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Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sat Sep 25, 2021 9:25 am
by realflow100
I can see magnitude 4.8 stars no problem. almost with direct vision. Not a whole lot of difference between averted and direct vision.
magnitude 5 is very hard though and needs averted vision to see. but I saw one a couple times for a split second enough for me to recognize it and match it to a star on stellarium.
My bortle level is normally a high bortle 7 or low bortle 8.
I even glanced andromeda in far averted vision a couple times. but it was extremely difficult. even finding the star next to andromeda is quite tricky.

earlier this night I even was able to make out a very vague faint band of where the milkyway is near the zenith when cassiopeia was getting sorta high in the sky. but only in far averted vision. and its just a featureless cloud-like hazy band going across the sky. I confirmed by checking in stellarium and that matches where I saw the milkyway.

I also counted up to 8 stars in pleiades even with it being so close to the moon.

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sat Sep 25, 2021 10:44 am
by pakarinen
B7-8, but typically mag 3.5. Several variables involved.

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sat Sep 25, 2021 1:11 pm
by helicon
Around magnitude 4.5-5 on an average night, 5.5 on an excellent night. With the moon almost full, perhaps 3.

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sat Sep 25, 2021 1:24 pm
by GCoyote
About 3.5 - 3.7 on average.
I think the air pollution and having sprawling suburbs in all directions makes it worse.

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sat Sep 25, 2021 1:56 pm
by KingNothing13
No idea, but when I took the dog out at 11pm last night, the moon was shining fully, and I could see a few stars.

The ground was SOAKED From humidity and dew though, so I didn't bother to setup :lol:

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sun Sep 26, 2021 12:57 am
by realflow100
Dang
Are my results normal. below average. or above average? For what stars im able to see under the nearly full moon (From yesterday)? compared to you guys? I'm really curious!
being able to just barely glance magnitude 5 stars with a lot of effort and averted vision. and magnitude 4.8 stars quite readily. (still very difficult but can almost direct vision 4.8 stars)
as well as andromeda galaxy very very very faintly in VERY far averted vision. extremely difficult. and the milkyway somewhat near the zenith. very faintly. no details though. just a very faint glowy band.

my bortle level is normally 7-8 with no moon. and bad/average transparency

On the very best nights with extremely good perfect transparency and clear/no moon its more closer to bortle 6. andromeda almost a direct vision object. but still no orion nebula. I only see stars where orions sword is. looks like 3 pairs of stars.

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sun Sep 26, 2021 2:04 am
by OzEclipse
The Pleiades is a reasonably good object to do such a comparison with a variety of stars ranging from mag 2.8 to below naked eye. The visual magnitude limit near full moon has less to do with how dark your skies are and more to do with how polluted your skies are. In the cities, this is smog and smoke, in the country, dust, pollen, and smoke from crop chaff burn off or bushfire. If you want to do a comparison, doing it when the Moon is nearby isn't the best approach because at best, you are looking at pollution which varies with time but also people seeing the post and doing their estimates at different times, even just a few hours apart, will have the Moon positioned differently relative to the Pleiades or any other target. If you want to do something like this, make it full moon, make it at Moon transit and make the star magnitude test area a long distance from the Moon so that motion of the Moon against the stellar background has minimal effect.

Probably better to collate data from any Moonless night. Transparency will still play a part but less than when a near full Moon is up.

I have never estimated magnitude limit during a near full Moon so can't offer you any estimates.

The attached chart is on of my images with magnitudes extracted from Starry Night Pro mostly based on Tycho and Hipparchus catalogue magnitudes.
Pleiades-magnitudes.jpg

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sun Sep 26, 2021 2:09 am
by realflow100
if I count 8 to 9 stars in pleiades with no moon on the best perfect clearest night approximately what would that put me in? at the time I could also see andromeda almost with direct vision. in averted vision it was obvious

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Sun Sep 26, 2021 3:00 am
by OzEclipse
realflow100 wrote: Sun Sep 26, 2021 2:09 am if I count 8 to 9 stars in pleiades with no moon on the best perfect clearest night approximately what would that put me in? at the time I could also see andromeda almost with direct vision. in averted vision it was obvious
If you look at the chart below that I provided the 8th and 9th brightest stars are both about mag 5.4. Andromeda is about magnitude 3.5? Not a difficult naked eye object with the naked eye where the light is concentrated into a small area of the retina.

Joe

Re: Whats your naked eye limiting magnitude under the current 83% moon?

Posted: Mon Sep 27, 2021 2:57 pm
by Arctic
I can see stars to mag 5 on a full moon night with good transparency.