MBCAA Observatory

VX Hya (2011-2012 season)

Observed: 21, 22, 27 Feb, 13 Mar 2012

Michel Bonnardeau
6 July 2012


Time-series are presented for this pulsating star, after its sudden pulsation change in 2008 and after the 2010-2011 season observations.


VX Hydrae is a pulsating star with two main pulsations (periods of 5.36h and 4.15h) and multiple periodicities from the harmonics and beats. In 2008 it underwent a pulsation change.

In 2011 I observed its pulsations to be about 8mn late.


The observations were carried out with a V filter and with the same equipement as in the previous seasons and the photometry was performed the same way, e.g. see the 2008-2009 season.

244 images were obtained. For the check star, the average 1-sigma statistical uncertainty is 0.015mag, and the standard deviation is 0.020mag.

Comparison with the model

The observations are modelled the same way as in 2010 with a fundamental (1,0), an overtone (0,1), 2 harmonics (2,0) and (0,2) and 2 beats (1,1) and (-1,1). The parameters are those for the 2010 DSK observations.

The observed light curves are 15mn late from the model:

Red line: the model, Green dots: the observations.

Astronomical notes

VX Hya (2010-2011 season): the observed light curves are 8mn late from the same model.

VX Hydrae: observation of a sudden change in a pulsating star (2009-1010 observations and publication).

VX Hya (2008-2009) phase variations.

VX Hya (2008) free fall?.

VX Hya long term variability (with 2006's observations).

VX Hya time keeping (2005's observations).

Pulsating stars and the links therein.

Technical notes

Telescope and camera configuration.

Computer and software configuration.

Data processing.

Site map


Copyright notice

My data are available from HERE.
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