view Abstract Citations (10) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Spectrum of RX Cassiopeiae. Struve, O. Abstract The spectrum of the eclipsing variable RX Cas is composite, consisting of a gG3 component and a gA5e component. The two spectra are roughly of the same intensity at X 4000. Assuming that the tem- peratures are 5000 ° and 80000, the ratio of the radii k 0.257. The emission lines show the effect of ec'ipse, and the entire system resembles that of SX Cas. The velocity-curves from the lines of the G3 star give a symmetrical curve with P = 32.315 days, -y = -24 km/sec K = 36 km/sec, e = 0.00, T = phase of passage through y velocity = 30.3 days, a sin i = 1.6 X 10~ km, andf(m) = 0.160. This star is in front during the principal eclipse. The A5 star gives the velocity-curve of that component which is being eclipsed at principal eclipse: y = -3 km/sec, K = 34km/sec, e = 0.18w = 37 °, and T = phase of periastron passage = 30.3 days. The difference in y of the two curves is notable, perhaps also the larger eccentricity of the A5 star's curve. These discrepancies must be due to a distortion of the latter curve by absorption lines formed in the gaseous streams around the A5 star. These phenomena are similar to those observed in SX Cas. The radial velocities obtained from the H absorption lines show no periodic oscilla- tion. A rediscussion of the light-curve of RX Cas, using a series of observations by Martinoff, in conjunc- tion with the spectrographic data, leads to the conclusion that the eclipse thay be nearly grazing. The principal photometric elements are: k = 0.257, a~ = 1.00, ellipticity constant sin i = 0.7, duration of photometric eclipse = 4.3 days, duration of entire eclipse of gaseous streams = 5.8 days, inclination = 75o, aG 0.50, a, = 0.13, L. = 0.67 (in visual light), and LA = 0.33 (in visual light). The remark- able similarity of RX Cas and SX Cas is disturbed oniy by~the fact that in the former the total light of the G star predominates at all phases and in all spectral regions except the extreme violet, `whi]e in the latter the light of the A star predominates in all accessible spectral regions and at all phases except near principal mid-eclipse. Because of the distorted character of the velocity-curves of the A stars in both systems we have no information concerning the mass ratios Publication: The Astrophysical Journal Pub Date: May 1944 DOI: 10.1086/144621 Bibcode: 1944ApJ....99..295S full text sources ADS |