Observations of PS1-3PI J000743.48+803318.0

 The star PS1-3PI J000743.48+803318.0 is a variable of the RRAB type, according to VSX.

This is a rather faint star and, probably, near the limit of my setup (150mm Newtonian with a focal length of 750mm).

The star is located in the V965 Cep field, which I observe regularly. For measurements, I used stacked images with a total exposure of 10 minutes (usually, stacks of 20 images, 30 seconds  each).

The following phase diagram presents observations from July 2022 to April 2024.

These are "Unfiltered with V Zeropoint" magnitudes.

Comet 12/P Pons-Brooks

Comet 12/P Pons-Brooks low on the horizon.
07 Apr 2024 ~18:01 UT, Kyiv [21:01 local time].
Canon EOS 600D, lens f=50mm.
Stack of 20 frames (3.2 sec each)

 

 

 

A New High-Amplitude GDOR Star PMAK V136

After a long pause when all my new findings came from data mining, I eventually found a new variable star on my own digital images.

The star is registered as PMAK V136 in the International Variable Star Index (VSX): https://www.aavso.org/vsx/index.php?view=detail.top&oid=2388114

It is a Gamma Doradus-type star (GDOR) whose variability is caused by asteroseismic oscillations. In most cases, the variability range of such stars does not exceed 0.1 V. My observations (clear filter) show the amplitude of 0.1 mag. However, there is evidence that GDOR stars may show a variability range well above the 0.1 limit (see, for example, 2020MNRAS.499.3976P). Such High Amplitude GDOR stars (HAGDOR) oscillate on several close frequencies; beating between those frequencies may give higher amplitudes. It seems that PMAK V136 is such a HAGDOR star: ZTV g variability range is 0.25 mag.
 

I thank Sebastian Otero for his help in the classification, advice, and tips.

 

 

Reports at the XXIII Gamow International Astronomical Conference

TESS SURVEY AND THE MYSTERY OF AN ELUSIVE ECLIPSING VARIABLE STAR NQ HERCULIS

 

 

OBSERVING VARIABLE STARS AT THE "OSOKORKY" OBSERVATORY