Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-12T18:53:22.342Z Has data issue: false hasContentIssue false
  • English
  • Français

Abundances in Wolf-Rayet Stars, LBVs and OBN Stars

Published online by Cambridge University Press:  19 July 2016

Allan J Willis
Allan J Willis*
Affiliation:
Department of Physics & Astronomy University College London Gower Street London WC1E 6BT, UK

Abstract

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.

Current knowledge of the chemical nature of WR stars determined from UV, optical and IR spectral analyses, is reviewed. By number, the H/He ratio is low in most WN stars: 10 ≥ H/He ≥ 0.4 for WNL stars; 3.0 ≥ H/He ≥ 0.0 for WNE stars with most having near zero H-abundances. The C/N ratio in WN stars lies in the range 1–6 × 10−2, whilst N/He ∼10−4 − 4 × 10−3. These abundances for WN stars are broadly consistent with equilibrium CNO-burning products. In WC stars H/He=0 whilst C/He ∼ 0.1 − 0.7 with some evidence for increasing values from WC7 → WC4. N is highly deficient in WC stars, with C/N≥ 60, and for HD 165763 O/C ≤ 0.2 is deduced. In γ Velorum (WC8+O9), IR spectra give a value of Ne/He = 1.0×10-3 (about twice solar). Thus WC abundances are broadly consistent with He-burning products, although the Ne abundance appears lower than predicted. WO stars show C/He ∼ 0.2 − 0.7, and O/He ∼ 0.03 − 0.1, revealing both He-burning and α-capture products. Ring nebulae around several WN stars shown enhanced He and N, consistent with mass loss enrichment expectations from their chemically evolved central stars. Enhanced He (and probably N) is also seen in the atmospheres of several LBVs, OBN and Of stars - potential precursors of, at least, some WN subtypes.

Type
The Giants
Information
Symposium - International Astronomical Union , Volume 145: Evolution of Stars: The Photospheric Abundance Connection , 1991 , pp. 195 - 207
Copyright
Copyright © Kluwer 1991 

