

A hydrogen-deficient star is a type of star that has little or no hydrogen in its atmosphere.[2] Hydrogen deficiency is unusual in a star, as hydrogen is typically the most common element in a stellar atmosphere. Despite being rare, there are a variety of star types that display a hydrogen deficiency.

  1. ^ Kurtz, C. Aerts, J. Christensen-Dalsgaard, D.W. (2010). Asteroseismology (Online-Ausg. ed.). Dordrecht: Springer. p. 37. ISBN 978-1-4020-5803-5.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. ^ Jeffery, C. Simon (2008). Klaus Werner and Thomas Rauch (ed.). Hydrogen-Deficient Stars: An Introduction. Hydrogen-Deficient Stars ASP Conference Series. Vol. 391. San Francisco: Astronomical Society of the Pacific. pp. 3–16. Bibcode:2008ASPC..391....3J.