Page 1 of 1

APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 5:05 am
by APOD Robot
Image Sun Halo over Sweden

Explanation: What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals. As these crystals flutter to the ground, much time is spent with their faces flat and parallel to the ground. An observer may find themselves in the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our view and creating phenomena like parhelia, the technical term for sundogs. The featured video was taken in late 2017 on the side of a ski hill at the Vemdalen Ski Resort in central Sweden. Visible in the center is the most direct image of the Sun, while two bright sundogs glow prominently from both the left and the right. Also visible is the bright 22 degree halo -- as well as the rarer and much fainter 46 degree halo -- also created by sunlight refracting through atmospheric ice crystals.

<< Previous APOD This Day in APOD Next APOD >>

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 4:43 pm
by orin stepanek
Twas hoping to find a photo of today's video; but no luck! :?
52410bb8e691b267f97d9278_736.jpg
Pretty kitty ts a good observer though!

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 7:31 pm
by neufer

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 8:30 pm
by alter-ego
The cat reminds me of Clark Griswold daydreaming about his future pool, among other things... :D
 
Clark Griswold at Window.jpg

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 9:45 pm
by Fred the Cat
Good thing these skiers don’t live in a world where water freezes into
lens-shaped
crystals.

These folks would be toast. :oops:

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 9:54 pm
by johnnydeep
So, if the two bright spots on either side are sun dogs, what is the bright fountain-looking thing on top?

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Tue Dec 28, 2021 10:27 pm
by alter-ego
johnnydeep wrote: Tue Dec 28, 2021 9:54 pm So, if the two bright spots on either side are sun dogs, what is the bright fountain-looking thing on top?
Upper tangent arc
Atmospheric Optics
Tangent Arcs

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Wed Dec 29, 2021 3:37 pm
by rj rl
johnnydeep wrote: Tue Dec 28, 2021 9:54 pm So, if the two bright spots on either side are sun dogs, what is the bright fountain-looking thing on top?
check out this Cloud Of The Month if you wanna know the names of some of the more rare optical effects:
https://cloudappreciationsociety.org/december-2021/

Re: APOD: Sun Halo over Sweden (2021 Dec 28)

Posted: Wed Dec 29, 2021 4:16 pm
by johnnydeep
alter-ego wrote: Tue Dec 28, 2021 10:27 pm
johnnydeep wrote: Tue Dec 28, 2021 9:54 pm So, if the two bright spots on either side are sun dogs, what is the bright fountain-looking thing on top?
Upper tangent arc
Atmospheric Optics
Tangent Arcs
rj rl wrote: Wed Dec 29, 2021 3:37 pm
johnnydeep wrote: Tue Dec 28, 2021 9:54 pm So, if the two bright spots on either side are sun dogs, what is the bright fountain-looking thing on top?
check out this Cloud Of The Month if you wanna know the names of some of the more rare optical effects:
https://cloudappreciationsociety.org/december-2021/
Thanks!