Amazing Almaaz

andy · #1 20-02-2007, 03:59 PM

.
.
.when observing Saturn last Sat 17th a friend pointed out a star that seemed to be flashing different colours, no, not just twinkling.

I checked to see what it was with my new Celestron Skyscout (a great boon to beginners like me) and it identified it as Almaaz, which it tells me is 172 x the size of our Sun.
My question is why did it seem to be flashing and changing colours? blue and red were the most obvious.

[1ponders] (Paul) · #2 20-02-2007, 04:04 PM

About what time was it Andy? ie how high above the horizon was it?

Chrissyo (Chris) · #3 20-02-2007, 04:04 PM

How high up was the star? When low in the sky many stars do this. This is because the lower the star is in the sky, the more atmophere you are looking through. With more atmosphere in the way, there is a greater chance for the starlight to be refracted by shifting air which makes it appear to change colours.

andy · #4 20-02-2007, 04:12 PM

Yes, it was fairly low, about 15 degrees above my horizon. it was about 9.30pm ( of course it was PM!)