Airglow aus Frankreich [Nacht vom 24. auf den 25. Juli 2026]

[Nicolas Rossetto]

Hallo zusammen!

Wir hatten eine wunderschöne Nacht mit Nachthimmelsleuchten in Frankreich, beobachtet von den nördlichen Jura-Bergen aus in Richtung Nord-nord-west, bevor Staub von den südlichen Waldbränden mit dem Sturm aufstieg:



Der Monduntergang verbesserte die Sichtbarkeit des Nachthimmelsleuchtens erheblich, wie die folgende Montage zeigt. Die Höhe des zunehmenden Mondes über dem Horizont entspricht der Sichtbarkeit des Nachthimmelsleuchtens zu diesem Zeitpunkt:



Und hier das dazugehörige Zeitraffervideo. Der Mond geht gegen 1:45 Uhr unter, also gegen Ende des ersten Drittels des Videos.
https://www.flickr.com/photos/gaukouphoto/55418529515

Der modifizierte Kamerasensor (mit einem MC-Clear-Filter) trug sicherlich dazu bei, das rote Nachthimmelsleuchten deutlich vom grünen zu unterscheiden.

Ich habe außerdem eine kurze Animation von mitten in der Nacht hinzugefügt. Sie entstand durch das Übereinanderlegen aller vier Bilder, wobei für jedes Pixel der Minimalwert verwendet wurde. Dadurch können wir die Sterne, die am weitesten vom Polarstern entfernt sind, „verschwinden lassen“ und die Dynamik des Phänomens als Ganzes sichtbar machen:


HD full version: https://www.flickr.com/photos/gaukoupho ... datetaken/
Viele Grüße aus dem Jura!
Nicolas R.

[Automatische Übersetzung aus dem Französischen ins Deutsche mithilfe eines Online-Tools]

[Carl Herzog]

Hi Nicolas,

interesting airglow movement direction. I have never seen this fanning effect before. I always record airglow looking north, because the other directions are too light polluted where I live (50.2°N, 8.3°E). And there the airglow typically shifts in one direction.

In the last weeks we had several nights in a row with strong airglow. But as the sun was only shortly more than 18° below the horizon and I was focussed on recording NLCs, the chances to record airglow were quite limited.

Here is an example from 10 nights ago, where I recorded one hour in the beginning of the astronomical dawn. The images are heavily processed in order to equalize/remove light pollution as best as possible:

https://www.carl-herzog.de/akm/2026-07- ... irglow.mp4

White balance was set to 4750 K. Saturation and contrast boosts exagerate the color saturation.

Cheers

Carl

[JohannesZ]

Congratulations, Nicolas!
https://spaceweather.com/archive.php?vi ... &year=2026

[Nicolas Rossetto]

Hi Nicolas,

interesting airglow movement direction. I have never seen this fanning effect before. I always record airglow looking north, because the other directions are too light polluted where I live (50.2°N, 8.3°E). And there the airglow typically shifts in one direction.

Hello Cark, thank you for your message.

There too, when looking at north, which is also where I take Airglow most of the time for the same reasons as you do, I usually so green band moving from west to east, for the main one.
But sometimes, there is also other layers of air giving airglow, and you can see different airglow pattern, a bit like we can see different pattern of clouds, giving the different layers in the troposphere (correct me if I am wrong).

If anyone wants to take a closer look, I put there my original videos I made, with high bitrate in order to not be limited by Flickr video compression

By the way, inside the main pattern, I noticed at least two others:
- at the beginning of the time-lapse, between the 13rd and the 19th second (on 2026-07-24au25-[23h01à05h00]-NNW-14mm-MCC-Astro+AG-15''-ISO1600-36Mbps-24fps.avi), we can slightly see a thing dark band coming from the horizon towards the camera, which can be (I suppose) associated with another layer of air up there producing airglow.
This dark band is a bit more visible on the red channel time lapse video (between 00:02 and 00:05), with image processing using the minimum of 4 images for each pixel, in order to get rid of most of the stars: 2026-07-24au25-[23h01à05h00]-NNW-14mm-MCC-Astro+AG-15''-ISO1600-Min-[8-4]-R-bw-24fps.avi)
- after the moon set, when contrast is at its best, we cam see patches of different gravity waves patterns, compare to the main one, here and there adding undulations on the ones already there. I wonder if this can be on the same layers of air or if this is above or under.

Here is an example from 10 nights ago, where I recorded one hour in the beginning of the astronomical dawn. The images are heavily processed in order to equalize/remove light pollution as best as possible:https://www.carl-herzog.de/akm/2026-07- ... irglow.mp4

Did your camera have a standard filter, like the ones on digital cameras ? Or is this filter-modified (MC-Clear filter, ...)
It looks like the bands you caught that night are similar to the ones I got.
I cannot compare to pictures I might have taken, since we were under storms that night.

