Studies of early-type variable stars. 6: Absolute parameters of the Algol system RZ Cassiopeiae
A new spectroscopic orbit is presented for the semi-detached eclipsingbinary system RZ Cas (HD 17138, P=1.195 days, alpha(2000.0) = 2 h 48.9m, alpha = +69 deg 38 min, (A3V+KO), based on Reticon observations withthe Dominion Astrophysical Observatory (DAO) 1.2 m telescope and coudespectrograph. We find: mp sin 3 i = 2.16 +/- 0.07solar mass, ms sin3 i = 0.715 +/- 0.02 solar mass(ap + as) sin i = 4.68 +/- 0.07 x 106km, mp/ms = 3.02 +/- 0.07. This is the firstdirect measure of the mass ratio for this system. The new mass ratio isused to solve the UBV light curves of Chabliss (1976) for the absoluteparameters of the system. These in turn are used to apply correctionsfor non-Keplerian effects to the spectroscopic orbit. Published times ofminimum demonstrate that a significant orbital period change occurredduring the time interval over which these spectroscopic observationswere obtained. This appears to be associated with changes in the spectraobserved during this time. We suggest that this is the result of aperiod of increased mass transfer producing a hot spot or accretionbulge on the surface of the primary component. Stroemgren uvbyphotometry and low resolution UV (IUE) spectra both suggest a spectraltype of A3V for the primary component and a surface composition similarto the Sun. DDO photometry of one primary eclipse of RZ Cas is alsopresented which appears to show composition anomalies in the secondarycomponent. The absolute parameters of the system are found to be:Mp = 2.205 +/- 0.075 solar mass, ms = 0.73 +/-0.02 solar mass, Tp = 8600K +/- 100K, Ts = 4700+/- 200K Rp = 1.67 +/- 0.03 solar radius, Rs =1.94 +/- 0.03 solar radius. The system is probably unreddened at adistance of 73 +/- 2pc.
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B and V photometry and analysis of the eclipsing binary RZ CAS
Photoelectric light curves of the eclipsing binary RZ Cas are presentedfor B and V filters. The light curves are analyzed for light andgeometrical elements, starting with a previously suggested preliminarymethod. The approximate results thus obtained are then optimised throughthe Wilson-Devinney computer programs.
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The Totality in a Primary Minimum of RZ Cassiopeiae
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Recent Photoelectric Minima of the Eclipsing Binary RZ Cas
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H-beta photometry of northern intermediate galactic latitude early-type stars and galactic structure away from the plane
Photoelectric H-beta photometry is presented for 255 early-type stars atintermediate galactic latitudes. Absolute magnitudes and distances arederived for the more luminous stars. Those with visual magnitudes lessthan or equal to 2.5 and at distances of up to 1 kpc from the galacticplane may follow the spiral structure in the plane.
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UBV photometry and MK spectral classification of northern early-type stars at intermediate galactic latitudes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977MNRAS.180..691H&db_key=AST
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Photoelectric Times of Minima of RZ Cas
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Period variations of the eclipsing binary RZ Cassiopeiae.
Abstract image available at:http://adsabs.harvard.edu/abs/1974A&A....30..259H
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The Light-curves of Eclipsing Binaries
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Observations photoélectriques
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Observations photoélectriques d'étoiles variables
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Photographic light-curve of the variable star SU Cassiopeiae.
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