An interesting ray phenomenon (Mystery!)

[geckzilla]

Clicking the above image will take you to the Flickr page where there is some information supplied about the photo. If Flickr gives you trouble, here is a direct link to the full size image.

Some basic, condensed info:
Looking south, around midnight 2014 July 4. A half phase moon was setting or perhaps had already set. Coordinates of photographer's position are 47.6594130, 6.8128810

Hi Judy, thanks a lot for looking into it! I've been wondering what it was for months, and could not really find people who could help as much as you!
So, to reply, here are some more details.
The time was about midnight so the sun was gone way before that and I was with a friend on top of a small mount called "le Salbert" ( http://fr.wikipedia.org/wiki/Le_Salbert ), 650m high.
Here's the exact sport where we were : http://goo.gl/maps/rKocs
As you guessed I was facing South, and I'll let you zoom out in Google Maps to see the surroundings (a relatively small city right before me, and mostly countryside behind with the Vosges mountains way behind).
The lights lasted several minutes if I recall correctly, I'd say from 5 to 10 mins. The beams were not moving but their intensity was varying. Then they started fading out and never reappeared. I went there by night again several times in the past months after this event, but nothing like that ever happened again.
I got really lucky that time because I was just doing test shots for my star trails shots, and my friend was already in the middle of a long Bulb exposure so he couldn't capture the phenomenon.

I've looked up "anticrepuscular rays" and it looks like it can't happen by night, but I saw this thing at around midnight so it probably wasn't that.

Sorry for my imperfect english and lack of technical knowledge but I'm really glad you're helping me out with this. I'm really curious to find out an explanation !

Have to say I've not encountered this phenomenon before. Has anyone else seen anything similar or have any ideas? My only idea is a very general one: A bright light somewhere from the north behind some object which illuminates small sections of the sky, creating rays similar to anticrepuscular rays. I am stumped beyond that.

[Chris Peterson]

Have to say I've not encountered this phenomenon before. Has anyone else seen anything similar or have any ideas? My only idea is a very general one: A bright light somewhere from the north behind some object which illuminates small sections of the sky, creating rays similar to anticrepuscular rays. I am stumped beyond that.

It was still astronomical twilight, with the Sun just 17° below the northern horizon. But I think that's too low to produce anticrepuscular rays, and in any case the convergence point here appears lower than 17° altitude, which would be the antisolar point (give or take a bit for refractive effects).

I'd suggest we aren't seeing rays that originate from a light source behind us, but rather in front... perhaps from Bern or one of the other larger cities which lie less than 100 km to the south. The amount of light isn't all that great... the rays appear to be similar in brightness to the Milky Way.

The color is interesting. Switzerland has been converting a lot of its street lighting to LED, though, which could be what we're seeing.

[geckzilla]

True, I should have considered a front source more seriously. It looked like the rays were ending rather than starting there but the shape of rays is the same whether looking at the source or the other side.