MBCAA Observatory

VX Hya (2010-2011 season)

Observed: 5, 7, 8 Feb, 4 Mar, 9 Apr 2011

Michel Bonnardeau
15 Feb 2011
Updated 5 Mar (more observations), 5 Dec 2011 (observations of April)


Time-series are presented for this pulsating star, after its sudden pulsation change in 2008.


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.


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

177 images were obtained. For the check star, the average 1-sigma statistical uncertainty is 0.012mag, and the standard deviation is 0.013mag.

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 observations and the model:

Red line: the model, Green dots: the observations. The observations may be 8mn late from the 2010 model.

Astronomical notes

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

The data were submitted to the AAVSO International Database, observer code BZU.

2011-2012 follow-up observations
MBCAA Observatory. Copyright 2004-2012