Observe a partial solar eclipse – Astronomy Now

The partial phase of the August 21, 2017 total solar eclipse, the so-called ‘Great American Eclipse’. Pictured: Jamie Cooper.

This month’s partial solar eclipse is visible across the length and breadth of the UK on the morning of October 25, 2022. Solar eclipses visible from the UK are quite rare, so this event provides a nice opportunity to watch the Moon gradually encroach on the Sun.

The partial eclipse begins shortly after 10am BST, when the Moon makes contact with the northern limb of the Sun. Observers in Scotland are slightly in the front line, at 10:03 BST, and they will see 30.6% of the diameter of the larger hidden Sun (see table below).

AT NO POINT during this eclipse should you look directly at the Sun, as you can during an entire total solar eclipse when the entire Sun is covered by the Moon. The best way to see is by “projection”, when a pair of binoculars or a small telescope can be used to project the solar disk onto a white map; you need to cover the main optics of the instrument, as well as any viewfinders while aligning the Sun (see image).

Projecting the solar disk through a small telescope onto a sheet of white cardboard is a safe method of viewing the partial eclipse. Photo: Steve Ringwood.

The eclipse is visible across most of Europe, where cities further east, such as Berlin and Warsaw, will experience a larger partial eclipse (magnitude of 43.6% and 52.1%, respectively). Chelyabinsk, in the Urals Federal District of Russia, has the distinction of the greatest eclipse for a major city; at 2:02 p.m. local time, 83.4% of the solar disk will be hidden by the Moon (the maximum eclipse occurs at 11:01 a.m. UT, with a magnitude of 86.19%, or 0.8619).

The “magnitude of the eclipse” is the fraction of the diameter of the solar disk covered by the Moon (it can be expressed as a percentage or as a decimal fraction [i.e. 30.6% or 0.306]. Eclipse obscuration is the fraction of sunlight Region obscured by the moon.

On the morning of October 25, there is an excellent opportunity to see a partial solar eclipse. At maximum eclipse, 30.6% and 25.9% of the Sun’s diameter is obscured by the Moon of Edinburgh and London at 10:55 and 10:59 BST, respectively. A whole graphic by Greg Smye-Rumsby.

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