Expert: Paul Wagner - 10/24/2007

Question
Hello. I have a question about a star and anomalie I saw outside last night. I will try to describe it the best I can. I live in Southwestern Washington State and saw this star by looking east. I am at sea level where I live and would estimate the star to be seen at about a 30 degree angle above horizon. I noticed with the naked eye that this star had like a prism effect very brilliant and pulsing very quickly green, blue, red. All I have handy is binoculars so I grabbed them and could see the star cleary but the prism effect seemed to be next to it now in a creasent shape. I figure this effect has to light and moisture reflection but I am not sure. Have you ever seen anything like this? Also which star would be where I described. I hope all my rambeling made sense. Also this took place October 23 at 2:00am.. I tried to look tonight but the cloud cover is to heavy. Thanks Mark

Answer
Hi Mark

This is a classic description of the effect of the atmostphere on a star that is low on the horizon.  The star is  point source of light, and as the atmosphere bends the light, we see different parts of the visual spectrum, glittering and flashing different colors.  Any bright star on the horizon will do this, but it helps to have a lot of air currents.

The star was probably Sirius, one of the brightest stars in the sky!

Paul Wagner