Freyhammer, L. M. ; Hensberge, H. ; Sterken, C. ; Pavlovski, K. ; Smette, A. ; Ilijic, S.

published in Astronomy and Astrophysics, 429, pp. 631-643 (2005)

Abstract: HD 92024 is a member of the open cluster NGC 3293; it is the only eclipsing binary system with a ß Cephei component known in the southern hemisphere. This paper presents the first spectroscopic analysis of the single-lined binary and provides an orbital analysis based on recent high-resolution spectroscopy and photometry. A procedure to derive orbital elements with minimal influence of the pulsational line-profile variations on the radial velocities is applied, and we find the stellar masses to be 15.0+3.0-4.0 M? and 3.0±0.5 M? respectively, and radii of 8.4±0.8 R?, 2.1±0.4 R?. The temperatures are 25 500±500 K and 12 500±1000 K. The surface gravity values of log g= 3.77±0.08 and 4.27±0.18 indicate that the binary consists of an evolved early B-type primary and a late-B main sequence companion. The resulting distance 2.8±0.3 kpc and systemic velocity -16 km s-1 confirm cluster membership. Theoretical stellar models indicate an age of 10-13 Myr, somewhat higher than the literature value for the brightest members of NGC 3293. Based on observations made with ESO Telescopes at the La Silla Observatory, Chile, under programmes 66.D-0297, 67.D-0023, 68.D-028, and with the Strömgren Automatic Telescope, La Silla.

DOI: 10.1051/0004-6361:20041527
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