References

Abbott, D.C., Bieging, J.H., Churchwell, E., & Torres, A.V., 1986, Astrophys. J., 303, 239 Google Scholar
Abbott, D.C., & Conti, P.S., 1987, Ann. Rev. Ast. Astrophys. , 25, 113 Google Scholar
Allen, D.R., Jones, T.J., & Hyland, A.R., 1985, Astrophys. J., 291, 280 Google Scholar
Bappu, M.K.V., 1973, Proc. IAU Symp. No. 49 , (eds Bappu, M K V & Sahade, J), D. Reidel, p 59 Google Scholar
Barlow, M.J., & Hummer, D.G., 1982, Proc IAU Symp. No. 99 , (eds de Loore, C & Willis, A J), D. Reidel, p 387 Google Scholar
Barlow, M.J., Roche, P.F., & Aitken, D.K., 1988, Mon. Not. R. astr. Soc. , 232, 821 Google Scholar
Bhattia, A.K., & Underhill, A.B., 1986, Astrophys. J. Suppl. , 60, 323 Google Scholar
Bohannan, B., 1990, in Properties of Hot Luminous Stars , (ed. Garmany, C D), P.A.S.P. Conf. Ser., 7, p 39 Google Scholar
Bohannan, B., Abbott, D.C., Voels, S.A., & Hummer, D.G., 1986, Astrophys. J. , 308, 728 CrossRefGoogle Scholar
Castor, J.I., 1970, Mon. Not. R. astr. Soc. , 149, 111 Google Scholar
Castor, J.I., & van Blerkom, D., 1970, Astrophys. J. , 161, 485 CrossRefGoogle Scholar
Chu, Y.-H., Gull, T.R., Treffers, R.R., Kwitter, K.B., & Troland, T.H., 1983, Astrophys. J. , 254, 562 Google Scholar
Conti, P.S., Leep, E.M., & Perry, D., 1983, Astrophys. J. , 268, 228 Google Scholar
Conti, P.S., & Massey, P., 1989, Astrophys. J. , 337, 251 CrossRefGoogle Scholar
Conti, P.S., Massey, P, & Garmany, C.D., 1990, Astrophys. J. , 341, 113 CrossRefGoogle Scholar
Conti, P.S., Massey, P., & Vreux, J-M., 1990, Astrophys. J. , 354, 359 CrossRefGoogle Scholar
Crowther, P., Smith, L.J., & Willis, A.J., 1990, in Proc. IAU Symp. No. 143 , (eds. van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
Davidson, K., Walborn, N.R., & Gull, T.R., 1982, Astrophys. J. , 254, L47 Google Scholar
Davidson, K., Dufour, R.J., Walborn, N.R., & Gull, T.R., 1986, Astrophys. J. , 305, 867 Google Scholar
Davidson, K., Moffat, A.F.J., & Lamers, H., (eds), 1989, Proc IAU Coll. No. 113, (Physics of Luminous Blue Variables) , Kluwer Acad. Pub. Google Scholar
Deacon, J.R., & Barlow, M.J., 1990, in Proc. IAU Symp. No. 143 , (eds van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
de Loore, C., & Willis, A.J., (eds.), 1982, Proc IAU Symp. No 99 (WR stars - observations, physics & evolution) , D. Reidel Pub. Co. Google Scholar
de Loore, C., Willis, A.J., & Laskarides, P., (eds.), 1986, Proc. IAU Symp. No. 116 (Luminous stars & associations in galaxies) , D. Reidel Pub. Co. Google Scholar
Hamann, W-R., 1990, in Proc. IAU Symp. No. 143 , (eds. van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
Hamann, W-R., & Schmutz, W., 1987, Astr. Astrophys. , 174, 173 Google Scholar
Hamann, W-R., Schmutz, W., & Wessolowski, U., 1988, Astr. Astrophys. , 194, 190 Google Scholar
Hamann, W-R., & Wessolowski, U., 1990, Astrophys. J. , 227, 171 Google Scholar
Hamann, W-R., Wessolowski, U., Schwarz, E., Dunnebeil, G., & Schmutz, W., 1990, in Properties of Hot Luminous stars , (ed. Garmany, C D), P.A.S.P. Conf. Ser., 7, p 259 Google Scholar
Hillier, D.J., 1987a, Astrophys. J. Suppl. , 63, 947 Google Scholar
Hillier, D.J., 1987b, Astrophys. J. Suppl. , 63, 965 Google Scholar
Hillier, D.J., 1988, Astrophys. J. , 327, 822 Google Scholar
Hillier, D.J., 1989, Astrophys. J. , 347, 392 Google Scholar
Hillier, D.J., 1990a, in Properties of Hot Luminous stars , (ed Garmany, C D), P.A.S.P. Conf. Ser., 7, p 340 Google Scholar
Hillier, D.J., 1990b, Proc IAU Symp. No. 143 , (eds van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
Humphreys, R.M., & Davidson, K., 1979, Astrophys. J. , 232, 409 Google Scholar
Kingsburgh, R., & Barlow, M.J., 1990, in Proc IAU Symp. No. 143 , (eds van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
Kudritzki, R.P., Groth, H.G., Butler, K., Husfeld, D., Becker, S., Eber, F., & Fitzpatrick, E., 1987, ESO SN 1981A Workshop ,Google Scholar
Langer, N., 1990, in Properties of Hot Luminous stars , (ed. Garmany, C D), P.A.S.P. Conf. Ser., 7, p 328 Google Scholar
