Binocular tour
Perseus’s double and Cassiopeia’s triple vie for your attention in the February sky
Tick the box when you’ve seen each one
find an almost straight line of 15 8th-magnitude stars with a 5th-magnitude one in the middle. It is named for the Canadian amateur Father Lucian Kemble, who publicised it after first observing it in 1979 with 7x35 binoculars. SEEN IT
3 MELOTTE 15
15x Another OB association of even younger 70 (only 1.5 million years old) blue supergiant stars, in 15x70s Melotte 15 appears as a large but sparse open cluster. You may notice that the brightest stars form a chevron near the centre of the cluster and that, even with averted vision, only a few more fainter stars can be seen scattered throughout it. Unless you have exceptional skies, do not expect to see even a hint of the nebulosity (IC 1805, the Heart Nebula) sculpted by the stellar winds from these stars. SEEN IT
4 THE DOUBLE CLUSTER
10x Extend a line from mag. +2.2 Gamma 50 Cassiopieae through mag. +2.7 Ruchbah (Delta Cassiopeia) for double the distance
5 THE MUSCLEMAN CLUSTER
10x From the part of the Double Cluster that is 50 nearest to Cassiopeia, there is a 2° chain of 8th-magnitude stars to the north, leading to Stock 2, the Muscleman Cluster. This large faint cluster gets its name from the pattern of its 8thand 9th-magnitude stars, which have the form of a stick man in a muscle-flexing bodybuilder pose, apparently hauling this chain of stars away from the Double Cluster. This is a line-of sight effect: Stock 2 is only 1,050 lightyears away, compared to the 7,200 and 7,500 lightyears of the components of the Double Cluster. SEEN IT
6 NGC 663, 654 & 659
15x Perseus has the Double Cluster, but 70 Cassiopeia has a triple! Look 1º left of the middle of an imaginary line joining Segin and Ruchbah and you will easily find the richest of these, NGC 663, the four brightest stars of which are separated into pairs. Just under 1º to the north-northwest is NGC 654, a small cometshaped patch of light just next to a mag. +7.3 star. The poorest of the trio is NGC 659, a tiny ghostly glow that may need averted vision to see. It sits 1.2° south of NGC 654, near mag. +5.8 star 44 Cassiopieae. SEEN IT