Orion is proud to partner with BBC Sky at Night Magazine, the UK's biggest selling astronomy periodical, to bring you this article as part of an ongoing series to provide valuable content to our customers. Check back each month for exciting articles from renowned amateur astronomers, practical observing tutorials, and much more!
Will Gater takes us on an observing tour across the sparkling summer night skies.
Summer's balmy nights are short but they pack in some glorious celestial sights. There are many deep-sky objects nestled in the rich star fields of the Milky Way and these will be our destinations on this seasonal star hop. The best time to take this tour is in the last week of June, when the Moon is out of the way. You can choose whether to spread the 15 objects here over a few nights, or observe them all in one. If you feel like doing them in a single session, to make maximum use of the darkness during June's short nights we've chosen a route that takes you through the 15 in the order that they reach their highest point in the sky.
Let's kick off our observing session over in the western sky just after midnight. Hopefully the Moon isn't around and there are hours of clear skies ahead. Mag. +0.2 Arcturus (Alpha Bo÷tis) is blazing away and it's the signpost we need to find our first object, globular cluster M3 in Canes Venatici. Once you've found Arcturus, imagine a line between it and mag. +2.9 Cor Caroli (Alpha Canum Venaticorum). The cluster is just less than halfway along this line.
We've got a bit of a trek to our next object, the spectacular globular cluster M13 in Hercules. Thankfully we can get there with a few simple star hops. Probably the easiest method, from M3, is to use mag. +3.6 Rho and mag. +3.5 Delta Bo÷tis as pointers. Scan along a line from Rho Bo÷tis through Delta Bo÷tis for just over 27░ and you'll come across M13. The cluster is easily visible in binoculars from dark skies and through a small scope it appears as a fuzzy ball of faint light; larger aperture scopes will fare better at resolving the cluster's myriad stars.
Once you've enjoyed M13 it's time to move to another globular cluster, M92, which is about 9.5░ away. It's not as impressive as M13 in binoculars, but it's fairly easy to locate nevertheless. Just sweep along a line between M13 and mag. +3.8 Iota Herculis. You can also find the cluster with a telescope through a series of simple star hops: head northeast from mag. +3.1 Pi Herculis to mag. +4.6 69 Herculis and then onto mag. +6.0 HIP 84656, mag. +7.4 HIP 84559 and finally mag. +6.8 HIP 84118, which is just over 1.5░ from the cluster.
4. Epsilon Lyrae
Having admired three fine globular clusters we're going to switch to a completely different type of object, the wonderful multiple star system of Epsilon Lyrae. From M92, head eastwards towards brilliant mag. 0.0 Vega (Alpha Lyrae). From Vega it is only a short hop to Epsilon Lyrae, which makes a triangle along with Vega and mag. +4.3 Zeta Lyrae. Epsilon Lyrae is most definitely a telescopic object. With a medium to high power eyepiece and a good-sized scope you should have little trouble seeing the two pairs of stars in the system.
5. The Ring Nebula
While in Lyra, there's one object that we really must visit and that's the charming Ring Nebula, M57. This is what's known as a planetary nebula, formed when a star like our Sun ejected its outer layers towards the end of its life. It appears as a little grey ring through the eyepiece. To find it we don't have to go far, though you will need a telescope and a medium-power eyepiece to see it well, as its angular diameter is rather small. You'll find M57 about 70 arcminutes along a line between mag. +3.3 Sulafat (Gamma Lyrae) and mag. +3.5 Sheliak (Beta Lyrae).
It's time to head south from Lyra and into Sagittarius, and the beautiful Milky Way star fields in and around it. At the end of the month, the Milky Way will be low in the south at about 01:00 BST (00:00 UT). Our first object here is magnificent globular M22. To find it, first locate the famous Teapot asterism. The handle of the teapot is the key to finding M22. Imagine a line from mag. +3.3 Tau Sagittarii towards mag. +2.1 Nunki (Sigma Sagittarii). If you extend this line for about 5░ beyond Nunki you'll reach the cluster.
