Skip to main content
SpringerLink
Log in

The optical spectrum of an LBV candidate in the Cyg OB2 association

  • Published:
Astronomy Reports Aims and scope Submit manuscript

Abstract

We have obtained the first high-spectral-resolution (R=15000 and 60000) optical spectra for the extremely luminous star No. 12, identified with the IR source IRAS 20308+4104 in the Cyg OB2 association. We have identified about 200 spectral features at 4552–7939 Å, including the interstellar NaI, KI lines and numerous DIBs, which are the strongest absorption lines in the spectrum, along with the HeI, CII, and SiII lines. A two-dimensional spectral classification indicates that the star's spectral type is B5±0.5 Ia+. Our analysis of the radial-velocity pattern shows the presence of a radial-velocity gradient in the stellar atmosphere, due to the infall of matter onto the star. The strong Hα emission line displays broad Thompson wings and time-variable core absorption, providing evidence that the stellar wind is inhomogeneous, and a slightly blue-shifted P Cygni absorption profile. We conclude that the wind is time-variable.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. F. Comeron, A. Pasquali, A. Rodighiero, et al., Astron. Astrophys. 389, 874 (2002).

    ADS  Google Scholar 

  2. P. Massey, K. DeGioia-Eastwood, and E. Waterhouse, Astron. J. 121, 1050 (2001).

    Article  ADS  Google Scholar 

  3. D. H. Schulte, Astrophys. J. 128, 41 (1958).

    Article  ADS  Google Scholar 

  4. H. J. Wendker and W. J. Altenhoff, Astron. Astrophys. 92, L5 (1980).

    ADS  Google Scholar 

  5. C. de Jager, Astron. Astrophys. Rev. 8, 145 (1998).

    ADS  Google Scholar 

  6. P. Massey and A. B. Thompson, Astron. J. 101, 1408 (1991).

    Article  ADS  Google Scholar 

  7. S. P. Souza and B. L. Lutz, Astrophys. J. 235, L87 (1980).

    Article  ADS  Google Scholar 

  8. R. M. Humphreys and K. Davidson, Publ. Astron. Soc. Pac. 106, 1025 (1994).

    Article  ADS  Google Scholar 

  9. A. M. van Genderen, Astron. Astrophys. 366, 508 (2001).

    ADS  Google Scholar 

  10. W. W. Morgan, H. L. Johnson, and N. G. Roman, Publ. Astron. Soc. Pac. 66, 85 (1954).

    Article  ADS  Google Scholar 

  11. S. Sharpless, Publ. Astron. Soc. Pac. 69, 239 (1957).

    ADS  Google Scholar 

  12. A. V. Torres-Dodgen, M. Carroll, and M. Tapia, Mon. Not. R. Astron. Soc. 249, 1 (1991).

    ADS  Google Scholar 

  13. T. A. Lozinskaya, V. V. Pravdikova, and A. V. Finogenov, Pis'ma Astron. Zh. 28, 260 (2002) [Astron. Lett. 28, 223 (2002)].

    Google Scholar 

  14. J. H. Bieging, D. C. Abbott, and E. B. Churchwell, Astrophys. J. 340, 518 (1989).

    Article  ADS  Google Scholar 

  15. R. L. White and R. H. Becker, Astrophys. J. 272, L19 (1983).

    Article  ADS  Google Scholar 

  16. C. Leitherer, B. Wolf, O. Stahl, and C. Bertout, Astron. Astrophys. 140, 199 (1984).

    ADS  Google Scholar 

  17. A. Schulz and R. Lenzen, Astron. Astrophys. 121, 158 (1983).

    ADS  Google Scholar 

  18. K. H. Nordsieck, Publ. Astron. Soc. Pac. 86, 324 (1974).

    Article  ADS  Google Scholar 

  19. V. E. Panchuk, I. D. Najdenov, V. G. Klochkova, et al., Bull. Spec. Astrophys. Obs. 44, 127 (1998).

    ADS  Google Scholar 

  20. V. E. Panchuk, N. E. Piskunov, V. G. Klochkova, et al., Preprint No. 169, SAO RAN (Special Astrophys. Obs., 2002).

  21. V. E. Panchuk, M. V. Yushkin, and I. D. Naidenov, Preprint No. 179, SAO RAN (Special Astrophys. Obs., 2003).

  22. G. A. Galazutdinov, Preprint No. 92, SAO (Special Astrophys. Obs., 1992).

  23. V. G. Klochkova, E. L. Chentsov, N. S. Tavolzhskaya, and G. A. Proskurova, Preprint No. 183 (Special Astrophys. Obs., 2003).

