Variable star V544 Andomeda

[Dave Smith]

Unexpectedly clear last night so had a go at a different HADS star. The graph here is the output from AstroImageJ that I now use for the photometry. The horizontal lines are the 3 comparison stars.

Dave

[Alan White]

Dave

Is this varying in magnitude quickly, or am I misreading the graph.

[Dave Smith]

9 minutes ago, Alan White said:

Dave

Is this varying in magnitude quickly, or am I misreading the graph.

Hi Alan

The time scale is in days.  So the period for this star is just over 2.5 hours. The change in brightness is due to the expansion and contraction of the star.

Dave

[Sunshine]

3 hours ago, Dave Smith said:

The change in brightness is due to the expansion and contraction of the star.

When you say expansion and contraction, do you mean this star is in its death throes? core collapse?

[Dave Smith]

8 hours ago, Sunshine said:

When you say expansion and contraction, do you mean this star is in its death throes? core collapse?

No that is not right. The best explanation I have found is here https://www.aavso.org/vsots_delsct

Especially half way down the page on "What makes them tick?"

Dave

[JOC]

Those results look most professional - really impressive observations, I'm not entirely certain what sort of kit takes those readings, but it's a really neat set of results - just the sort of thing I can imagine you being into.  Maybe one day I'll have to visit and see the kit you have!

[Dave Smith]

Thanks JOC. I have recently upgraded my kit but most of the variable star work I have done has been with a 90mm refractor and CCD camera. In order to get to fainter stars I am now using an 11" EdgeHD scope. This star varies from around mag 13 to 13.6.

You are very welcome to visit anytime. Email on it's way.

Dave