BBC Sky at Night Magazine

Binocular tour

- With Steve Tonkin

1. M29

Although you can easily see this open

cluster in small binoculars, this little object (7 arcminutes diameter) really lends itself to more magnificat­ion. Put Sadr (Gamma (γ) Cygni) at the north of the field of view and the cluster will be near the centre. Depending on your sky conditions, you should see up to 20 stars, including two arcs of brighter ones that form a ‘power station cooling tower’ shape.  SEEN IT

2. NGC 6871

Our next open cluster is brighter and much larger, and contains a lovely variety of star colours. The brightest of these, orange 27 Cygni, is a foreground star however. At 5,100 lightyears, the young blue and white stars of the cluster are more than 60 times as distant. Notice how the brighter stars in the cluster seem to form pairs. The brightest blue star, HIP 99002, is the brightest Wolf-Rayet star visible from the UK.  SEEN IT

3. M27

From Gamma (γ) Sagittae, scan a

little more than 3° in the direction of 15 Vulpeculae where you will find a tiny glowing cloud. This is the Dumbbell Nebula. Initially it will appear rectangula­r but, with patience and averted vision, you should make out the slight narrowing in the middle that gives it its common name. It is 1,360 lightyears away with a diameter of about two lightyears.  SEEN IT

4. Albireo

The meaning of the name Albireo (Beta (β) Cygni) is lost in time, but we know it as the beautiful double star that marks the Swan’s eye. The components are separated by 34 arcseconds, so are a good test of 10x magnificat­ion: you will need to have perfect focus and steady binoculars. Once you have split it, notice the beautiful colour contrast between the golden (mag. +3.1) primary and the azure (mag. +5.0) secondary.  SEEN IT

5. Stephenson 1

Stephenson 1 is a cluster that deserves

to be better known. Delta (δ) Lyrae is a very wide (10 arcminutes) double star with a colour contrast that easily outdoes Albireo. This not a true double: the difference in distance is about 200 lightyears. Our cluster lies immediatel­y southwest of the pair and initially appears as a granular patch of sky, but patience and averted vision will help you to resolve the brighter stars.  SEEN IT

6. M57

Our second planetary nebula is a challenge. The mag. +9.5 Ring Nebula, M57, lies almost mid-way between Sheliak (Beta (β) Lyrae) and Sulafat (Gamma (γ) Lyrae), making it easy to locate, but it’s less easy to identify. You are seeking what looks like a faint defocused star, but don’t expect to see the hole in the ring.  SEEN IT

Tick the box when you’ve seen each one

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