  24. J. M. Marlborough, Astrophys. J. 156, 135 (1969).

    Article  ADS  Google Scholar 

  25. J. I. Castor, L. F. Smith, and D. van Blerkom, Astrophys. J. 159, 1119 (1970).

    Article  ADS  Google Scholar 

  26. A. P. Bernat and D. L. Lambert, Publ. Astron. Soc. Pac. 90, 520 (1978).

    ADS  Google Scholar 

  27. A. Lèbre and D. Gillet, Astron. Astrophys. 255, 221 (1992).

    ADS  Google Scholar 

  28. B. Wolf, O. Stahl, M. J. H. de Groot, and C. Sterken, Astron. Astrophys. 99, 351 (1981).

    ADS  Google Scholar 

  29. F. Scappini, S. Casu, C. Cecchi-Pestellini, and M. Olberg, Mon. Not. R. Astron. Soc. 337, 495 (2002).

    Article  ADS  Google Scholar 

  30. S. P. Souza and B. L. Lutz, Astrophys. J. 216, L49 (1977).

    Article  ADS  Google Scholar 

  31. R. Gredel and G. Munch, Astron. Astrophys. 285, 640 (1994).

    ADS  Google Scholar 

  32. F. H. Chaffee, Jr. and R. E. White, Astrophys. J., Suppl. Ser. 50, 169 (1982).

    Article  ADS  Google Scholar 

  33. R. Gredel, J. H. Black, and M. Yan, Astron. Astrophys. 375, 553 (2001).

    ADS  Google Scholar 

  34. B. Bohannan and P. S. Conti, Astrophys. J. 204, 797 (1976).

    Article  ADS  Google Scholar 

  35. J. Brand and L. Blitz, Astron. Astrophys. 275, 67 (1993).

    ADS  Google Scholar 

  36. R. M. Humphreys, Astrophys. J. Suppl. 38, 309 (1978).

    Article  ADS  Google Scholar 

  37. D. Hoffleit and C. Jaschek, The Bright Stars Catalogue (Yale Univ. Observ., 1982).

  38. D. Hoffleit, M. Saladyga, and P. Wlasuk, Supplement to the Bright Stars Catalogue (Yale Univ. Observ., 1983).

  39. R. J. Reynolds, Astrophys. J. 268, 698 (1983).

    Article  ADS  Google Scholar 

  40. T. M. Dame, D. Hartmann, and P. Thaddeus, Astrophys. J. 547, 792 (2001).

    Article  ADS  Google Scholar 

  41. T. G. Sitnik, A. M. Mel'nik, and V. V. Pravdikova, Astron. Zh. 78, 40 (2001) [Astron. Rep. 45, 34 (2001)].

    Google Scholar 

  42. B. J. McCall, K. H. Hinkle, T. R. Geballe, et al., Astrophys. J. 567, 391 (2002).

    Article  ADS  Google Scholar 

  43. L. M. Hobbs, Astrophys. J. 157, 135 (1969).

    ADS  Google Scholar 

  44. B. J. McCall, D. G. York, and T. Oka, Astrophys. J. 531, 329 (2000).

    Article  ADS  Google Scholar 

  45. B. Wolf and O. Stahl, Astron. Astrophys. 235, 340 (1990).

    ADS  Google Scholar 

  46. O. Stahl, T. Gaeng, C. Sterken, et al., Astron. Astrophys. 400, 279 (2003).

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz, Karachai-Cherkessian Republic, 369167, Russia

    V. G. Klochkova & E. L. Chentsov

Authors
  1. V. G. Klochkova
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. E. L. Chentsov
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

__________

Translated from Astronomicheski\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l} \) Zhurnal, Vol. 81, No. 12, 2004, pp. 1104–1118.

Original Russian Text Copyright © 2004 by Klochkova, Chentsov.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Klochkova, V.G., Chentsov, E.L. The optical spectrum of an LBV candidate in the Cyg OB2 association. Astron. Rep. 48, 1005–1018 (2004). https://doi.org/10.1134/1.1836024

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1134/1.1836024

Keywords

Search

Navigation