Wildlife UK Forum - Discuss the UK countryside and wildlife

Sorry to ask such a basic question! I've always wondered why if stars are just other suns, why to they twinkle, because our sun doesn't? I'm sure there is an obvious answer, but I would really like to know!

[font=Courier][color=#FFA500]Stars twinkle because they are a very very long distance away and the amount of light arriving here is very very small. As it passes through our atmosphere this light gets distorted & interrupted. This causes the light to appear to be twinkling.

If you were outside the atmosphere then there would be no distortion and the stars do not twinkle. (Ask an astronaut)

Any weak light source at night on earth can also appear to twinkle. If you've watched city lights from long distances away, perhaps on a plane at night, the weaker lights do appear to twinkle also for the same reason.

As for the sun, no amount of atmosphere can cause a visible twinkling effect because it is obviously much too bright to be effected.

Dave's exactly right. It's the atmosphere that causes the distortion, but the stars don't actually twinkle really.

HI All,
As already mentioned turbulance in the atmosphere causes the stars light to be scattered and distorted.Twinkling is most often noticable in frosty winter nights with rising air currents from the ground.Lower stars are worst effected as they shine through a thicker wedge of the Earths atmosphere, usually the bright stars overhead twinkle much less.Because stars are so far away they appear as pinpoints making them suseptable to twinkling,however the planets which although at first glance appear starlike are in fact tiny discs(often resolvable even with binoculars)and most often shine with a steady light even when all the true stars around them are twinkling like mad!From British latitudes the most famous 'twinkler' is the winter star Sirius it appears as the brightest star in the entire sky it doesnt rise far above the southern horizon from here so it not only twinkles but appears to flicker violently through blues,reds white and even greens ,a marvalous sight on a frosty winters evening.
Regards Les

As everyone has said they don't really twinkle. Its the atmosphere that causes the scintillation. If you were in Space they would appear constant. Its also one way of distinguishing between a star and a planet. Planets don't twinkle but appear as a constant bright light. In fact Jupiter is quite visible at night now in the south east.

I think I prefered it when I thought they did. First Santa Claus doesn't exist and now stars don't really twinkle. I don't think I can take much more.