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Results are presented from an analysis of observations in a sample of 53 long-period pulsating stars (44 of which are Mira-type
and 9 are semiregular variables). A catalog of the characteristics of the individual pulsation cycles of the light curves
is obtained for these stars. A correlation analysis of the characteristics of the individual pulsation cycles is carried out
for each star. A number if diagrams relating the variability of the characteristics of the individual cycles to the average
parameters of the variability of the stars and to their spectral classes. New criteria for classifying long-period variables
are proposed on the basis of these diagrams.
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Translated from Astrofizika, Vol. 49, No. 4, pp. 595–612 (November 2006). 相似文献
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The results of 27 h of time series photometry of SDSS 121209.31+013627.7 are presented. The binary period established from spectroscopy is confirmed and refined to 0.061 412 d (88.43 min). The photometric variations are dominated by a brightening of about 16 mmag, lasting a little less than half a binary cycle. The amplitude is approximately the same in V , R and white light. A secondary small brightness increase during each cycle may also be present. We speculate that SDSS 121209.31+013627.7 may be a polar in a low state. 相似文献
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M. R. Truss 《Monthly notices of the Royal Astronomical Society》2005,356(4):1471-1476
The 2001 outburst of WZ Sagittae has shown the most compelling evidence yet for an enhancement of the mass-transfer rate from the donor star during a dwarf nova outburst in the form of hotspot brightening. I show that, even in this extreme case, the brightening can be attributed to tidal heating near the interaction point of an accretion stream with the expanding edge of an eccentric accretion disc, with no need at all for an increase in the mass-transfer rate. Furthermore, I confirm previous suggestions that an increase in mass-transfer rate through the stream damps any eccentricity in an accretion disc and suppresses the appearance of superhumps, in contradiction to observations. Tidal heating is expected to be most significant in systems with small mass ratios. It follows that systems like WZ Sagittae – which has a tiny mass ratio – are those most likely to show a brightening in the hotspot region. 相似文献
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