[Previous] | [Session 46] | [Next]
J. A. Mattei, G. Foster (AAVSO)
We have performed a trend analysis of 383 Oxygen-rich and Carbon-rich long period variables (LPVs) using 90 years of AAVSO data, as a continuation of our study of the long-term behavior of LPVs (Mattei & Foster 1997, BAAS vol. 29, no. 5, 46.08). We studied the period and amplitude, as well as the mean magnitude and asymmetry (time from minimum to the following maximum as a fraction of the period). Our analysis indicates that the period is a much more stable parameter than the others; longer-period stars are more likely to show period fluctuations than shorter-period stars. The light curve asymmetry is the parameter most likely to show a trend; 50% of the sample stars show some trend in their asymmetry. A significant fraction of the stars seem to be getting fainter in their mean visual magnitude, while a very small number appear to be brightening. Also, the Carbon-rich LPVs show significant differences in their light curve behavior from the Oxygen-rich LPVs. We point out a few stars that show extreme time evolution of their light curve parameters, many of which deserve detailed study.
If you would like more information about this abstract, please follow the link to http://www.aavso.org/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
The author(s) of this abstract have provided an email address for comments about the abstract: aavso@aavso.org