pg 1159 stars造句

• Some PG 1159 stars have varying luminosities.
• RX J0122.9-7521 has been identified as a galactic PG 1159 star.
• PG 1159 stars reach luminosities of ~ 10 38 erg / s but form a rather distinct class.
• "' PG 1159-035 "'is the prototypical PG 1159 star after which the class of PG 1159 stars was named.
• "' PG 1159-035 "'is the prototypical PG 1159 star after which the class of PG 1159 stars was named.
• PG 1159 stars are a group of very hot, often pulsating WDs for which the prototype is PG 1159 dominated by carbon and oxygen in their atmospheres.
• It is thought that the atmospheric composition of PG 1159 stars is odd because, after they have left the asymptotic giant branch, they have reignited helium fusion.
• As a result, a PG 1159 star's atmosphere is a mixture of material which was between the hydrogen-and helium-burning shells of its AGB star progenitor ., ?.
• The pulsators are known as GW Virginis stars ( DO variables, sometimes also known as PG 1159 stars ), V777 Herculis stars ( DB variables ) and ZZ Ceti stars ( DA variables ).
• A "'pulsating white dwarf "'is a white dwarf star whose luminosity PG 1159 . ( Some authors also include non-PG 1159 stars in the class of GW Vir stars . ) GW Vir stars may be subdivided into "'DOV "'and "'PNNV "'stars; they are not, strictly speaking, white dwarfs but " pre-white dwarfs " which have not yet reached the white dwarf region on the Hertzsprung-Russell diagram . and in May 2012, the first extremely low mass variable ( "'ELMV "') white dwarf was reported.