The weather is teasing me today
After a cloudy morning\afternoon, it quickly cleared at ~17 hours. The sky became great and the sunset was beautiful (I will post some images later). But soonly, as it got dark at 18h. Sc/Ac clouds started to move quickly from S, so the sky became completely cloudy (with some gaps). I tried to observe lunar occultation at 19:15, have seen the star (HIP24252) in 5 minutes before an occultation, but then the thicker cloud arrived and I lost the star from view.
Also tried to find the comet with binoculars through gaps, once I have found delta Cancri, but 6-7m stars near the comet weren't visible (through the edge of upcoming cloud). Now it is getting worse. All my hopes are for the next night...
I'm not sure how you guys measure with arc minutes and such, but on the 24th the comet filled the whole FOV in my eyepiece which is 1 degree I think, but tonight was barely detectable with 1/3 the size of my previous observation.
Let me tell how I measure the comet diameter in minutes.
One way is to precisely know a FOV of each of yours eyepieces (see below). Next move the comet to the edge of the FOV and estimate its size or just mentally divide FOV into 1/2, 1/3, 1/4, 1/10 etc and compare to the comet.
Another way is more precise. Find two closest stars to the comet, imagine the comet between them (or maybe it is already there) and again, estimate the comet's size regarding to the distance between the stars (1/2, 1/3,...). It is even better to repeat the estimate with another pair of close stars, if possible. Next, measure the distance between stars in software and convert your "1/2" into arcminutes. I prefer to use this method, it usually gives me enough good quality (+/- 1'), if only the comet is steadily visible.
A bit offtopic: how to define precisely the FOV of an eyepiece?
If somebody knows a formula, please post it, it will be much useful
Defining it in experimental way is not such precise but easier in some cases. Tonight I observed the Moon (dia. 32.8') at 56x, and the FOV was ca. 3% bigger than the Moon diameter. So, it is 34' (+/- 1').
I used the same method to define binocular's FOV, it was less precise, of course.
