That is really interesting Alex. The 4.98 bucket star is a challenge to
see under most conditions.
On Sat, Jul 11, 2015 at 11:48 PM, Alex Vrenios <axv@xxxxxxx> wrote:
Almost all of the Astronomical League observing programs require you to
log time, date, location, etc., and something called “seeing.” Seeing
conditions are covered by two values: an estimate of the faintest star you
can not-quite-see, called transparency, and the steadiness of the
atmosphere, called seeing. (I lump the two estimates into what I call
“seeing.” Sorry for any confusion.)
I made this guide some time ago - probably saw it in a book somewhere:
Find the dimmest star you can see (after at least a 15 minute
dark-adjustment period) and then try to see the next dimmest (larger
magnitude value). Estimate seeing between the one you can see and the one
you can’t see.
Example: Three of the four “bucket” stars are visible but that upper
right-hand corner one (at 4.9) is not. Also visible is the star just down
and left of the two bright bucket stars, at 4.4. Average these two and you
get about 4.7, which is what you should log for transparency. You can check
a few more dim stars if you want to refine your estimate, but this is
sufficient.
Here in AZ I’ve never seen code III conditions, and I wouldn’t set up the
scope if it was code IV. Most of my log entries show level I (perfect) and
some show a level II (slight undulations).
Assuming the above, I’d report 4.7/I in my log entries for everything I
observe until the conditions change.
Note that there is another steadiness rating based on a 10-scale, but I’ve
been using this I-through-IV rating in my submissions to the Astro League
for some time now and they seem to be okay with it.
Hope this helps,
Alex
