Archive- Odd radius halos

I've seen a few odd radius displays, though none were very spectacular. However, one during April 5th 2011 was good. It was a terrible thunderstorm in the morning and it pouring down rain and lightning was flashing everywhere. I decided not to take my camera, and you know what? It cleared up an around noon there was a 9° halo!! Oh well! But there were still odd radius halos when I was home, just not as good as before.

As you can see, there are very noticeable odd radius

halos

Same, but unsharp masked. The 9° and 18° halos are noticeable.

Odd radius halo displays usually have broad 22° halos, this is because of the combined 20,22,23, and 24 degree halos. The odd radius halos are usually very faint as well. A convex mirror is almost a must. To show how faint they can be, here are pictures from a display on June 1st 2011. Notice the 18° halo to the right of the street lamp.

I would not have seen this without a convex mirror!

Same but USM, possible 9° halo and 18° halo.

The first odd radius halo I saw was a  23 degree plate arc I observed in September 2010. It was quite faint and I was new to halos, so I didn't know if it was a Parry arc or a 23 degree plate arc. However, at the sun elevation at the time, the Parry arc would be touching the 22 degree halo, but this arc wasn't. It was about a degree away, making it 23 degrees from the sun.

Odd radius halos actually might not be rare. What is rare is for them to be strong enough to actually see. Pyramidal crystals are not rare, but they just do not occur in enough quantity very often. Sometimes there could be odd radius halos, that you can only see after stacking and unsharp masking images.

46° halo

The 46° is a large, rare halo. It is typically very faint and easily missed, and the 22° halo might not even be bright. It should always be searched for though, very carefully too. The image had to be heavily unsharp masked for it to be seen easily.

Faint 46° halo

Original image

Another sundog

I observed another sundog this afternoon. It was very faint, so the picture is edited quite a bit.

Sundog

Saw a sundog and 22 degree halo this evening.

Rare halo display in Fall

I observed a spectacular halo display the 12th of November. You can see this display on OpticsPOD, this post just has more pictures of the halos.

The halos observed were:

• 22 degree halo
• Sundog
• Circumzenith arc
• Upper tangent arc/circumscribed halo
• Parry arc
• Parhelic circle
• 120 degree parhelion
• Supralateral arc
• Infralateral arc
• 46 degree halo
• Lowitz arc
• Wegener arc

Displays like this will happen, as long as you keep looking for them!

Parhelic circle

Infralateral arc (look carefully!)

Upper tangent, Parry, and Lowitz arcs. This halo

was much brighter than appears in the image.

Wegener arc, the image has been unsharp masked

so the rare halo shows up more clearly.

Later in the day, a CZA and supralateral

arc appeared in the sky.