EvC Forum: Why do stars sparkle?

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Topic: Why do stars sparkle?

Greengreen

Junior Member (Idle past 4593 days)

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Joined: 09-30-2011

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Message 1 of 3 (635623)
09-30-2011 7:41 AM

Looking at the 'picture of the month', you can see horizontal and vertical lines emanating from the stars - the familiar 'sparkle'. As this effect is created both in photographs and by eye, (from any light source, not just stars) I'm guessing it has something to do with the lens, and refraction? Does anyone have a thorough explanation for this simple phenomenon?

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	Message 3 by cavediver, posted 09-30-2011 8:41 AM		Greengreen has not replied

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Message 2 of 3 (635626)
09-30-2011 7:50 AM

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cavediver

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Message 3 of 3 (635630)
09-30-2011 8:41 AM

Reply to: Message 1 by Greengreen
09-30-2011 7:41 AM

Looking at the 'picture of the month', you can see horizontal and vertical lines emanating from the stars - the familiar 'sparkle'.

No, that's not a "sparkle" or "twinkle". Twinkling is atmospheric distortion caused by varying densities of convection currents in Earth's atmosphere.

The crosses are diffraction spikes caused by the cross struts (or spider) in the telescope that support the secondary mirror.

Edited by cavediver, : No reason given.

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