flashing star

[Ronnie67]

Hi guys, this might sound as though i am think, and at times I guess yo are all right, the reason being my unusual thicky queston. I have just this minute popped my head out of the door and noticed a star fickers vigarously, and changing colour, cannot pin point its location, pt i am sure if you loo out you can see it. just wanted to know what it is

[kevrees]

Is it close to the horizon (low down) and to the north? I just been outside with my binoculars for the past half hour or so (until a police helicopter started flying around totally obstructing my field of view) and saw the same thing. Im far from an expert and im sure someone with more knowledge will be along to clear this up soon enough but i think its a combination of the earths atmosphere and some other stuff that causes the flickering effect, not the actual star itself.

[Ronnie67]

To be quite honest kvrees I have no idea, not very clued up on the night sky, thats why i aked the question, i was hoping it to be a unique star, or something like that

[SteveA]

Thats the star Capella!..in the constellation of Auriga.

It's a bright star and being low down near the horizon, its light is passing through a thicker wedge of the atmosphere. Its the earth's atmosphere that leads to the familure "twinkling" of stars.

[DirkSteele]

"Twinkle, Twinkle little star, how I wonder what you are?"

"Well I am a big ball of mostly hydrogen and helium and my light is being refracted through your thick and turbluent atmosphere"

Stars are so distant from us that they behave as point sources. As the light they emit passes through Earth’s atmosphere, it is bent slightly whenever it passes through a region of slightly denser air. Different colors of light (though the stars appear generally appear white, their light is made up of a whole rainbow of colours), take slightly different paths, since the degree of refraction (bending) that light undergoes is frequency dependent. As the air in the atmosphere is turbluent and hence constantly moving, the light is continually passing through changing pockets of density and this results in the twinkling we see.

[Qualia]

Great answers.

Just as an aside, I use the twinkle of the sparklers to estimate how good will be my seeing for the evening. If the stars twinkle, it's not a great sign.

[Darkstar_1]

Star twinkling is actually called scintillation

[jimmyjamjoejoe]

Great answers.

Just as an aside, I use the twinkle of the sparklers to estimate how good will be my seeing for the evening. If the stars twinkle, it's not a great sign.

I do this too. I generally pick one at about 30-45 degrees and check for twinkling before getting the scope out.

That said, it was on a night of bad seeing that i got a 10 minute window of absolute perfection (the first and only time i've experienced seeing that good), so you never know...

[K3ny0n]

Kevrees - Are you by any chance near the Middlesborough area?

Funny how the police helicopter was out at exactly the same time. (not that there is only one helicopter in England )

Rob

[Ronnie67]

Thanks everyone for your help

[brantuk]

Check out the "Blinking Star" nebula for a very interesting optical illusion - use Stellarium to find it. It's not the star you were looking at - you'll need a scope - but it fascinating to watch - should be up twoards the autumn equinox.