Alan Willison, chairman of Hertford Astronomy Group, offers his tips on skygazing in his monthly column on how to get started in astronomy.

“Stars were golden unicorns neighing unheard through blue meadows.” – William Faulkner.

The word solar is associated with so many aspects of our daily life – solar power, solar panels, and even in medieval times some rooms were called a solar (although that is more related to the Latin word solus meaning alone rather than solaris which relates to our Sun).

When we think of the Solar System it may conjure up different things to us individually.

Whether we think about the planets, asteroids, moons, comets, meteors etc. the one thing that they will all include is the Sun.

The Sun isn’t a solid mass but a fluid sphere with a dynamic atmosphere. The Sun provides us with all the light and energy needed for us to exist.

Many spacecraft have been sent towards it to study how it functions and, of course, the biggest problem is how the heat and radiation may affect such craft.

The Sun has been revered and worshipped by many civilisations all over our planet. Many myths and legends are associated with it, which all demonstrate that it has been a major influencer for a long time.

It is well believed that the Sun was formed first in our solar system some 4.5 billion years ago with the planets being created from the dust that was left over. That must have been a lot of dust!

The planets and their moons all lie in a similar plane and orbit the Sun in the same direction. They may have been in exactly the same plane at the time of creation but it is thought that collisions and gravity shifted them a small amount so that they are out of precise alignment.

This is the reason for the phenomenon that is due to occur on Tuesday, October 25, 2022, between 10.08am and 11.52am.

On that date we will be able to experience a partial solar eclipse.

The Moon is due to pass in front of the Sun and during this time the Sun will appear to have a chunk bitten out of its side.

Before we go any further, we must stress that you must not look directly at the Sun as it can cause irreparable damage to your eyes.

By a strange coincidence, the Sun is approximately 400 times further away from us and 400 times larger than the Moon.

This means that, when exactly aligned, the Moon will cover the surface of the Sun as we observe it from Earth.

From our location in Hertfordshire, on October 25 the shadow created by the Moon will not cover the Earth completely, so this will be a partial eclipse.

The Moon’s shadow is not large enough to cover the entire surface of the Earth even if it is better aligned, so a total eclipse will cover only a part of the Earth’s surface with areas close by experiencing a partial eclipse.

The last total eclipse visible from the UK was in August 1999, which was visible from Cornwall and Devon. The next one visible from the UK will be 23rd September 2090, so put that date in the diary!

If you are fascinated by eclipses, then perhaps you would like to join us for the next meeting of the Hertford Astronomy Group.

It is on Wednesday, October 12, either at the University of Hertfordshire site in College Lane, Hatfield, or on Zoom.

Details can be found on https://hertsastro.org.uk – new faces are welcome.

A photo of the last partial eclipse visible in the UK in June 2021

The photo was taken with a cheap mobile phone attached to a not so cheap solar telescope from my tree shrouded garden in Welwyn Garden City.

The Moon can be seen obscuring the light from the Sun.

If you look very closely at the edge of the Sun, you might even spot some solar prominences.

Alan with his set up to photograph the eclipse in June 2021.

The telescope is connected to the tripod with a special mount that automatically tracks the position of the Sun.

The telescope is a PST – Personal Solar Telescope – and is specially manufactured for solar observation.

Never use a telescope to observe the Sun, unless it is one like this or has proper solar filters fitted. If in doubt – don’t!


Photo of the month – The Rosette Nebula

Invisible to the naked eye, it is hard to believe that this nebula has an angular size of 1.3 degrees.

That means it takes up about as much space in the sky as 5 Moons arranged in a domino pattern would.

Taken by club member Martin Weston from his garden in Wheathampstead, the Rosette Nebula is about 130 light years across and it is about 5,200 light years away from us in the constellation of Monoceros – the unicorn.