29 replies to this topic

[mountain monk]

I concur with the above. According to DaveL's map my best observing site is 21.98 and all of them are above 21.9. I did see those numbers years ago with my SQM-L but not recently. My last observing trip up there recorded 21.89. Things may not be that bad, but I've been observing a lot less the past year due to wildfire smoke.

 

Dark, clear, calm skies.

 

Jack

[triplemon]

Yeah, "clear" skies also got a new spin added the last few years. One that is unlikely to abate over the next five and a half years, sigh.

 

So far, we're in luck here. First major star parties for the year the next two weekends. All of them were moved up from their historic July/August dates.
 

https://atmosphere.c...me=202506120300

Edited by triplemon, 12 June 2025 - 09:21 PM.

[Redbetter]

Still bright nights in general, although a few have nudged closer to period norms (still to the bright side.)  Haven't seen anything truly dark with clear sky in years though.  I might venture out to one of my more remote sites for a few nights next week if fires don't pop up and weather looks favorable.

 

A 21.8 would be marvelous anymore.  I get excited about 21.5 now or anything approaching it.  I fear that growing lighting glow was only augmented by the solar maximum, and that the step shift will remain even after natural airglow has subsided.  Such is the nature of annually increasing lighting menace.

[AstroFam]

Here's an interesting data point on this topic. I have SQM readings taken one year apart at Starry Meadows, a property owned by the Colorado Springs Astronomical Society. It's a very rural setting, with almost no close neighbors to cause variations in light levels.

 

Below are the SQM readings I took last year and recorded in my observing journal. I have the wide-angle model SQM.

 

06/04/24 - 21.4

06/05/24 - 21.3

06/06/24 - 21.3

06/07/24 - 21.3

 

I was quite pleased to see better numbers this year.

 

06/19/25 - 21.64

 

I know in years past even better SQM numbers have been observed, so I'm eager to see if they improve further in the future.

[George N]

Add one more who has seen a couple tenths change in SQM-L readings at my dark site (21.9s now read 21.8s, sometimes 21.7s).

But as to whether I don’t observe DSOs due to this, heck no. I still observe.

......

This provides a very good extra argument to offer to your spouse to justify getting a bigger telescope! 18-inch Dob anyone? Just use all that aperture to bore thru those brighter skies! 

 

The early 'dark nebula' astronomer EE Barnard was probably the first to publish a paper about his so-called "night glows" and their impact on his wide-field astrophotography. ...and this was the late 19th Century! He brought up the subject often (one similar reference https://adsabs.harva...SidM....5..129B). I'm not sure what the astronomers of the time made of it - but almost certainly he was observing dim aurora or noctilucent clouds.

 

Somewhere on my HD I have copies of a few published papers of Barnard on the subject of "night glows" - but I can't find them right now. It might be a good topic to research on a "cloudy night".  

 

I also remember the topic being mentioned in typical amateur astronomy books of the 1950's and 60's -- back when Light Pollution was far less of an issue for most amateurs - but "night glows" were.

Edited by George N, 27 June 2025 - 11:22 AM.