A diffuse bright V-shaped light in the sky, slightly redder on the lower edge, with a faint arc of light extending downward from the center.

When I first started paying attention to solar ice halos, I read about tangent arcs. But this is the first time I’m sure I’ve seen one. The tangent arcs appear above and below the sun, branching out from the 22° circular halo (which you can see here, very faintly), and change shape depending on how high the sun is in the sky.

It was late afternoon, and the sun was behind the next building over. I ended up snapping a shot with my phone, wishing I could have grabbed a better camera, but the Pixel 2 caught a surprising amount of detail once I adjusted the brightness to bring it out. (No, the sky wasn’t this dark!). It’s a far cry from the G1’s photo of a very blue (and blurry) set of halos 10 years ago, or even the Galaxy S4’s colorless rainbows at sunset four years ago.

A small cloud shows a spectrum, cut by a contrail that also cuts through part of a circular halo.

I noticed the halo around the sun as soon as I walked out the door for lunch on Thursday. The rainbow cloud? That appeared as I walked past a building. I saw it as soon as the southern sky came into view again.

The colors got more intense over the next few minutes, and I kept taking photos until my phone locked up. I stood there watching the colors intensify, then fade, while I pulled out the battery and waited for the phone to reboot.

A man who’d been sitting nearby, buried in his phone, looked up wondering what I was taking pictures of. He’d never seen anything like it before, and wondered what it was, and fortunately I was able to answer.

At the right angle, ice crystals in a cirrus cloud refract sunlight to produce a feathery rainbow effect. The circumhorizon arc runs parallel to the horizon, and while it can be long, it’s usually only seen in fragments like this. I’ve only seen a few of these myself, and it’s been years since I’ve seen one this intense. I took this photo through my polarized sunglasses, but the colors were bright even without them.

When my phone froze, he offered to send me one of his pictures just in case mine hadn’t actually saved. Fortunately they had, and I actually posted to Flickr several hours before his message made it through the cell network.

Within a few minutes, the cloud had drifted out of alignment, and the colors had faded completely.

An hour later, on the way back from lunch, I noticed a longer patch in a smoother cloud layer, but it was faint enough that I could only barely see it with my sunglasses on. Without them, it faded completely into the glare.

If I’d had my better camera with the zoom lens, I would have gotten some better shots of just the bright cloud. Then again, I wouldn’t have been carrying it with me to lunch, and the effect was gone in the time it would have taken to run back in and get it. So it’s probably just as well I stayed and watched instead.

Funny thing: I posted a cropped view on on Instagram featuring just the arc fragment and contrail. When I went back to look at the #rainbowcloud tag last night, I found no less than SIX other photos of what was clearly the same cloud at various points in its five-minute lifetime!

You may never seen a halo around the sun or a sundog next to it, but they’re actually quite common. You just have to look up. (Just don’t stare at the sun!) I usually keep an eye out for sun halos whenever there’s a thin cloud layer, since there usually aren’t ice crystals near the ground in LA, but the upper atmosphere is a lot colder.

I actually wasn’t looking for this halo. I just happened to look up toward the tree across the street and *wham* – there it was.

Just one day later, I saw a fainter halo while walking to lunch…and noticed this rainbow-like sundog off to the right of the sun. I tried to take another shot with my sunglass lens in front of the phone, but fumbled it, and by the time I fixed the settings, it was gone.

You don’t even have to be outside — a few weeks ago I posted a view through an office window. But you do have to look up once in a while!

Sun Halo Behind a Plant FrameI spotted this great halo yesterday while we were out shopping for plants for a vegetable garden. The bright, colorful upper arc just jumped out, and while I searched for something I could use to block the sun for a photo, I also shaded my son’s eyes with my hand so he could look too.

It was still visible 20 minutes later and a few miles away, when I noticed that the upper arc looked like it split to the left, probably a circular 22° halo with a circumscribed halo around it. That would touch the circle at the top, where it’s brightest, then branch off on tangents to the sides — and it does look like that may be going on even in this shot, on both sides, though I didn’t notice it at the time. Halos like this are caused by reflections in ice crystals, but the ice can be in the upper atmosphere. It was plenty warm down here on the ground, around 80°F.

We did make it out to Mysterious Galaxy for California Bookstore Day (though they only had a few of the exclusives left by the time we arrived — apparently there was a massive rush that morning), but ended up missing Free Comic Book Day. It became clear while we were out running around that J wasn’t going to stand for waiting in line in the heat, and I never quite managed to get back out there myself after the rest of our errands were done. It didn’t really seem that urgent, two weeks after WonderCon (I still need to write that up, but you can check out my convention photos now).