Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-26T15:15:37.760Z Has data issue: false hasContentIssue false
  • English
  • Français

ER Del: A True Symbiotic S Star?

Published online by Cambridge University Press:  12 April 2016

Hollis R. Johnson  and
Thomas B. Ake
Hollis R. Johnson
Affiliation:
Indiana University
Thomas B. Ake
Affiliation:
Space Telescope Sci. Inst./CSC

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.

ER Del = BD+8:4506 is a faint (m ≈ 10) irregularly variable PRG star classified spectral type S5.5/2.5 (Ake 1979). Spectra show H alpha in emission and a strong UV continuum with emission lines of C IV, Si III], and C III] — characteristic of symbiotic-like stars. Although a few other MS and S stars have hot companions, this is the first to show hydrogen emission lines in the optical region. It has been suggested (Smith & Lambert 1986; Little et al. 1987) that all Tc-deficient PRG stars are accidental; that is, they arose by mass transfer when the currently degenerate companion was itself an AGB star. Indeed, the Tc-deficient S stars HR 1105 (Ake, Johnson and Peery 1988) and HD 35155 (Ake and Johnson 1988) and the R8 star HD 59643 (Johnson et al. 1988) not only have hot, subluminous companions, but also are interacting systems - a sign the components are close enough for mass transfer to have occurred. An accretion disk is probably present.

Type
5. Chromospheres, Winds and Mass Loss
Information
International Astronomical Union Colloquium , Volume 106: Evolution of Peculiar Red Giant Stars , 1989 , pp. 371
Copyright
Copyright © Cambridge University Press 1989

References

Ake, T.B. 1979, Astrophys. j., 234, 538.CrossRefGoogle Scholar
Ake, T.B., Johnson, H.R. 1988, Astrophys. J.. submitted.Google Scholar
Ake, T.B., Johnson, H.R., Peery, B.F. 1988, A Decade of UV Astronomy with the IUE Satellite, ed. Rolfe, E.J.. ESA SP-281. in press.Google Scholar
Johnson, H.R., Eaton, J.A., Querci, F.R., Querci, M., Baumert, J.H. 1988, Astron. Astrophys.. in press.Google Scholar
Little, S.J., Little-Marenin, I., Bauer, W. 1987, Astron. J. 94. 981.CrossRefGoogle Scholar
Smith, V.V. and Lambert, D.L. 1986, Astrophys. J., 311, 843.CrossRefGoogle Scholar