Stargazing is fun, and a lot of people do it. But I have felt for a long while that you aren't doing astronomy unless you measure something or count something or time something. My log book shows that I made my first variable star observation on April 29, 1961, and it took me an hour and a half to locate the star - Z UMa. That's typical for a first try, but practice makes a difference. Today I can finish a visual observation in 5 minutes or less. A PEP (photo-electric photometer) observation, which involves 18 separate measurements, usually takes from 12 to 15 minutes even when the photometer is feeding a computer. Since that first night nearly 37 years ago I have submitted 11,533 visual observations and 4,208 PEP observations to the AAVSO, where they have been added to the over 8 million observations in their electronic database.

Last year, after seven years of photoelectric observations, I discovered that the semi-regular variable U Delphini had a long secondary period of 1100 days superimposed on the 100 day primary period. I wanted to see how far back this phenomenon could be traced, so I visited AAVSO headquarters in Cambridge and came away with a disk that contained 19,670 observations of the star going back to 1911. That made some light curve! In fact I had to write my own Basic programme to get a print-out of the graph. My usual spreadsheet wouldn't handle that many data points.

Friedrich Argelander, usually called The Father of Variable Star Observing, said, amongst other things, "Observations buried in a desk are no observations". So, if you feel like doing some real astronomy, measuring, timing or counting something is only the first step. The next step, and the most important, is to decide what you are going to do with your observation besides bury it. The obvious first choice is to publish it in Astrotent. I'm sure Ramesh would be delighted. But, fine as it is, Astrotent is limited in circulation. At which point I have to put in a plug for the AAVSO. Those 8 million plus observations have been mostly contributed by amateurs like ourselves, but they are available for the whole astronomical community, amateurs and professionals alike. Headquarters processes about 500 requests for data every year. Generally, over 30% of these are for multi-wavelength data correlation and scheduling of satellites such as HST, EUVE, IUE, ROSAT, XTE and ISO. This means direct participation in a very high-tech and professional branch of astronomy. What gives me a kick is the thought that our observations are not only being stored, they are being put to good use - maybe or maybe not my particular observations, but certainly those of somebody who's an amateur just like me.

Do you think of stars as constant, static things, bright specks in the eyepiece that you use for hopping to your galaxies, like stepping stones across a stream? Some of them are, but an awful lot are as individual as people, with just as many quirks and idiosyncrasies. These are the variable stars, and, like people, they come in different kinds and colours (and shapes!). The pulsating variables are literally pumping in and out like colossal celestial hearts. And even these come in different varieties. Some like the Miras pump slowly and with great regularity, having periods of about a year. On the other hand, the irregulars are like some people you and I know - you can never tell what they are going to do next. In between are the semi-regulars, pulsating in 30 to 50 days. If you like things to happen quickly, then the Cepheids and RR Lyraes will do their stuff in anything from a few days to a few hours. Another kind entirely are the cataclysmics which mosey along doing nothing in particular for weeks or months, until suddenly all hell breaks loose and they increase ten magnitudes overnight. Then there are the geometric variables, binary systems so orientated that they eclipse one another in our line of sight. These fade with the regularity of clockwork and you will find some with their periods listed to 6 decimal places of a day, and that's equal to a hundredth of a second. Yet if you time eclipses carefully and compare this with earlier records, you sometimes find the time of minimum getting out of sync because of changes in the orbital periods of the stars.

The rotating flat supplies azimuth elevation, while the entire scope rotates in bearings for tracking.

Through the years I have found that the constant changes in the variable stars I observe never fail to hold my interest. I keep light curves of some of them and there is always something going on either expected or unexpected. The main thing is that something is happening. Apart from novae (which are variable stars anyhow) have you ever thought of waiting around for something to happen to M31? You'd be awfully long in the tooth. Am I inviting everyone to join the AAVSO? Not really. It depends on how you look at amateur astronomy. You don't have to quit NYAA to do join another group; just fork out a few more bucks. There are over 30,000 variable stars listed, with more being discovered every year, plenty enough for all of us.