Counting Stars to Measure Light Polution

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dream_mas
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Counting Stars to Measure Light Polution

Post by dream_mas »

I read that you can count the stars in your sky to measure the level of light polution you are experiencing. This makes sense but the article I read gave no basis for comparision.

I live in SouthWest Central Florida, Just below Tampa Bay, This past Friday, November 9th 2007, under a clear cool sky around 1am I counted 98 stars.

I am wondering where 98 stars would fall in measurement of light pollution based on star counting.

Any takers on this?
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Hawk
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Post by Hawk »

I think you're supposed to count a number of stars in a given constellation. i.e. How many stars can you see in the constellation of Orion, or how many stars can you count in the square of Pegasus? This will give you a better guide to the levels of light pollution in your area. :wink:
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RL Astro
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Post by RL Astro »

I've heard of counting stars in the Square of Pegasus before but I think your eyesight plays a large role in it as well as light pollution. You might just be able to see 5 stars in the Square but someone standing next to you might see 30 odd.
Also counting the stars in your whole sky might be a bit tricky if you can see the band of the Milky Way :wink:

S2
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Post by S2 »

The "Great World Wide Star Count" has a couple of examples of how to do this, for Cygnus in the NH and "the Teapot" in the SH.

Sorry to say this, but 98 doesn't really sound a lot. :(

nibor
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Post by nibor »

Hi dream_mas.
Take a look at this site
http://tinyurl.com/2czxdo
You may find the answer to your question here!
Rob

carlos dfc
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Post by carlos dfc »

Another way is to scrutinise a star chart, to see what is the dimmest star you can see, within a given constellation.

I use Ursa Minor when it is 'above' the Pole - and Cassiopeia when Ursa minor is below thw Pole.
(You'll always see more stars high above you, than when a constellation is low in the sky.
Dimmest star you can still see, gives a good estimation of you NELM (unaided-eye-limiting-magnitude)

I get about 4.2 - 4.5 from my back garden :cry:
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