Double Sun Illusion

Fred Klein · Post by **Fred Klein** » Thu Jan 12, 2006 12:13 pm

It was a bright clear winter day when I happened to look up at the sun while stopped at a traffic light. I was amazed to see TWO perfectly identical suns - one above the other - distinctly separated. Both were surrounded by a streaky band of clouds. The illusion lasted for about 5 minutes; then both images became obscurred. The brightness of the sun(s) was sufficiently diffused by the clouds to permit direct viewing without discomfort.

Now, I'm guessing it was an unusual ice crystal refractive phenomenonon; however I've never heard it mentioned in the literature. Perhaps one of you can explain this phenomena or point me to a reference/pictures.

S. Bilderback · Post by **S. Bilderback** » Thu Jan 12, 2006 12:39 pm

A little more information would help. What time of day, where was the Sun in relation to the horizon, the estimated temperature, are there any mountains, valleys, bodies of water?

Did this involve any alcohol or controlled substances? Just kidding!

orin stepanek · Post by **orin stepanek** » Thu Jan 12, 2006 1:19 pm

I have seen this anomaly a time or two. Maybe some literature can be found on the subject.
Orin

gordhaddow · Post by **gordhaddow** » Thu Jan 12, 2006 3:19 pm

In all probability, the actual position of the sun would have been directly behind the thickest part of the cloud, and the images you saw were 'sun dogs' created in the thinner fringes. These bright spots are created at 22-1/2* from the sun's position (in any direction), usually in high ice clouds. Beautiful things to see, given a rather strict set of conditions that have to come together by random chance.

Fred Klein · Post by **Fred Klein** » Thu Jan 12, 2006 4:56 pm

Specifics...

I'm guessing it was about 2PM, quite cold - in the 20-30F range. The location was over land - however, Long Island Sound is about 2 miles away. No controlled substances

S. Bilderback · Post by **S. Bilderback** » Thu Jan 12, 2006 10:32 pm

I'm guessing it was about 2PM, quite cold - in the 20-30F range.

Quite cold? Where I come from we a looking for our tee shirts at 20* F

For ice crystals to form in the amount need, I would guess that some much colder air was trapped above 3000 ft line. The wetter, warmer air must have been mixing with the colder air in a relatively thin layer producing the reflective ice crystals making the Sun Dog from your vantage point near the same size as the Sun. I would have liked to see that.

makc · Post by **makc** » Fri Jan 13, 2006 7:28 am

yo, check dis out, nigs 8)