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Astron. Astrophys. 332, 909-927 (1998)

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SZ Camelopardalis - an early-type eclipsing binary embedded in a multiple system * **

Reinald Lorenz 1, Pavel Mayer 2 and Horst Drechsel 1

1 Dr. Remeis-Sternwarte Bamberg, Astronomisches Institut der Universität Erlangen-Nürnberg, Sternwartstraße 7, D-96049 Bamberg, Germany
2 Astronomical Institute, Charles University, védská 8, CZ-150 00 Praha 5, Czech Republic

Received 14 October 1997 / Accepted 20 November 1997


We present a spectroscopic and photometric analysis of a complex multiple system: the early-type eclipsing binary SZ Cam (O9 IV + B0.5 V) is physically bound to a third body, which itself is a close binary; this quadruple system has a visual companion, which shows evidence for duplicity as well. A careful deconvolution of spectral lines in our CCD spectra yields rv curves of the SB2 system ([FORMULA] ; [FORMULA]) and of its SB1 companion ([FORMULA]). UBV light curves of Kitamura & Yamasaki (1970) are reanalyzed and absolute dimensions of the eclipsing pair are derived. Both components of this close detached binary are overluminous for their masses. The photometric solution suggests third light of [FORMULA], which confirms the spectroscopic and speckle interferometric detection (Mason 1995) of the third component. The observed light time effect encompasses the long period range to [FORMULA] 50-60 years. Comparison of calculated orbits with the speckle interferometric result yields a distance of 1050 pc, which is [FORMULA] larger than the value derived from the absolute bolometric magnitude, and [FORMULA] above the photometric distance of the open cluster NGC 1502. The minimum mass of the third component is 20-30 [FORMULA], depending on the long orbital period and inclination assumed. This high mass supports the binary nature of the third body. An analysis of the spectra of the visual companion ADS 2984 A confirms its binarity.

Key words: stars: individual: SZ Camelopardalis – binaries: eclipsing – binaries: spectroscopic – stars: early-type – stars: fundamental parameters

* Based on observations collected at the German-Spanish Astronomical Centre, Calar Alto, operated by the Max-Planck-Institut für Astronomie, Heidelberg, jointly with the Spanish National Commission for Astronomy
** This paper is dedicated to the memory of Professor Dr. Jürgen Rahe, who died in a tragic accident on June 18, 1997. During more than a decade at Remeis Observatory Bamberg, Dr. Rahe has greatly promoted and contributed to close binary research.

Send offprint requests to: R. Lorenz

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© European Southern Observatory (ESO) 1998

Online publication: March 30, 1998