Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-27T05:04:40.987Z Has data issue: false hasContentIssue false
  • English
  • Français

The WO stars and their environment

Published online by Cambridge University Press:  07 August 2017

V.F. Polcaro ,
R. Viotti ,
C. Rossi  and
L. Norci
V.F. Polcaro
Affiliation:
1 Istituto di Astrofisica Spaziale, CNR, Via Enrico Fermi 21, 00044 Frascati, Italy
R. Viotti
Affiliation:
1 Istituto di Astrofisica Spaziale, CNR, Via Enrico Fermi 21, 00044 Frascati, Italy
C. Rossi
Affiliation:
2 Istituto Astronomico, Università La Sapienza, Via Lancisi 29, 00161 Roma, Italy
L. Norci
Affiliation:
3 Max-Plank Institut für Extraterrestrische Physik, Postfach 1603, D-85740 Garching bei München, B.R. Deutschland

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The WO stars form a subgroup of the WR class characterized by a strong O VI emission at 382 nm (Sanduleak 1971; Barlow & Hummer 1982). In 1989–90 we observed intermediate resolution spectra of the four Sanduleak WO stars and of their surrounding nebulosities using the Bologna-Loiano 1.52m and ESO-La Silla 1.52m and 2.2m telescopes (e.g., Polcaro et al. 1991, 1992, 1994 in preparation). Fig. 1 shows that the spectra are similar but with some striking differences among the four stars. They can be arranged in a sequence in order of increasing ionization: Sand 2, Sand 1, Sand 5, Sand 4 (see Table 1). Sand 4 is a binary system, and the continuum of the O4 companion dominates over that of the WO star. In the other objects, the reddening-corrected continuum can be fitted by a 80 000 K BB, in agreement with the high ionization level of their emission spectra.

Type
Session I - Basic parameters, properties of single Wolf-Ray et stars
Information
Symposium - International Astronomical Union , Volume 163: Wolf-Rayet Stars: Binaries, Colliding Winds, Evolution , 1995 , pp. 68 - 69
Copyright
Copyright © Kluwer 1995 

References

Barlow, M.J., Hummer, D.C. 1982, in: de Loore, C.W.H. & Willis, A.J. (eds.), Wolf-Rayet Stars: Observations, Physics, Evolution, Proc. IAU Symp. No. 99 (Dordrecht: Reidel), p. 387 Google Scholar
Dopita, M.A., Lozinskaya, T., McGregor, P.J., Rawling, S.J. 1990, ApJ 351, 563 Google Scholar
Melnick, J., Hyedari-Malayeri, M. 1991, in: van der Hucht, K.A. & Hidayat, B. (eds.), Wolf-Rayet Stars and Interrelations with Other Massive Stars in Galaxies, Proc. IAU Symp. No. 143 (Dordrecht: Kluwer), p. 409 Google Scholar
Polcaro, V.F., Rossi, C., Norci, L., Giovannelli, F., Manchanda, R.K. 1991, A&A 252, 590 Google Scholar
Polcaro, V.F., Viotti, R., Rossi, C., Norci, L. 1992, A&A 265, 563 Google Scholar
Sanduleak, N. 1971, ApJ (Letters) 164, L71 Google Scholar