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70 Years of observations of 4 Her: changes through three shell episodes

Published online by Cambridge University Press:  26 May 2016

P. Koubský
Affiliation:
Astronomical Institute, Academy of Sciences of the Czech Republic, 251 65 Ondřejov, Czech Republic
P. Harmanec
Affiliation:
Astronomical Institute, Academy of Sciences of the Czech Republic, 251 65 Ondřejov, Czech Republic
J. Horn
Affiliation:
Astronomical Institute, Academy of Sciences of the Czech Republic, 251 65 Ondřejov, Czech Republic
A.-M Hubert
Affiliation:
Observatoire de Paris, Section d'Astrophysique de Meudon, URA 335 du CNRS, F-92195 Meudon Cedex, France
H. Hubert
Affiliation:
Observatoire de Paris, Section d'Astrophysique de Meudon, URA 335 du CNRS, F-92195 Meudon Cedex, France
M. Floquet
Affiliation:
Observatoire de Paris, Section d'Astrophysique de Meudon, URA 335 du CNRS, F-92195 Meudon Cedex, France

Extract

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4 Her (HD 142926, HR 5938; V=5m.75, v.sini=300 km s-1) is a well known and rather frequently observed Be and shell star. It was recognized as a Be star by Heard (1939) and Mohler (1940). The estimates of its spectral type by different authors vary between B7 IV-V and B9e. Hubert (1971) reported remarkable spectral changes of 4 Her which occurred between 1953 and 1970. Harmanec et al. (1973) discovered periodic radial-velocity variations of the hydrogen shell lines with a period 46.023 days and suggested the object is a single-line spectroscopic binary. The system elements were later refined by Heard et al. (1975) to P=46.194 days, K=12 km s-1 and e=0.3. In a subsequent paper, Harmanec et al. (1976) studied the variations of emission and absorption components of the hydrogen lines and concluded that 4 Her is an interacting binary and that the observed eccentricity of the orbit is spurious, caused by the effects of circumstellar matter.

Type
6. Be Stars: Circumstellar Environment
Copyright
Copyright © Kluwer 1994 

References

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