Short Period Pulsator Program

[Mike Foylan]

I am thinking of taking up CCD variable star observations which will be a new area for me. I had a look this evening on both the BAAVSS and AAVSO websites and there is a lot of excellent information, so much to choose from and so much one could do.
There is a program from the AAVSO however that catches my interest; called the SPP (Short Period Pulsator) Program which includes a number of RR Lyrae stars and a few delta Scutid stars with large amplitudes with some RR Lyrae stars that exhibit the Blahzko effect as well as some large-amplitude delta Scuti stars that have multiple periods. I am just wondering if anyone here has particularly interest / observed such stars over time and could offer advice in starting out and how best to contribute useful observations of scientific value.

Best wishes and clear skies

Mike
Cherryvalley Observatory (Code: I83)

[Jeremy Shears]

Hello Mike,

Good to hear about your interest in CCD photometry of variable stars. Indeed there is quite a bit that the modestly equipped observer can do in this field – especially when they combine data with other observers. The objects you mention are popular, partly because these they often have short periods which means you can get interesting data in a few nights. RR Lyrae stars, delta Scu stars and their cousins HADS (High Amplitude delta Scutids) fall into this category. I haven’t done much on these stars as I mainly concentrate on cataclysmic variables, which also have short periods (a few hours). A few of us looked at a delta Scu in Cas a while ago: http://adsabs.harvard.edu/abs/2007OEJV…76….1S. I have to admit the target happened to fall in the same field as a dwarf nova which was our main target!

I would be happy to chat a bit more with you about this topic – if you are attending the Meteor Section meeting in Birmingham on Saturday, that would be an opportunity (whilst talking about meteors as well, of course!).

Go well!

Jeremy

[Mike Foylan]

Hi Jeremy
Many thanks for your reply and for the link to your excellent work. Yes, it’s good starting out to see results from monitoring a known variable star over a short period of time as it gives one a chance to confirm results with published data. An added confidence to then explore more challenging objects.

I won’t be able to make it to the meteor section meeting this time unfortunately but I hope everyone attending has a fantastic time indeed.

Best wishes and clear skies

Mike
Cherryvalley Observatory (I83)

[Roger Pickard]

Hi Mike,

Sorry for the tardy reply.  We’ve been away for several days.

You ask about Short Period Stars and I can confirm that the VSS has no official RR Lyr or Delta Sct programmes as I’m sure you’ve noticed.  However, as Jeremy points out, that doesn’t stop some of us observing such stars from time to time.  Indeed, I’ve been following a number of HADS in a programme run by Patrick Wils:-https://docs.google.com/spreadsheets/d/1oGA2HaEHE8L6eX19ZoHqQQTu0LYV56HX3Srg7oCtOHo/edit?hl=en&pli=1#gid=5

I particularly like these stars because they are generally easy to observe (although quite frequently you need to find your own suitable comparison stars, but I can help you with that if necessary).  They are also mostly quite bright and are great to observe when conditions don’t allow the observation of fainter objects.

If you wish, we can chat more about this via email (roger.pickard@sky.com)

Cheers,

Roger

[Mike Foylan]

Thank you Roger for your reply and information regarding the HADS programme looks interesting indeed.

My main area of interest is minor planet astrometry and photometry (using either R or V Bessel filters) of which Cherryvalley Observatory submits results for publication to the Minor Planet Centre and the Minor Planet Bulletin.

The interesting thing about monitoring asteroids in this way is that on occasions a known variable star is within the field of view (sometimes for two or three hours) and that being the case there is four years of data on the observatory’s computer just waiting to be analysed for VS’s. I have to admit that I avoided such stars deliberately so as not to skew the photometry results of the asteroid under observation.
Now there is a realization of doing both VS’s and asteroid lightcurves, it’s an extra workload but could prove to be interesting. I look forward Roger to contacting you soon.

Best wishes and clear skies
Mike

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