Observing variable stars

Most clear, or nearly clear nights, you will find me out in the garden with a telescope frantically pointing it at star after star. It's not that I'm some sort of demented celestial tourist. What I'm doing is making an estimate of the brightness of particular objects in the sky. I'm also trying to estimate as many as I can, whilst making sure that my measurements are as accurate as possible.

I'm nowhere near as fast as the top flight observers like Gary Poyner, Mike Simonsen and Gene Hanson, but I can manage about one estimate every three minutes (which includes finding the object and recording the result). In an average night I'll make 50 to 60 estimates, which I guess isn't too bad.

What objects do you observe?

My observing program includes a wide range of objects from distant quasars to slowly pulsating red giants. Just over 150 objects in all. The bulk of the objects I observe are either cataclysmic variables in the Recurrent Objects Program of the BAAVSS, or objects which have been discovered by Mike Collins, and about which little is known.

Why bother when the Hubble Space Telescope can do it so much better?

The study of variable stars is one of the last bastions of the amateur scientist. Whilst it is undeniable that any professional instrument can out perform an amateur with a Mk1 eyeball, the fact is that the numbers of professional telescopes are limited.

Professional observatories cannot observe large numbers of objects on every available night; they cannot observe objects in the hope that they will do something interesting at the appropriate moment; and they will not undertake studies, sometimes lasting decades, without being sure exactly what they will be getting from the data at the end.
The observers of the British Astronomical Association Variable Star Section; the American Association of Variable Star Observers; the Warren Astronomical Society Variable Star Observers ; and The Astronomer, do all of these things and more.

We:

• Discover new objects for the professionals to investigate.
• Monitor new discoveries to give professionals information about the type of object that it might be.
• Monitor objects which behave erratically, so that the professionals can target their work when the object is behaving in the most interesting way.
• Monitor objects over very long time scales. More than a century of good quality data is available for some objects in the BAAVSS and AAVSO records.

Many of the worlds largest telescopes, including the great orbiting observatories like HST and Chandra, have objects identified and monitored by amateurs within their observing schedules. It is also far from unusual for them to be interrupted in other work to observe an object in response to the work of amateurs.

Why do I observe variable stars?

Because I'd like to feel I'm part of mankind's efforts to discover and understand the universe he lives in.