7. The Lagoon Nebula
Next on our tour of this part of the sky is the wonderful Lagoon Nebula, M8. There are several ways you can go about tracking it down. Under dark skies it's visible to the naked eye, so if you're using binoculars you should be able to pick it out fairly easily about 6░ above the 'spout' of the Teapot asterism. If you're using a telescope you'll find the glowing nebula and its sparkling star cluster by slewing roughly 7░ to the west of M22. If you get stuck, remember that the nebula forms a rough isosceles triangle with mag. +2.8 Kaus Borealis (Lambda Sagittarii) and mag. +3.8 Mu Sagittarii.
Heading away from the Teapot asterism, we're now traversing some of the dark dust lanes that criss-cross this region of the Milky Way. We're going in the direction of an exquisite open cluster, made of some 150 stars, catalogued as M23. If you're using binoculars, scan a line from Mu Sagittarii to mag. +3.5 Xi Serpentis. You'll find M23 just less than halfway along. With a small telescope you can star hop from the Lagoon Nebula to the glittering M23 by using four stars as waypoints: mag. +5.8 HIP 88298, mag. +6.3 HIP 88760, mag. +6.8 HIP 88362 and mag. +7.5 HIP 88297.
From M23 we're going to cut right back across the band of the Milky Way to another lovely open cluster, M25, which is also in the constellation of Sagittarius. As you scan east across the sky with binoculars, take a moment to admire the stunning, densely packed star fields located roughly halfway between M23 and M25. Finding M25 with a small telescope is also fairly easy: simply point your finderscope at the 5th-magnitude star HIP 90806 and you'll find the glittering stars of M25 sitting around 45 arcminutes to the south of it.
10. The Eagle Nebula
Our final object on this leg of the tour is located a little higher up in the sky. It's the Eagle Nebula, M16. To get there we need to jump across the border from Sagittarius into the neighboring constellation of Serpens. Start by tracking roughly north from M25 to mag. +4.7 Gamma (g) Scuti. Once there, move west and up a little using mag. +6.7 HIP 90281 to guide you toward the nebula. With a small telescope you should have no problem seeing the cluster of stars in M16 and maybe a hint of the nebulosity itself.
11. The Wild Duck Cluster
We're now entering the third and final leg of our tour, which we begin in the constellation of Scutum, the Shield. This beautiful region of the summer night sky is home to edge of the Scutum Star Cloud and can be seen easily in binoculars. For a truly breathtaking view, use a telescope with a low-power eyepiece so you can really appreciate the open cluster and its starry environs.
12. The Coathanger
To get to our next object we're going to meander our way up the band of the Milky Way. The Coathanger, also known as Brocchi's Cluster, is a lovely grouping of stars that, you guessed it, looks like a coathanger — albeit an upside down one. To reach it from M11, use binoculars to work your way along the rich star fields in Aquila until you get to mag. +0.8 Altair (Alpha (a) Aquilae). Using Altair and the nearby mag. +2.7 Tarazed (Gamma (g) Aquilae) as pointers, head slightly northwest for about 12.5░. Dark skies and a good pair of binoculars are all you need to enjoy this gem.
13. The Dumbbell Nebula
Next up is the fascinating Dumbbell Nebula, M27, which sits in the constellation of Vulpecula. We don't have far to go, but we will need a change of equipment, as a small scope is the best instrument for observing this planetary nebula. There are ways you can star hop to M27, but an easy one is to simply point your scope's finder at the 3rd-magnitude Gamma Sagittae and track north for just over 3░. In a small scope M27 looks like a smudge of light, but in 6-to 8-inch instruments its dumbbell shape becomes much more obvious.
