Observation of possible mode switching in three semiregular variable stars

1991 ◽  
Vol 101 ◽  
pp. 1043 ◽  
Author(s):  
R. R., Jr. Cadmus ◽  
L. A. Willson ◽  
C. Sneden ◽  
J. A. Mattei
Keyword(s):  
Variable Stars ◽  
Mode Switching ◽  
Semiregular Variable Stars ◽  
Semiregular Variable

scholarly journals Semiregular Variable Stars

Astrophysics ◽  
2019 ◽  
Vol 62 (4) ◽  
pp. 556-572 ◽  
Author(s):  
L. S. Kudashkina
Keyword(s):  
Variable Stars ◽  
Semiregular Variable Stars ◽  
Semiregular Variable

scholarly journals Mass‐losing Semiregular Variable Stars in Baade’s Windows

2001 ◽  
Vol 552 (1) ◽  
pp. 289-308 ◽  
Author(s):  
C. Alard ◽  
J. A. D. L. Blommaert ◽  
C. Cesarsky ◽  
N. Epchtein ◽  
M. Felli ◽  
...  
Keyword(s):  
Variable Stars ◽  
Semiregular Variable Stars ◽  
Semiregular Variable

scholarly journals Chaotic Behavior and Statistical Analysis of Some Mira and Sr Stars

1993 ◽  
Vol 134 ◽  
pp. 149-151
Author(s):  
T. Yanagita ◽  
H. Satoh ◽  
K. Saijo
Keyword(s):  
Statistical Analysis ◽  
Chaotic Behavior ◽  
Variable Stars ◽  
Light Curves ◽  
Semiregular Variable Stars ◽  
Semiregular Variable ◽  
Visual Light

AbstractVisual light curves of some Mira and semiregular variable stars are analyzed to search for their chaotic and statistical behaviour. Discussion are also given.

scholarly journals Mode Switching in Red Semiregular Variable Stars?

1995 ◽  
Vol 155 ◽  
pp. 405-406
Author(s):  
J. Gál ◽  
K. Szatmáry
Keyword(s):  
Variable Stars ◽  
Point Of View ◽  
Mode Switching ◽  
Radial Pulsation ◽  
Light Curve Analysis ◽  
Time Intervals ◽  
Frequency Spectra ◽  
The Mean ◽  
Semiregular Variable

AbstractLight curve analysis of the carbon variable RY Dra and the oxygen-rich variables TX Dra and AF Cyg is summarised. In each case, two shorter periods were found (which may be connected with the radial pulsation of the stars) and also a long term variation in the mean brightness. In the case of RY Dra, the amplitudes of the shorter periods both decreased while the amplitude of the long secondary variation was found to be increasing. The light curves and frequency spectra of TX Dra and AF Cyg can be interpreted as a result of mode switching. These stars pulsate with two different periods and there are time intervals when the longer period disappears and the shorter one remains dominant, and it lasts for many cycles. We concluded that the double and multi-periodic red semiregular variables may be very important from both theoretical and observational point of view, because, based on the ratio of the periods, we can identify the pulsational modes in these variables.

scholarly journals Aperiodic Ordered Sequences and Multiperiodicity in Semiregular Variable Stars

2002 ◽  
Vol 185 ◽  
pp. 568-569
Author(s):  
Juan García Escudero
Keyword(s):  
Light Curve ◽  
Variable Stars ◽  
Curve Analysis ◽  
Lindenmayer Systems ◽  
Light Curve Analysis ◽  
Fibonacci Sequences ◽  
Semiregular Variable Stars ◽  
Semiregular Variable

AbstractThe use of aperiodic ordered sequences described by Lindenmayer systems in the study of the strings of periods for multiperiodic semiregular variables is proposed. Fibonacci sequences play a central role in the light curve analysis of UW Herculis.

scholarly journals Period-Gravity Relation for Semiregular Variable Stars

2002 ◽  
Vol 185 ◽  
pp. 566-567
Author(s):  
K. Szatmáry ◽  
L.L. Kiss
Keyword(s):  
Variable Stars ◽  
Radial Pulsation ◽  
Giant Stars ◽  
Pulsating Variable Stars ◽  
Stellar Pulsation ◽  
Short Period ◽  
Red Giant ◽  
Rotating Star ◽  
Semiregular Variable Stars ◽  
Semiregular Variable

Red giant stars located on the AGB are intrinsically variable, which is usually associated with stellar pulsation. The complex light variation of semiregular variables (SRVs) has many alternative explanations. Besides the pulsation, other contributors to variability cannot be solidly excluded, such as time-dependent surface inhomogeneities, ellipsoidal deformation due to the presence of a close companion, or spots on a rotating star. The identification of ultra-short period M-giants with periods of a few days raised the possibility of very high-order overtone pulsation of these stars. Thus, it is very important to draw various constraints on the stellar pulsation in semiregular variables and to separate other physical causes. Here we present new empirical evidence for radial pulsation in SRVs through studying their period-gravity relation, following the ideas outlined by Fernie (1995, F95). F95 studied a log P versus log g relation for various types of radially pulsating variable stars. He found a well-defined linear relation, which might serve to test whether the pulsation is radial or nonradial and, in the former case, fundamental or overtone. The main goal of our study is to extend the relation into the domain of SRVs.

scholarly journals Evidence for Low‐dimensional Chaos in Semiregular Variable Stars

2004 ◽  
Vol 613 (1) ◽  
pp. 532-547 ◽  
Author(s):  
J. Robert Buchler ◽  
Zoltan Kollath ◽  
Robert R. Cadmus, Jr.
Keyword(s):  
Variable Stars ◽  
Low Dimensional ◽  
Semiregular Variable Stars ◽  
Semiregular Variable
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