Star trail

A star trail is a type of photograph that uses long exposure times to capture diurnal circles, the apparent motion of stars in the night sky due to Earth's rotation. A star-trail photograph shows individual stars as streaks across the image, with longer exposures yielding longer arcs. The term is used for similar photos captured elsewhere, such as on board the International Space Station and on Mars.^[2]^[3]

Typical shutter speeds for a star trail range from 15 minutes to several hours, requiring a "Bulb" setting on the camera to open the shutter for a period longer than usual. However, a more practiced technique is to blend a number of frames together to create the final star trail image.^[4]

Star trails have been used by professional astronomers to measure the quality of observing locations for major telescopes.

^ "All In A Spin". www.eso.org. Retrieved 1 August 2016.
^ Cite error: The named reference st-iss was invoked but never defined (see the help page).
^ Cite error: The named reference st-mars was invoked but never defined (see the help page).
^ Buckley, Drew (2015-04-22). "Star Trails: How to Take Captivating Night Sky Photos". Nature TTL. Retrieved 2019-07-14.

[1] "All In A Spin". www.eso.org. Retrieved 1 August 2016.

[st-iss-2] Cite error: The named reference st-iss was invoked but never defined (see the help page).

[st-mars-3] Cite error: The named reference st-mars was invoked but never defined (see the help page).

[4] Buckley, Drew (2015-04-22). "Star Trails: How to Take Captivating Night Sky Photos". Nature TTL. Retrieved 2019-07-14.

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