Summer Solstice

The Night Sky

June 2021

Summer Solstice (June 21st) is the longest day of the year where the tilt of the Earth (for us) is inclined towards the sun, resulting in over sixteen and a half hour of daylight. You might think that this would wash out most things for us to see this month. In a way that is true, but if you are prepared to stay up a little longer there is plenty to see! No matter what you use to observe there is something for everyone.

Observing with your Eyes.

The morning of 10th June will see a partial solar eclipse across the UK. About 40 % of the disc of the sun will be blocked out by the moon at 10.15am. The next total solar eclipse visible in the UK will be 23rd September 2090!

For about a month either side of the Summer Solstice there is a chance to see something that you cannot see at any other time of the year. They are not common but you may get lucky. These are the very distinctive noctilucent clouds, electric blue and can be seen in a northerly direction (in the direction of Embsay Crag) after sunset when the brightest stars come into view before it gets completely dark.

They are, in fact, ice crystals so high up in the atmosphere (50 miles) that they are still able to catch the sunlight despite the sun having set.

Observing with Binoculars.

The Virgo Cluster is really the best concentration of galaxies for you try to view and each galaxy should have an article dedicated to itself. But here we have over 150 major spiral and elliptical galaxies (roughly 2000 in total).

Some of them will appear to be smudges but they are galaxies just like our own Milky way.

Over time we will look at some galaxies in more detail but for now, like being offered a paper bag full of tasty sweets, gorge yourself!

Observing with a Telescope.

During the time of a new moon is perhaps the best time to observe faint objects and this month it is on 10th June. One of my favourite objects to observe is in the constellation of Lyra.

In Greek mythology a great musician played a lyra when accompanying Jason and the Argonauts. What a great tale immortalised in the sky and many will remember the film usually over Christmas! When I first explored Lyra I saw a very special object that made me gasp. Instead of seeing the usual stars and pinpricks of light, in full view was what appeared to be a polo mint!

What I had stumbled upon was the wonderful Ring Nebula or M57. Around its edges is a distinctive red coating and if you are lucky you may pick out a blueish tint around the inside of the ring. It is quite easy to find as it is close to the bright star Vega. M57 is the result of a massive explosion about 8000 years ago. It is a star like our own in its final stages and what you will see is the aftermath. Its material is blown outwards to reveal a space where a sun like ours used to be. The star has now become a ‘White Dwarf’ so much smaller that only the most powerful telescopes can spot what is left.

Clear Skies

Milan Davidovic

The Greatest Show!

The Night Sky

May 2021

Over the past year or so, if you looked up into the night sky on a dark Embsay evening you may have been able to shake off for a moment the unsettling and distressing events of the pandemic around you. The calmness and familiarity of the patterns passing across the sky for me was as reassuring and comforting as an old friend, perhaps highlighting that in the huge timescale of the universe this period was just a blink of the eye. I’m glad that I am again able to share some of the excitement and wonder of what is the greatest show not on Earth!

If you are new to stargazing and want to develop an interest, then here are a few tips. Binoculars are a good start to the hobby. Portable, a good wide view and easy to use. There are also so many free apps and charts that you are able to access to help you find your way around the night sky. Become familiar with the position of one star that never seems to move, Polaris or the North Star. Then try to become familiar with four or five patterns or constellations that are always visible. The rest will develop if you succumb to the night sky. I will help you with these simple steps and if not already, appreciate the wonder and what we can all enjoy freely above Embsay.

In astronomy the best instrument to use are just your eyes. So with nothing else starting from the centre of Embsay, find North. This is just to the right of Embsay Crag. Facing in that direction cast your eyes from the horizon to directly above your head. As you do this just over half way up between these two points is a star at the end of what looks like pan shape (Diagram A). This is Polaris, not the brightest star in the sky but everything you see appears to spin around this point anti-clockwise. During this time of year the ‘pan handle’ is pointing downwards late evening. The pan being a pattern called URSA MINOR. It is important to become adept at locating Polaris if you want to find your way around the sky.

