Binocular tour

December delivers an abundance of asterisms and the first of Messier’s vexations

Tick the box when you’ve seen each one

Its short legs are made of fainter stars. I see it as a dachshund viewed obliquely, but apparently John Davis, for whom this asterism is named, saw a beagle. What do you see? SEEN IT

3 LEAPING MINNOW

10x To find our third asterism of this month’s 50 tour, navigate a bit more than 4° east of mag. +2.7 Hassaleh (Iota Aurigae). Here you will find a little group of approximately mag. +5.0 stars, just over 1º across, that includes 16, 17, 18 and 19 Aurigae. In a pair of 10x50s you should see that this group of stars forms the shape of a fish. If you look to the northeast of the Minnow you will see the ‘Splash’, which includes mag. +5.0 Phi Aurigae. Counting the Splash, you should see at least 30 stars. SEEN IT

4 A TRIO OF CLUSTERS

10x Putting Phi Aurigae on the right of the 50 view, you should see two fuzzy patches, one above the centre and the other below. The upper, slightly larger one is the Starfish Cluster,

5 THE CRAB NEBULA

15x We continue the aquatic theme with an 70 object that every amateur astronomer should know of. On 28 August 1758, Charles Messier was seeking the predicted return of Halley’s Comet. He happened upon what he thought was a comet, a tiny (5 arcminute) misty patch 1.1° northwest of mag. +3.0 Zeta Tauri. The patch hadn’t moved a week later, so he knew that it was not the comet, and M1 became the first in his list of objects for comet hunters to avoid. Today we know it is a mag. +8.4 supernova remnant; you’ll need a dark, transparent sky to observe it. SEEN IT

6 NGC 1647

15x Put mag. +0.9 Aldebaran (Alpha (_) 70 Tauri) in the southwest of the view and opposite it you will find the open cluster NGC 1647, also designated Melotte 26. This sparse cluster is easy to identify at low power, and a pair of 15x70s should reveal 20-30 stars against a background glow just under 1º in diameter. Take a closer look at brightest of these stars: you should be able to see that it is actually a double star with a separation of 33 arcseconds and magnitudes of +8.9 and +9.3. SEEN IT