Congratulations, Nicolas!
https://spaceweather.com/archive.php?vi ... &year=2026

Thank you,Johannes !

Cheers.
Nicolas

[Carl Herzog]

Hi Nicolas,

the link you provided apparently requires an OK from you to be accessed. In case you get an inquiry from just a few minutes ago, it's from me

The airglow I typically see makes the impression that it is constituted of two layers: a green layer covering the full sky, and a red (and sometimes violet) layer moving in bands over the green layer. Not sure if this is what is really happening, but this is what my brain perceives when I look into the camera display and also in the time lapses.

Although I have full spectrum cameras for astronomy, for airglow I use my normal Nikon camera with its factory filter. The main reason is that it is difficult to use the full spectrum cameras with a clear filter on very fast wide angle lenses. The vignetting is stronger and the corners show severe star defects that are not present on a normal camera. So I would have to shoot at F4 or so, which is is simply too dark for airglow. But in a second thought, as airglow doesn't require perfect image quality, I will by chance do a test wide open with an astro camera to check if there is some more red in the images.

The median filter you applied on multiple images per frame is visible in your video: only the region very near to Polaris shows stars for this reason. I typically also use this technique for airglow (sometimes I even use Starnet to get rid of the stars, which clearly is more time consuming), but for the above video I decided to use only 3 images per frame to keep most of the stars in the video, as the airglow was strong enough to dominate the imagery.

I definitelly need vacations on a very dark site for these kind of things.

Cheers

Carl

[Nicolas Rossetto]

Hi Nicolas,

the link you provided apparently requires an OK from you to be accessed. In case you get an inquiry from just a few minutes ago, it's from me

Done.
And I re-set in order that anyone could see the files now.

Although I have full spectrum cameras for astronomy, for airglow I use my normal Nikon camera with its factory filter. The main reason is that it is difficult to use the full spectrum cameras with a clear filter on very fast wide angle lenses. The vignetting is stronger and the corners show severe star defects that are not present on a normal camera. So I would have to shoot at F4 or so, which is is simply too dark for airglow. But in a second thought, as airglow doesn't require perfect image quality, I will by chance do a test wide open with an astro camera to check if there is some more red in the images.

When I got the camera with a clear filter, the first thing I tried was to use two cameras side by side on a roof window, with the same settings, lens and same processing for images and this is was I discovered: red bands (with the good white balance set) with the clear filtered camera and nothing on the canon factory filtered camera (both EOS 6D): There is the time lapse corresponding https://www.flickr.com/photos/gaukoupho ... datetaken/

The median filter you applied on multiple images per frame is visible in your video: only the region very near to Polaris shows stars for this reason. I typically also use this technique for airglow (sometimes I even use Starnet to get rid of the stars, which clearly is more time consuming), but for the above video I decided to use only 3 images per frame to keep most of the stars in the video, as the airglow was strong enough to dominate the imagery.

I didnot know Starnet, I will try it, thank you.

Nicolas

[Carl Herzog]

Hi Nicolas,

thank you. Now a lot more things are visible!

I am trying to figure out what the yellow color means in the video. Did you use a real clear filter (with no filter effect at all) or an IR/UV-filter for the full-spectrum camera?

Regards

Carl

[Nicolas Rossetto]

This was a real clear filter (MC-Clear from Astronomik)
But the white balance is maybe not the best one for night landscape.

I provided one raw file on the shared folder , at the apex of the phenomenon, if you want to try other color temperature and green gain.
Regards
Nicolas

[Carl Herzog]

Hi Nicolas,

with a clear filter on a full spectrum camera it's impossible to get a natural white balance, as the camera is seeing things our eyes cannot see. So we are in false color territory anyways. I tried different settings in Lightroom with your image, but none gives a clean combination of green and red airglow. But I think you are already very near to the white balance settings I would use for my full spectrum Nikon camera (a modified Z5) in order to get as near as possible to a close-to-natural looking night sky result. This for sure only works well when there is no (or only few) IR and UV in the sky.

Normally I would guess that the yellow color in the images comes from light polluted low altitude clouds or aerosols. But according to https://www.meteoros.de/themen/atmos/se ... nd/airglow there can also be yellow airglow at 92 km height coming from sodium bicarbonate. Now, if the yellow part is only visible in the full-spectrum camera, I would guess its not comming from the sodium bicarbonate, but rather due to IR wavelengths coming from the 86 - 87 km height and produced by emissions from the hydroxyl radicals. When IR and green are combined, we probably also get yellow in the full spectrum camera.

I guess I'll have to give the full spectrum airglow recording a run.

Regards

Carl