Addressing the Question Posed by the Of?p Stars: HD191612

Lennon, D. J.; Howarth, I. D.; Herrero, A.; Walborn, N. R.
Referencia bibliográfica

The Newsletter of the Isaac Newton Group of Telescopes (ING Newsl.), issue no. 9, p. 18-19.

Fecha de publicación:
3
2005
Número de autores
4
Número de autores del IAC
1
Número de citas
0
Número de citas referidas
0
Descripción
There are three known Of?p stars in our galaxy, they are the well known peculiar stars HD108, HD148937 and HD191612. The question mark in their spectral classification was introduced by Walborn (1972) to indicate doubt that these stars are normal Of supergiants. They are characterised by their CIII 4647, 4650, 4651 emission lines being comparable in strength to their NIII 4634, 4640, 4642 emission lines, unlike normal Of supergiants where the CIII lines are always much weaker. In addition the ultra-violet spectra of Of?p stars also exhibit a stellar wind morphology more akin to O-type giants than to Of supergiants. HD191612 came to our attention when N. R. Walborn noticed that the spectrum discussed by Herrero et al. (1992) was different from the discovery spectrum of Walborn (1973).