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Full moon LP at dark site

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#1 gdd

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Posted 24 April 2013 - 12:32 AM

Does anyone know what the effect is of a full moon at dark site? It would be equivalent to what color of sky on the light pollution maps for a moonless night?

Thanks,

Gale

#2 Tony Flanders

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Posted 24 April 2013 - 04:19 AM

Does anyone know what the effect is of a full moon at dark site? It would be equivalent to what color of sky on the light pollution maps for a moonless night?


The short answer is that it's equivalent to the white zone. The longer answer is that it's quite different, because the Moon's glow is distributed over the sky in a way fundamentally different from artificial skyglow. That results from the fact that artificial light wells up from the horizon, while moonlight shines down from above.

See my blog How Brightly Shines the Moon?

#3 gdd

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Posted 24 April 2013 - 10:51 PM

Hi Tony,

Thanks for the quick answer. That is quite bright.

Gale

#4 LivingNDixie

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Posted 27 April 2013 - 10:08 AM

I appreciate Tony's answer, but even if it is a Full Moon night, planets and double stars are still good targets if you want to get some scope time.

#5 Illinois

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Posted 28 April 2013 - 06:41 AM

I go to dark sky on my vacation during no moon. I wondered, if the sky is gray zone and you mean that the full moon at night in gray zone turn to white zone?

#6 nytecam

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Posted 28 April 2013 - 02:15 PM

Very useful report Tony. :bow: LP from my London backyard obsy is severe to the point that late dusk just freezes and gets no darker. But I've a workaround via my cam in brief exposures which are stacked to go deeper ONCE the bright sky background is removed. The moon makes little difference to my imaging except for a few days around full moon when the skies are more polluted. :o

#7 audioaficionado

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Posted 01 May 2013 - 02:07 PM

I live in a orange/red zone and during the full moon, I couldn't even see Cassiopeia. No comet hunting that night.

#8 George N

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Posted 08 May 2013 - 04:04 PM

I go to dark sky on my vacation during no moon. I wondered, if the sky is gray zone and you mean that the full moon at night in gray zone turn to white zone?


One full-moon night in September, from my camp in the central Adirondacks (often 21.7 SQM reading on a dark night), I was surprised to be able to faintly make out the Cygnus Milky Way.

#9 gdd

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Posted 09 May 2013 - 09:43 AM


Quote:
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I go to dark sky on my vacation during no moon. I wondered, if the sky is gray zone and you mean that the full moon at night in gray zone turn to white zone?


--------------------------------------------------------------------------------



One full-moon night in September, from my camp in the central Adirondacks (often 21.7 SQM reading on a dark night), I was surprised to be able to faintly make out the Cygnus Milky Way.



The full moon's position in the sky may make a difference.

Gale

#10 George N

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Posted 09 May 2013 - 10:26 AM



Quote:
--------------------------------------------------------------------------------

I go to dark sky on my vacation during no moon. I wondered, if the sky is gray zone and you mean that the full moon at night in gray zone turn to white zone?


--------------------------------------------------------------------------------



One full-moon night in September, from my camp in the central Adirondacks (often 21.7 SQM reading on a dark night), I was surprised to be able to faintly make out the Cygnus Milky Way.



The full moon's position in the sky may make a difference.

Gale


Yes in deed! With the observation I noted (September) the moon was just coming up, while the Milky Way was high overhead.

#11 Tony Flanders

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Posted 09 May 2013 - 11:25 AM

One full-moon night in September, from my camp in the central Adirondacks (often 21.7 SQM reading on a dark night), I was surprised to be able to faintly make out the Cygnus Milky Way.


That doesn't surprise me at all.

For what it's worth, I can see the Cygnus Star Cloud (just barely) from my current favorite observing spot in Arlington, Massachusetts, deep inside the white zone.

#12 GlennLeDrew

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Posted 09 May 2013 - 07:05 PM

I find the Cygnus Milky Way is at the visibility threshold when the sky is at about 18 MPSAS, in the deep blue of twilight. Sky color may have a bearing.

#13 Tony Flanders

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Posted 10 May 2013 - 04:15 AM

I find the Cygnus Milky Way is at the visibility threshold when the sky is at about 18 MPSAS, in the deep blue of twilight.


That precisely matches my experience in light-polluted skies. It's invisible from my local city park, SQM typically around 17.8. And visible from Arlington, SQM around 18.3.

#14 TCW

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Posted 25 November 2013 - 03:08 PM

I am new to this topic. Can you explain SQM and how it is measured?

#15 richard7

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Posted 25 November 2013 - 03:25 PM

I am new to this topic. Can you explain SQM and how it is measured?


This should do it.






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