Starship Asterisk*

APOD received this image from Dave Willis on behalf of Kris Byrd; it was taken the morning of December 31 in West Virginia. He writes, "If you can help us understand the halo around the tree and the spot of color next to the bush we would appreciate it."

I notice there are other similar spots elsewhere in the picture; I can't explain any of them and hope someone else can. Thanks!

[attachment=0]photo-2.jpg[/attachment]

It's beyond me. But would appear to be a kind of sun-dog effect, the sun reflecting off clumps of ice crystals, that are formed in a narrow swath.
Did he say how long it was observeable?

The halo was visible with the naked eye; the temperature was probably in the mid to upper 20s. The photographer was inside when she noticed the halo around the tree, so went outside onto the deck to take pictures of it. She did not notice the light by the foreground bush until she looked at the pictures, as she was so taken with the light encircling the tree. I don't know the duration of the halo, except that she says the halo was visible as long as the sky was pink.

I have three other pictures, all taken within about a minute or so of one another on an iPhone. I reduced this image slightly to post it here; I have not reduced the others and await permission to post links to them.

I'm wondering if the backside of the tree with the circle is lit-up? It seems to be in a straight line towards the neighbors, with just a little showing under the left side of the big tree just to the right and behind the circled one. It is a bit strange that all the reflections seem to have targeted trees. But hey, it's a strange world

owlice wrote:The halo was visible with the naked eye; the temperature was probably in the mid to upper 20s. The photographer was inside when she noticed the halo around the tree, so went outside onto the deck to take pictures of it. She did not notice the light by the foreground bush until she looked at the pictures, as she was so taken with the light encircling the tree. I don't know the duration of the halo, except that she says the halo was visible as long as the sky was pink.

I have three other pictures, all taken within about a minute or so of one another on an iPhone. I reduced this image slightly to post it here; I have not reduced the others and await permission to post links to them.

It isn't uncommon to have different kinds of snow around a tree- underneath, it is affected by tree litter and snow dropping from branches. Around the edge, the snow drops a little differently from branches, and sometimes drifts just a little. Snow under the tree, in a halo around it, and in the wider fields is all exposed to the Sun differently, and therefore can end up with different surface textures, as well.

I wish the photographer had examined and reported on the snow quality. My guess is that there is a ring of snow around the tree that has melted and refrozen, forming an icy veneer that is reflecting the sky, while the snow out in the open is just a little bit rougher, and therefore less specular.

Chris Peterson wrote:

owlice wrote:
The halo was visible with the naked eye; the temperature was probably in the mid to upper 20s.

It isn't uncommon to have different kinds of snow around a tree- underneath, it is affected by tree litter and snow dropping from branches. Around the edge, the snow drops a little differently from branches, and sometimes drifts just a little. Snow under the tree, in a halo around it, and in the wider fields is all exposed to the Sun differently, and therefore can end up with different surface textures, as well.

I wish the photographer had examined and reported on the snow quality. My guess is that there is a ring of snow around the tree that has melted and refrozen, forming an icy veneer that is reflecting the sky, while the snow out in the open is just a little bit rougher, and therefore less specular.

Note that the early morning temperature was just below freezing.

Probably overnight air temperatures were above freezing even though a clear sky/calm wind temperature inversion kept the ground at below freezing temps.

Overnight snow melt off the tree thus refroze into an ice ring that reflected the sunrise.

SNOW MIRRORS. Who wudda thought? But it does explain why it shows under trees, except perhaps for that little tree in front, where the colored spot is off to the side. Maybe there's a slight depression in the ground there that acts like a round mirror?

More pics and info:

Original posted photo
Additional photo #1
Additional photo #2
Additional photo #3

The photographer writes:

I would say the halo & sunrise lasted at least 10 minutes, maybe 15. I first noticed this when it was still fairly dark. In other words, the halo showed up early in the sunrise and remained strong in appearance until the colors in the sky went to blue.

What struck me when I saw it first was that the halo was complete. I wondered why there wasn't a shadow caused from the east. It was remarkable to say the least.

Chris and Neufer, thanks for your comments! Snow melting, refreezing, and then reflecting the sky makes sense. Probably.

With the additional photos, you can see the reflected sky a little bit around the bird house pole and another pole also, where the snow is at a slightly different angle and reflecting the sky. And also a sort of longer strip on the ground. With all the colorful winter sunrises I've seen, I've never seen the snow reflecting the sky before.

I live with Kris and am very curious about the photo. More about the snow: It had been in place for more than a week and had a solid icy crust. Most likely there was a slight mound around the tree from snow falling off. In addition the wind had blown steadily for at least two days so the entire snow field had (still has) a wavy quality. Kris was roughly 15 feet above and 60 feet away from the base of the tree.