Mon, 12/28/2015 - 19:15
Hello!
I am a relatively new observer. I did some visual observing for the citizen sky campaign a few years back. I am growing interested in getting back into visual observing, and I was looking around for a project. I am wondering if there is some scientific value in finding stars that are listed as NSV, or "newly suspected variables" in the binocular sweet spot of 5-9 mag which have very few to no observations. I feel like this is something I can do fairly easily, and such stars don't get swept up in the all sky surveys. Let me know if this sounds like a event idea, and any advice anyone has is perfectly welcome.
Thanks,
James Chase Geary, GJCA
In a recent class (Developing an observing program) the value of continuing to observe, and extending the light curves of, well-known and established variables was presented. This appears to be the desired direction for visual observers. That being said, I understand the appeal of your idea. However, and I hope someone with a better grasp of this will jump in if I am mistaken, most NSV stars if ultimately proven to be variable will not be types suitable for visual observing. If a star shows the type of variability (periods and amplitudes) that would be obvious to the visual observer, it would probably be classified and established quickly. I suspect most NSV types will require photometry or other instrument-based monitoring to determine their nature. That is not to say there might not be a few visual gems in there, but the percentage is probably low.
William Clarke. CWP
I fully agree with William.
There is hardly any bona-fide variable among binocular NSV stars.
I recommend the bright variables in the AAVSO Binocular program. Some of them are easy to follow and some are of great scientific interest.
Good observing,
Sebastian.
One of the best stars you can follow is CH Cyg. At the moment it's around mag.7 but its variations are very complicated - 'normal' red star behaviour (fairly slow variations, observe typically once a fortnight) appears but the CH Cyg system is a symbiotic variable (basically two stars feeding off each other!) and there is also short-term variation known as flickering. Add to this the fact that the system is eclipsing as well... and you have a star that is not only interesting to follow but important astrophysically. Lots of papers on CH Cyg that acknowledge amateur observations. Oh yes... it's circumpolar too!
I'd also suggest AB Aurigae. This is a forming star with a disc or shell of gas from which planets are being made. Like CH Cyg, it's around magnitude 7 at the moment but occasionally and unpredicably it will fade to beyond 8th mag. If you have good large binobulars you will notice that AB is a double star. The companion is SU Aur, another object of the same type, though fainter around mag 9 to 10.
One useful thing binocular owners can do is to follow Mira and SRa stars around maximum. Owners of large telescopes will avoid these phases (at least I hope they will) because a star that appears too bright in your eyepiece will tend to give inaccurate results. Anything above 10th mag I tend to leave alone. But that domain will be best suited to you. Just have a look at the predictions for Mira stars and note each month which suitable ones are at or near max. You can follow them until they fade from view. For example, I can remember following R Virginis with a 7x50 finder down to about mag 10.5
My method to find useful bino-variables with only one preparation once a year:
I have one binder with typical Bino stars like Z UMa, CH Cyg, R CrB, ...
I have a few binders with A and B charts for Mira stars, sorted by constellation (only the ones easily visible from Belgium). In front of each constellation I have a print with the yearly predictions. When outside, I just look up, see which constellations are visible, and observe the Miras that should be bright enough.