The eclipsing variables, TZ Corona Austrini, V Tucanae, RS Leporis, ST Carinae.

Abstract

view Abstract Citations (5) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The eclipsing variables, TZ Corona Austrini, V Tucanae, RS Leporis, ST Carinae. Wood, Frank Bradshaw Abstract The following systems were selected for observation because the published data assigned them the following characteristics: Algol-type light curve, spectral class A, periods of from 17 to 30 hours, and deep primary eclipses with duration from 3 to 6 hours. The short periods mean either extraordinarily large masses or small distances between the components. Similar systems which have undergone detailed analysis have shown normal masses for the brighter components; this, plus the short period, calls for a distance between components so small that the radii of the brighter components can only be about X2 those of normal A stars; this in turn locates the A components below their normal place in the HR-diagram. The secondary components in such cases have frequently been found to fill the limiting Jacobian surface and hence are in an interesting evolutionary stage. Lack of appreciable light change between eclipses, in such close systems can be most simply explained by a large mass-ratio. If this explanation survives detailed analysis, the fainter components of these systems must have abnormally low masses. The photoelectric light curves obtained of these four stars in general confirm the earlier photographic work, and are now being subjected to detailed analysis. The chief features of the different systems follow. Attention is called to the importance of spectrographic observation. TZCrA New:JD2436o8o.o35 +0d68674954 E.There is no strong evidence for change of period. Depths of eclipse: yellow 0.73 mag., 0.12 mag.; blue 0.73 mag., 0.10 mag. Secondary is central; light is nearly constant between eclipses; there is some reflection effect. There is some suspicion of intrinsic variatioi~. The eclipse is probably partial; duration - 0d14 = 31 22u1. UTuc New:JD2436i39.142 +o.87091649E. There is no evidence for change of period. Depths of eclipse: yellow 2.40 mag., 0.11 mag.; blue 2.84 mag., o.o8 mag. Secondary is central; light is nearly constant betweei~ eclipses, but third quarter is 0.05 mag. lower than first. There is suspicion of intrinsic variation. The eclipse is probably partial; duration - 0d18 = 411 19m. There is some reflection effect. 1?SLep New:JD2436I9I.I48 + I.2885439E. The period has apparently been constant during the interval in which the system has been observed. The curve is Algol type. There is a constant phase of about 25 minutes duration. Depths of principal eclipse: yellow 1.4 mag.; blue 1.7 mag. Duration = 0d22 = 5h I7~. ST Car This does not show an Algol-type curve, but exhibits appreciable curvature between eclipses. Ranges are 1.14 mag. and 0.32 mag. in the yellow and 1.18 mag. and 0.28 mag. in the blue in primary and secondary respectively. Flower and Cook Observatory, University 9J Pennsylvania, Philadelphia, Pa. Publication: The Astronomical Journal Pub Date: 1959 DOI: 10.1086/108044 Bibcode: 1959AJ.....64S..56W full text sources ADS |