If you've reached this point having observed all the objects so far in one night, we salute you! Your reward will come in the form of one of the most beautiful double stars in the whole night sky, Albireo (Beta Cygni). Albireo is 3rd-magnitude, meaning it is easily visible to the naked eye. It sits at the head of Cygnus, the Swan, which is marked out by a large 'cross' of bright stars with mag. +1.3 Deneb at one end and Albireo at the other. Through a telescope, at high magnification, the two stars sparkle gold and blue — a wonderful sight on a warm summer evening.
We're now at the end of our journey and chances are, if you've been observing all night, the sky is now starting to lighten. We'll end our tour across the summer sky by looking at a lovely, if often overlooked, open cluster: M39. To find it with binoculars follow the body of Cygnus all the way from Albireo to bright Deneb, passing mag. +2.2 Sadr (Gamma Cygni) as you go. From Deneb, imagine a line running all the way to mag. +3.8 Alpha Lacertae in the head of Lacerta, the Lizard. M39 is situated almost exactly at the midpoint of this line.
Summer Astrophotography: Objects to Photograph in This Season's Night Skies
The nights may be short at this time of year but that doesn't mean there aren't plenty of imaging opportunities. Noctilucent clouds are extremely photogenic; a DSLR or compact camera on a photographic tripod should capture them well. Using a wide-angle lens and an exposure of between two and 10 seconds should be perfectly sufficient to reveal most displays.
The summer Milky Way in the constellations of Sagittarius, Scutum, Scorpius and Ophiuchus is also a fine photographic target in June. If you're just starting out in deep-sky astrophotography this region offers many bright and beautiful objects to cut your teeth on; the Lagoon Nebula, M8, is a good example, though you will need a clear southern horizon and excellent transparency for the best images of it.
For more experienced imagers, fainter objects such as the Cocoon Nebula (IC 5146) in Cygnus and the Iris Nebula (NGC 7023) in Cepheus provide a satisfying challenge. If you use narrowband filters in your deepsky imaging setup, old favorites such as the Eastern Veil Nebula (NGC 6992), the Witch's Broom Nebula (NGC 6960) and the Crescent Nebula (NGC 6888) — which are all in Cygnus — are also well placed this month.
Keep a close eye out for these high-altitude electric blue displays.
The twilight skies of the summer months are occasionally adorned with beautiful, glowing wisps of light known as noctilucent clouds. These polar mesospheric clouds, to give them their scientific name, reside high up in our atmosphere at an altitude of around 80-85km. They are clouds of minute ice crystals and it is their great height that causes them to shine — 'noctilucent' simply means 'night shining'.
While ordinary clouds, much lower down in our atmosphere, appear silhouetted against the glow of twilight, the high altitude of noctilucent clouds means they are still illuminated by the Sun, and so scatter the sunlight down towards us on the ground. It's thought that the tiny ice crystals may form on microscopic pieces of meteoritic dust, deposited into our atmosphere by the countless meteors that zip through this region.
Noctilucent cloud displays are usually seen in the UK during late May, June, July and early August. Unfortunately, predicting when a good display will be visible is not easy, so your best bet is to be vigilant and look out for them during the hours after sunset or before sunrise throughout the summer. From the UK, it's the northern horizon that you need to monitor closely for any possible noctilucent cloud activity. Some displays can be very weak and may only show up on camera, while others are bright and easily visible to the naked eye as bluish-white ribbons of light, perhaps containing striking ripple or tendril-like structures.
They are a wonderfully dynamic phenomenon and appear to change minute by minute — some displays look like flowing waves of light crashing over the horizon. Binoculars, or a fixed camera taking still images every five to 10 seconds, will help you pick out any changes in shape and structure, but be very careful not to accidentally observe the rising Sun.
About The Writer
Will Gater is an astronomy writer and journalist. He also appears on TV and radio to talk about space. Find him on Twitter: @willgater
Copyright ę Immediate Media. All rights reserved. No part of this article may be reproduced or transmitted in any form or by any means, electronic or mechanical without permission from the publisher.