Using optical aids

Hi Torngac !!! In my own personal experience, Ive made variable star estimates using telescopes, binoculars and naked eye observations. I believe all are acceptable for data, just make sure you list or log the way that the observation was made on your estimate sheet. Example - Observation made by naked eye or Binoculars etc.. Unfortunately Ive not made many estimates on variable stars :( but have an extreme interest and also work in the field of Astronomy. Listed below is an article from Sky & Telescope for bright stars available to watch for and make naked eye observations on. Also have you heard of the Galileoscope a nice quality low cost telescope kit that's available. If I've missed any details, Im sure others will help out. Good Luck and Thanks for your question !!! Listed below are the links :-) Have a great weekend.http://www.skyandtelescope.com/observing/objects/variablestars/3304276.htmlhttps://www.galileoscope.org/gs/~~~ PJ Goldfinger aka Spaceblanket :-)

Goldfinger is right on. You can use almost any type of optical aid. But there are some gotchas to watch out for. Mainly, avoid filters. This includes color, UHC, Oxygen, H alpha, etc. When you use a filter with visual observing you are transforming your eye's spectral response (basically you are cutting off areas the filter blocks) so your visual observation can no longer be compared with other people's visual observation. But if you stay away from filters then you can use opera glasses, binocs (my personal favorite), telescopes, etc. Most of the stars in our 10 StarTraining Manual drop to beyond magnitude 4 in brightness. This means that those in very ligh polluted areas may not even be able to see them when they are dim. In those cases, one can use binoculars to find them. Or you can just wait for them to "reappear". Side note: The world is much different with photometric observations. For them, filters are a must!

I would use no more than binoculars. The reason is that you would like the comparison stars to be either in the same field of view (they will be naked eye) or nearby, as they would be in a pair of binoculars. Binoculars would also be very helpful in a light polluted area. Using a telescope will give you a much narrower field of view, making it difficult to locate and use the comparison stars. Also, and this is important, a telescope can be over-kill on a bright object like Eps Aur. You may often times estimate the star brighter than what you would in binoculars and naked eye.Chris Stephan

Another consideration is to be consistent for a given observing program. For the reasons Chris mentioned, if you observe with your eyes one night, and a telescope the following, the brightness may vary due to perception vice something intrinsic to the star itself. The more variables (not stars :))you introduce to an observation, the more noise you introduce to the sample. Everything counts in large amounts. Every time you observe in a consistent manner, the better you'll get, and the more likely you will notice an actual change.

Hello Experience has shown that one can make the most accurate visual estimates about 2-3 mag above the limiting mag. If the var is much brighter or much fainter, the accuracy might and usually will actually suffer a bit. So its best to choose an optical aid that brings the var in this range. If one has regularly mag 6 LM or at least mag 5 LM skies, one should be able to observe eps Aur also in totality with the naked eye. If one has regularly worse conditions than this (e.g. due to light pollution, but also due to bright moon or twilight), it might be better to start right away with a (very) small binocular and make all estimates of eps Aur with the same optical aid. Oneissue is thatif one changes the optical aid (or even just the magnification significantly), one might get an "offset" in the estimates with the different setups. With mira stars and their pretty large amplitudes one can usually not avoid changing the optical aid or at least the magnification. As this setup dependent "offset" cann't be corrected for easily, its recommendable to make a few estimates with both aids/magnifications in parallel. Then a data evaluator can later correct for the offset in the evaluation. To do so its of course essential to add a comment to the estimates describing which aid and magnification one used for the estimate. Adding something like "naked eye" (aka 1x2 or 1x3 for non-dark adapted eyes to 1x5 to at most 1x9 for dark adapted eyes) or e.g. "6x30" for a 30 mm diameter, 6x magnifying binocular is already sufficient. As the amplitude of eps Aur is not very large, its possible and probably the best solution to choose a single optical aid that allows one to observe it under good conditions in maximum light and under bad conditions during totality and stick with it for all estimates during the campaign. CS Wolfgang

Hi Aaron

Did anybody ever try to make visual obs with an additional V band filter ? Do you know of any study in this area ? Usually it might not give much of a benefit. But with very red stars and/or comps it might reduce the differences and scatter due to the differing wavelength dependent perception of the differnt observers. Well populated LCs of single observers might not benefit much from it as their personal "system" can and often is pretty consistent. But it might have a significant effect on "collection" LCs like in the AAVSO LCG that regularly show a 2 mag scatter band with very red miras stars (about spectral class M5 and redder). CS Wolfgang