Of stars


alt label
Of type stars
Of-type stars
dcterms modified equal to or less than 2020-11-05T20:26:32.413Zequal to or more than 2020-11-05T20:26:32.413Z
http://astrothesaurus.org/uat/1137 original
1155 original
http://astrothesaurus.org/uat/428 original
1155 original
definition An O star whose spectrum displays strong N III 4634-4640-4642 emission and strong He II 4686 emission. The N III lines are always much stronger than C III 4647-4650-4651 when the latter are present. Historically, Of stars were considered to belong to the peculiar category, hence the f notation (see below). In his thesis work, Walborn removed them from that category and established them as the normal O-type supergiants. He also used the notation ((f)), (f), and f to describe the progression from strong He II 4686 absorption, through weakened/absent, to emission, respectively, correlated with increasing N III emission strength, subsequently showing that it is a luminosity sequence -- the first such for stars earlier than O9.
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contributor AAS_Frey.Katie_Admin original