Few Comments Regarding Low Amplitude Stars

I want to take a few moments at the end of this chapter to discuss the importance of observing two classes of variable stars that we've examined: eruptive and rotating variable stars. The majority of these stars display small amplitudes, therefore they require instruments to properly study and as a result may be ignored by many amateur astronomers.

The need for instruments shouldn't be viewed as an obstacle or a reason to believe that the proper study of these stars is beyond the capabilities of amateur astronomers. On the other hand, the study of low-amplitude variable stars is certainly not mandatory. There is no rule that requires visual observers to purchase the equipment needed to study these stars. As you should understand by now, there are a sufficient number of variable stars to keep the visual observer busy for many lifetimes providing valuable information. Visual observers should feel no pressure to begin using instruments.

With that said, what I would like to point out is that many amateur astronomers with instruments, meaning CCDs and photometers, are observing well-studied stars to a level not really necessary and could better use their precious time and turn their equipment toward the study of these poorly observed stars. I've noticed that within several variable star databases the brightness estimates for many fast, low-amplitude variable stars are spaced days apart. I want to be clear on this point so let me say it another way; a large number of these low-amplitude stars display fast changes in amplitude, on the order of minutes to hours, but the estimates reported are taken once every few days and so completely miss the important characteristics of the star. This kind of reporting fails to provide the kind of information needed by other astronomers and will not provide you with the necessary information base to conduct meaningful analysis of your own data. When you make reports like this you are failing to optimize your time. Fast variables, those experiencing changes in brightness over the course or minutes to hours, need to be monitored frequently, usually every few minutes throughout a complete cycle if possible. Think of it this way, if you wanted to understand the annual temperature changes for your geographical location, you wouldn't record the air temperature once a month and then predict the temperature extremes for the whole year, would you? Or check the stock index once a month to determine which to buy or sell? Of course you wouldn't. Don't do this when observing variable stars.

Chapter 7

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