Stockert 1612 MHz monitoring of OH/IR stars


Last observations implemented: 2018 November

These pages document the progress of OH 1612 MHz maser monitoring program with the Stockert Radio Telescope carried out since 2017. Some test observations were made in 2016. It complements the NRT monitoring program of OH/IR stars, by observing stars with peculiar lightcurves. These stars have periods longer than 3 years and need to be observed over several cycles to determine the mean shape of the lightcurve and to determine amplitude and period variations.

On the main sequence, these stars had masses of 3-8 solar masses. They have lost most of their mass during the current evolution on the Asymptotic Giant Branch, with current masses <1.0 solar masses. They will loose their regular pulsation within the next few thousand years and will start developing into a Planetary Nebula and later into a White dwarf. Examples are OH 27.0-0.4 and OH 31.0-0.2, where nowadays only small scale fluctuations are observed.

Collaborators: W. Herrmann, D. Engels, and S. Etoka.



1612 MHz OH maser lightcurves [Jy*km/s]. Crosses: NRT observations. Blue squares: Stockert observations.
The model asymmetric sine-curves are eye-fits to the 2008 - 2012/2014 data and should only be used to guide the eye.

Lightcurve
Lightcurve
Lightcurve
Lightcurve
Lightcurve
Lightcurve
Lightcurve
Lightcurve
Lightcurve

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Last modification: Friday, 07-Dec-2018 11:00:10 CET | D. Engels