The eclipsing system, SZ Psc.
Abstract
At the David Dunlap Observatory, 30 spectrograms and 210 two-color photoelectric observations have been made of the Algol-type eclipsing variable SZ Psc. A new epoch of primary minimum has been established, J.D. 2436114. ~6~. Rugemer's period of 3.96637 days satisfies our recent velocity and light observations, but no period has been found which reconciles these with our four 1939-40 velocity observations and with earlier photometric observations by others. Two spectra are visible, making possible classification KI IV-possibly V but not 111-and F8 V and estimation of relative luminosities (Bx BF). Bright H and K lines in the spectrum belong to the K star. The velocity curves give Kx= 82km/sec, mx+m~sin1~=2.93O, KF = 110 km/sec, mx/m~ = 1.34. a sin ~= 10.5X106 km, The light curves give B = 8.69 and V = 7.72 for the primary minimum and B = 8.10 and V = 7.30 for the secondary. The average values for the maximum are B = 8.02 and V = 7.22, but there is so much scatter that intrinsic variation of one of the stars is suspected. The width of primary minimum is about I I per cent of the period. These data are consistent with the following description of the system: Principal eclipse an occultation of the F-star and nearly total. Inclination 810. Diameters: KI, 4.00; F8, 1.60. Masses: KI, I.7O;F8, 1.30. Absolute photographic magnitude of each component: ~3.6. While these figures must be regarded as tentative until the light curves are more complete, there is no doubt that the larger, cooler star is the more massive. Barring supergiant systems like 32 Cygni, this is contrary to the rule for all other Algol-type systems with appreciable differences in the spectral types of the components. David D~nlap Observatory, University of Toronto, Richmond Hill, Ontario
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 1958
- DOI:
- 10.1086/107661
- Bibcode:
- 1958AJ.....63Q.302B