Adrian Dening's Stars Over Somerset

Wednesday, 27 July 2022 17:00

Monday 1st to Sunday 7th August 2022

Something a bit different this time. I often give a dire warning about the dangers of attempting to look at the Sun through binoculars or a telescope, but many astronomers do make successful observations of our neighbouring star in complete safety. How do they manage it?

The light you see originating from the Sun is classed as "white light" which is a mixture of all the different wavelengths or colours. A telescope for this is either fitted with a special filter in front that stops virtually all the light from entering the tube in the first place or a device called a Herschel wedge that bins most of the light collected by the telescope before it can reach the eyepiece. White light images are great for showing Sunspots - areas on the Sun's surface where the temperature is considerably lower than the rest of it..........4000 degrees Celsius as opposed to 5500 degrees!

A far more specialised type of telescope focuses on just the red wavelength of light given off by Hydrogen burning and these Hydrogen Alpha telescopes show stunning prominences or flares flying off the Sun's surface in real time. White light images are just too bright to show these prominences as the amount of light washes out the detail.

If you'd like to witness all this for yourself, I am running some "Daytime Astronomy" sessions with my Solar telescopes at Braeside House in Devizes during their Family Day on Saturday August 6th. Why not come along - entry is free and there are all sorts of crafts, activities and even a hog roast! To find the details, search for Braeside Education Centre on Facebook or the Interweb.