[Prev][Next][Index][Thread]

(meteorobs) Re: Meteor Activity Outlook for Aug. 3-9, 2001



Lew,

Thanks for the kind words.

Undoubtedly there will be a few observers out in the days preceding the
Perseid maximum under bright moonlight. Hopefully they will obtain
enough data to give us an idea of the pre-maximum rates. This is
entirely possible for observers who enjoy transparent skies with LM's
better than +5.0 despite the moonlight. 

My intent was not to completely discourage any observing. But for a
majority of the people who watch under murky, humid skies (if the skies
are clear at all!) watching under these conditions will result in very
mediocre activity.

There are some disagreements as how to compare data from observations
under moonlight to those under better conditions. One group feels that
the LM correction is all that is needed while another feels that an
additional "moonlight" correction is necessary. I believe this topic has
been discussed previously on meteorobs.

Clear Skies!

Bob Lunsford



Lew Gramer wrote:
> 
> A hearty & sincere "THANK YOU" to IMO Secretary General Bob Lunsford, for the
> wonderful service he continues to provide the amateur meteor community, with
> these weekly "Meteor Activity Outlook" postings. I know they are a lot of work
> to put together, and Bob should be assured that they ARE appreciated. (I for
> one read them religiously, and often print them to share with local groups.)
> 
> This week's edition of the Outlook did raise a question for me, though, which
> I thought might be worth readdressing. (As 'imo-news' is generally NOT meant
> for extended discussions of this kind, feel free to direct any response emails
> on the following topic to the address 'meteorobs@atmob.org'.)
> 
> The Outlook states that "With the intense moonlight practical meteor observing
> sessions are not possible this week." And of course, this statement is quite
> right under normal circumstances. When a bright moon is present, the observer's
> Limiting Magnitude will be quite low (and LM correction factor correspondingly
> high), and hourly rates away from the major peaks are often too low to provide
> statistically significant samples from individual visual observers.
> 
> However, with a sadly moon-blazoned major shower peak (PER) approaching next
> week, observers will be forced to record many hours in bright moonlight, on
> several nights running! Under such circumstances, the perennial question is
> bound to arise, of how moonlit observations can be compared with prior years'
> (dark sky) observations? Just as puzzling, how is a broad activity curve for
> this year's Perseid stream to be developed, based purely on observations on
> just one or two (possibly three) nights centered at the peak??
> 
> Does it in fact make sense, for SOME few observers to record the very low
> pre-peak rates the Perseids will display under bright moonlight next week?
> Maybe the answer is, "No, since there will be a wealth of POST-shower peak
> observations, as the moon wanes the week of 12 August." But I thought the
> question worth bringing up NOW, before observers worldwide finalize their
> observing campaign plans for the 2001 Perseids.
> 
> Clear skies all!
> Lew Gramer (GRALE), NAMN
To stop getting email from the 'meteorobs' list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html

References: