17,290 research outputs found
The dynamics of variable stars
Harmonics, pulsation amplitude, and vibratory motion of Cepheid variable star
Variable Stars: which Nyquist Frequency ?
In the analysis of variable stars, the problem of sampling is central. This
article focusses on the determination of the Nyquist frequency. It is well
defined in the case of regular sampling. However, the time series of variable
stars observations are generally unevenly sampled. Fourier analysis using the
spectral window furnishes some clues about the equivalent Nyquist frequency in
the irregular case. Often it is pushed very high, and thus very short periods
can be detected. A specific example is shown, drawn from MACHO databases.Comment: 4 pages, 5 figures, submitted to A&
Nine New Variable Stars in Camelopardalis
Nine new short period variable stars have been discovered in the direction of
the open cluster Cr464 in Camelopardalis. The field was observed using Tzec
Maun Observatory's telescope AP180. Two new variable stars were classified as
pulsating stars (RRab and RRc types). The other seven stars are binary systems.
One of them is of ELL-type, four binaries were recognized as EW-type, and two
systems are rather short period EA-type binaries. All new variables were
registered in the VSX catalogue.Comment: 8 pages, 19 figure
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