[Prev][Next][Index][Thread]
(meteorobs) Limiting magnitude
Let me tackle the limiting magnitude problem: First, from the theoretical side:
An observer not looking at the zenith should see less meteors than somebody
looking to the zenith because the meteors are farther away and, hence, fainter.
However, it turned out that the loss due to larger distance plus extinction
approximately balances the increased volume the observer looks through (and sees
more meteors in therefore). This would mean that the limiting magnitude should
not contain the extinction, i.e. it should be estimated in the zenith. (This is
also what the Visual Handbook says in paragraph 2.5.2.)
Now for the practical side: You know extinction can vary greatly. Moreover, star
count areas are not in the zenith generally. So you may use any fields down to
50deg without problem. And please don't start another discussion because you
once chose a field at 40deg elevation---it's ok (extinction is about .1mag
there). If it is really hazy and you endeavour to observe, you will
automatically choose a field close to the zenith where the sky is best, and you
will not have the problem with an incorrect balancing as said above.
Rainer
Follow-Ups: