(meteorobs) Re: The Bortle Dark Sky Scale and meteors?


I feel that your suggestion is an excellent idea. I know for a fact that
my observing sites, especially at home, are rated less than perfect on
the Bortle scale yet I am still able to perceive faint stars. I feel
that this added information could help determine an observer's
perception. Probably not in a exact mathematical sense but enough to
categorize a person as having above or below average perception.

It would be interesting to see if those claiming to have a LM near +7.0
also possess a high rating on the Bortle scale. On the other end of the
spectrum it would also be interesting to see the ratings observers
estimate from home under LM's near +5.0 and worse.

The Bortle Scale is not available on line but is published in the
February issue of Sky & Telescope. For those who do not subscribe to Sky
& Telescope a copy of the February issue should be available is any well
stocked library.

I would encourage all observers to attempt to use the Bortle scale in
addition to your normal limiting magnitude estimates and to share your
results with others.

Clear Skies!

Robert Lunsford

Lew Gramer wrote:
> A recent thread on a regional astronomy mailing list I belong to mentions
> the excellent article by John Bortle in Sky & Telescope's Feb 2001 issue.
> Many of our readers may have seen the article already. However, for those
> who have not, it argues (rightly, I think) that the Limiting Magnitude and
> other traditional measurements of sky darkness simply fail to accurately
> reflect the visibility of deep-sky and other extended objects. In place of
> these traditional measurements, Bortle presents a simple 9-step scale for
> sky darkness, based on the observed visibility of various specific objects
> and classes of objects, both in the sky and on the ground near an observer.
> My question for 'meteorobs' is this: Although the Bortle scale clearly can
> not and should not ever replace Limiting Magnitude as a calibrating factor
> for visual meteor observations, should meteor recorders in fact begin to
> record the Bortle Scale of the skies under which they observe meteors? The
> argument in favor of this is simply that one can never forsee what value a
> piece of data might hold for future research. And something which purports
> to measure the "quality" of the sky, may some day be useful for those who
> wish to allow the PUBLIC to know what to expect from meteor showers.
> The argument against this, obviously, is that meteor observers are already
> asked to collect a good number of different data items, both about their
> observing conditions and about individual meteors. Adding one more without
> definite good reason may not make sense.
> I'd be interested to hear the opinions of our readers on this!
> Clear skies,
> Lew Gramer
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