Having found Polaris we are going to seek out something that can only be spotted with your naked eyes in a place like Embsay on a moonless, dark clear night. A bit of a challenge!

From Embsay looking in the direction of Bolton Abbey or towards Low Lane you will be facing East. Half way up in the sky this month you will find a keystone shape. (Diagram B) . This is at the centre of a constellation called Hercules. This keystone shape contains what looks like an orb of fuzzy light, called M13 or the Great Cluster in Hercules. This is a globe of half a million stars! It is so far away that it takes 25,000 years at the speed of light for its light to get to us. On November 16th 1974 people on Earth sent a deliberate message towards this Cluster using a powerful radio transmitter. The multitude of suns offered the best chance of being heard by the planets that must be orbiting each sun. A bit of a long shot when you consider that is a 50,000 year return call! I can’t remember the calls I made last week!

M13(The Great Cluster) Image Astrosurf.com

Although the dark nights are shortening and the opportunity to have long periods of darkness are reducing there is still lots to see and I hope I’ll help you develop your interest with these regular articles.

Clear Skies

Milan Davidovic

Photographing the Night Sky.

Your eyes are amazing instruments. If you allow them to adapt to the night sky they will be able to see very dim and distant objects. However, two limiting factors of using your eyes are that you cannot ‘zoom in’ and, once your pupils are at their maximum, you can’t increase the amount of light entering your eye. A camera, however, can do both! Even a modest mobile phone with a built- in camera can zoom in and collect light over a long period and display all of that light in one go with some adjustment and a steady hand. Of course, this means you can see more detail and fainter objects. For example, many people successfully use their mobile phone to take stunning pictures of the Moon. However, if you have a telescope you can put the mobile camera over the eyepiece, turn off the flash, zoom in (no more than x2), touch the screen where the moon is (it will bring up a box), slide the exposure to prevent a blurry image. You’ll need to be steady! You may get lucky and produce an amazing image.

To increase the chances of a better picture you need a tripod or ‘mount’. The latter can be set up so that it moves ever so slightly as the earth turns, in effect stopping stars from appearing to drift (and blur). Although letting the night sky arc across the sky makes a great picture.

With this set up you can open the shutter on your camera for ages, letting in bucket loads of light to display in a single image.

A camera has another trick up its sleeve. It can pick up types of light that your eyes can’t. A camera can pick up wavelengths of light such as infrared beyond your biological limits. (Just for the record, snakes can see infrared light and bees can see ultraviolet light!) Many astronomers tinker with their cameras to remove internal filters that block a lot of light and this makes a huge difference to the light that can be collected in a short time. However, in most cases, after that modification you can’t use the camera for taking ‘normal’ pictures.

If you are lucky enough to travel to a place where the northern lights are visible, here are some useful tips. Get and use a tripod. Without it, you will struggle. In the daylight focus on a very distant object and then turn AUTOFOCUS OFF. For the best results this next bit is technical. You need to get a lot of light into your camera so set the aperture at f/4. Secondly, set the ISO to 800. Finally, set the exposure (how long the shutter is open) to between 5-25 seconds, so experiment. It is best that you use a delayed timer if possible or, better still, a cable release so that you don’t end up shaking the camera as you press the button for your amazing shots!

Don’t forget to put autofocus back on after your session.

Between April 21-22 the annual Lyrids meteor shower arrives just before the New Moon on 23rd. If the weather is clear, we should have a good display of about 18 meteors per hour. Although this is not a huge number they are fast and therefore packed with energy as these particles hit the atmosphere and leave persistent trails. Look NE half way up in the sky late/early morning and they will appear to radiate from this point across the sky.

Planets this month.

Venus passes the Pleiades, a cluster of stars (also known as The Seven Sisters) in the evening between 2-4 April. To catch Mars, Saturn and Jupiter get up early between 15-16 April to get a good view of all 3 low in the SW.