The northern constellation Cassiopeia is clogged with open star clusters that invite inspection with a small telescope. One of the most striking of these clusters is the wonderful NGC 457, also known as the “E.T. Cluster”, because of its resemblance to the famous character from the Steven Spielberg movie, eyes glowing, arms outstretched, ready to give you a big hug.
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Photographs of NGC 457, while impressive, can’t capture the visual appeal of this star cluster. To some, its glowing eyes appear startling and sinister, especially with two strands of starry arms reaching out to grab you. Some observers see this cluster as an owl, a stick man, a doll, or a fighter jet with the two bright stars marking the afterburners. The eyes (or afterburners) are the 5th magnitude star φ (phi) Cassiopeiae and 7th magnitude HIP 6229. It’s likely phi Cass is not really a member of the cluster because its color and position on the HR diagram don’t fit with that of the other members. Satellite data puts the distance of this star at roughly 4,000 light years, whereas the distance to the cluster is some 9,000 light years, though both distances are uncertain.
The whole cluster has a magnitude of about 6.4… right at the limit of visual detection in dark sky. It’s easily visible in binoculars, but you’ll need a telescope to see the E.T. figure. Even a small 2-3 inch scope at 30x-40x will give you a fine view. In an 8-inch scope, about 100 of the cluster’s 200 mostly blue-white members can be seen. One of the stars, HIP 6231 in E.T.’s “armpit”, is an evolved supergiant star that shines with a lovely orange-red glow. Find NGC 457 on a line extended through delta (δ) Cass from epsilon (ε) Cass, just beyond delta. Phi (ϕ) Cass marks the cluster, and it’s just barely visible in dark sky. Phi and HIP 6229 are also a lovely double for binoculars.