Leitherer, C., & Zickgraf, F.-J., 1987, Astr. Astrophys. , 175, 208 Google Scholar
Maeder, A., 1983, Astr. Astrophys. , 120, 113 Google Scholar
Maeder, A., 1990, Astr. Astrophys. Suppl. , 84, 139 Google Scholar
Maeder, A., & Meynet, G., 1987, Astr. Astrophys. , 182, 243 Google Scholar
Nugis, T., 1975, Proc IAU Symp. No. 67 , (eds Sherwood, V E & Lukas, P), D. Reidel, p 291 Google Scholar
Nugis, T., 1982a, Proc IAU Symp. No. 99 , (eds. de Loore, C & Willis, A J), D. Reidel., p 127 Google Scholar
Nugis, T., 1982b, Proc IAU Symp. No. 99 , (eds de Loore, C & Willis, A J), D. Reidel, p131 Google Scholar
Nussbaumer, H., Schmutz, W., Smith, L.J., & Willis, A.J., 1982, Astr. Astrophys. Suppl. , 47, 257 Google Scholar
Oegerle, W.R., & van Blerkom, D., 1976, Astrophys. J. , 206, 150 Google Scholar
Prantzos, N., Doom, C., Arnould, M., & de Loore, C., 1986, Astrophys. J. , 304, 695 Google Scholar
Rosa, M.R., & Mathis, J.S., 1990, in Properties of Hot Luminous Stars , (ed Garmany, C D), P.A.S.P. Conf. Ser., 7, p 135 Google Scholar
Sanduleak, N., 1971, Astrophys. J. , 164, L71 Google Scholar
Schmutz, W., Hamann, W-R., & Wessolowski, U., 1989, Astr. Astrophys. , 210, 236 Google Scholar
Schmutz, W., Leitherer, C., Hubeny, I., Vogel, M., Hamann, W-R., & Wessolowski, U., 1990, Astr. Astrophys. , submitted Google Scholar
Schonberner, D., Herrero, A., Becker, S., Eber, F., Butler, K., Kudritzki, R.P., & Simon, K.P., 1988, Astr. Astrophys. , 197, 209 Google Scholar
Shore, S.N., & Sanduleak, N., 1983, Astrophys. J. , 273, 177 Google Scholar
Shore, S.N., Sanduleak, N., & Allen, D.A., 1987, Astr. Astrophys. , 176, 59 Google Scholar
Smith, L.F., 1973, Proc IAU Symp. No. 49 , (eds Bappu, M K V & Sahade, J), D. Reidel, p 15 Google Scholar
Smith, L.F., & Kuhi, L.V., 1981, An atlas of WR line profiles , JILA Report No. 117 Google Scholar
Smith, L.F., & Hummer, D.G., 1988, Mon. Not. R. astr. Soc. , 230, 511 CrossRefGoogle Scholar
Smith, L.J., & Willis, A.J., 1982, Mon. Not. R. astr. Soc. , 201, 451 Google Scholar
Smith, L.J., & Willis, A.J., 1983, Astr. Astrophys. Suppl. , 54, 229 Google Scholar
Sobolev, V.V., 1960, The moving envelopes of stars , Harvard Univ. Press Google Scholar
Torres, A.V., 1988, Astrophys. J. , 325, 759 Google Scholar
Torres, A.V., Conti, P.S., & Massey, P., 1986, Astrophys. J. , 300, 379 Google Scholar
van der Hucht, K.A., Conti, P.S., Lundstrom, I., & Stenholm, B., 1981, Spac. Sci. Rev. , 28, 227 Google Scholar
van der Hucht, K.A., & Olnon, , 1985, Astr. Astrophys. , 149, L17 Google Scholar
van der Hucht, K.A., & Hidayat, B., (eds.), 1990, Proc IAU Symp. No. 143 (WR stars and interrelations with other massive stars in galaxies) , Kluwer Acad. Pub. Google Scholar
Vilchez, J.M., & Esteban, C., 1990, Proc. IAU Symp. No. 143 , (eds van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub. in press Google Scholar
Voels, S.A., Bohannan, B., Abbott, D.C., & Hummer, D.G., 1989, Astrophys. J. , 340, 1073 Google Scholar
Vreux, J-M., Dennefeld, M., Andrillat, Y., & Rochowich, K., 1989, Astr. Astrophys. Suppl. , 226, 421 Google Scholar
Walborn, N.R., 1976, Astrophys. J. , 205, 419 Google Scholar
Walborn, N.R., 1982, Astrophys. J. , 256, 452 Google Scholar
Walborn, N.R., 1988, Proc. IAU Coll. No. 108 , (ed. Nomoto, K), Springer-Verlag Pub., p 70 Google Scholar
Wessolowski, U., Schmutz, W., & Hamann, W-R., 1988, Astr. Astrophys. , 194, 160 Google Scholar
Willis, A.J., 1980, Proc. 2nd European IUE Conf. , ESA Sp-157, p il Google Scholar
Willis, A.J., 1982a, Proc IAU Symp. No. 99 , (eds de Loore, C & Willis, A J), D. Reidel, p 87 Google Scholar
Willis, A.J., 1982b, Mon. Not. R. astr. Soc. , 198, 897 Google Scholar
Willis, A.J., 1990, in Proc. IAU Symp. No. 143 , (eds. van der Hucht, K A & Hidayat, B), Kluwer Acad. Pub., in press Google Scholar
Willis, A.J., & Wilson, R., 1978, Mon. Not. R. astr. Soc. , 182, 559 Google Scholar
Willis, A.J., van der Hucht, K.A., Conti, P.S., & Garmany, C.D., 1986, Astr. Astrophys. Suppl. , 63, 417 Google Scholar
Willis, A.J., & Stickland, D.J., 1990, Astr. Astrophys. , 232, 89 Google Scholar