Hostname: page-component-7bb8b95d7b-nptnm Total loading time: 0 Render date: 2024-09-13T03:42:05.587Z Has data issue: false hasContentIssue false
  • English
  • Français

Binaries with Invisible Massive Components

Published online by Cambridge University Press:  12 April 2016

Drahomír Chochol  and
Pavel Mayer
Drahomír Chochol
Affiliation:
Astronomical Institute of the Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovak Republic
Pavel Mayer
Affiliation:
Astronomical Institute of the Charles University, V Holešovičkách 2, 180 00 Praha 8, Czech Republic

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.

V505 Mon is an early type eclipsing binary (usually classified as B5 Ib), in which only spectral lines of the primary component are visible. The radial velocity curve provides f(m) = 4.6 M⊙, suggesting that the secondary, invisible component is more massive. We have found evidence that this star is hidden from view by the disk detected during the primary eclipse. The structure of the disk can be characterized by a central ionization zone surrounded by the neutral outer parts. The profiles of the CII 1335/6 doublet lines were used to derive the rotational velocity of the disk as well as the velocity of the stream from the primary component to the disk. The masses of the components, deduced from the fractional size of the disk, are M1 = 1 M⊙ and M2 = 6.1 M⊙. Due to the low mass of the primary component its supergiant nature can be ruled out. Additional matter of a cloudy nature is present in the system and both components are embedded in an extended atmosphere. V505 Mon seems to be a prototype of the whole group of similar early-type binaries, in which the more massive component is hidden by a circumstellar medium, most likely a disk. Probable members are V742 Cas, V1362 Cyg, V2174 Cyg, V447 Sct and FY Vel with orbital periods between 33 and 225 days. Emission in Ha is always present, but there are no emissions in IUE spectra, so these binaries are distinct from the W Ser type. The evolutionary state of the members of this group is not yet understood.

Type
Research Article
Information
International Astronomical Union Colloquium , Volume 187: Exotic Stars as Challenges to Evolution , 2002 , pp. 143 - 148
Copyright
Copyright © Astronomical Society of the Pacific 2002

References

Bolton, C.T., & Hurkens, R. 2001, Publ. Astron. Inst. AS CR, 89, 23 Google Scholar
Chochol, D., & Kučera, A. 1981, IBVS, 1998Google Scholar
Garrison, R.F., Hiltner, W.A., & Schild, R.E. 1977, ApJS, 35, 111 Google Scholar
Hill, G., Hilditch, R.W., & Pfannenschmidt, E. 1976, Publ. DAO Victoria, 15, 1 Google Scholar
Hiltner, W.A. 1956, ApJS, 2, 313 Google Scholar
Hoag, A.A., & van Smith, E.P. 1959, PASP, 71, 32 Google Scholar
Hubeny, I., Lanz, T., & Jeffery, C.S. 1995, Tlusty & Synspec - A User’s Guide (Greenbelt: NASA)Google Scholar
Hutchings, J.B., & Redman, R.O. 1973, MNRAS, 163, 219 Google Scholar
Mayer, P., Chochol, D., Drechsel, H., Lorenz, R., Plavec, M., Raja, T., & Batten, A.H. 2001, A&A, 375, 434 Google Scholar
Peters, G.J. 1989, Space Sci. Rev., 50, 9 CrossRefGoogle Scholar
Sahade, J., Barbá, R., & Kondo, J. 1992, ApJS, 81, 303 Google Scholar
Stagni, R., Margoni, R., & Mammano, A. 1982, Ap&SS, 88, 115 Google Scholar
Thackeray, A.D. 1971, MNRAS, 154, 103 CrossRefGoogle Scholar
Vogt, N., & Sterken, C. 1993, IBVS, 3958 Google Scholar
Wachmann, A.A. 1966, Astr. Abh. Hamburg-Bergedorf, 7, 341 Google Scholar
Walborn, N.R. 1971, ApJ, 164, L67 CrossRefGoogle Scholar