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Sighting the Queen

Cassiopeia offers sparkling binocular treasures.
Harrington
Cassiopeia the Queen is one of the most distinctive constellations in the sky. Its five brightest stars form a W pattern that is easily recognizable by even the most casual stargazer.

In Greek mythology, Cassiopeia was the wife of King Cepheus, monarch in ancient Ethiopia. Nearby in our sky is their only child, Princess Andromeda, whom we visited in my last column. Cassiopeia was banished to the sky after boasting that Andromeda was more beautiful than the Nereids, the female water spirits who accompanied Poseidon, Greek god of the seas. Cassiopeia forever wheels around the North Celestial Pole sitting on her throne, spending half of her time clinging to it to keep from falling off.

NGC457
The Owl Cluster, NGC 457, is a bright star group shaped in a birdlike form. It features the bright foreground stars Phi1 and Phi2 Cassiopeiae.
Ken and Emilie Siarkiewicz/Adam Block/NOAO/AURA/NSF
For most of us, Cassiopeia is a circumpolar constellation, and so it graces our skies at all hours all year long. But this time of year, she appears highest in the evening sky. November is an ideal time to marvel at the many wonderful binocular targets that lie within. There are too many to visit in a single column, but here are a few of my favorites.

Let’s begin by centering on Delta (δ) and Epsilon (ε) Cassiopeiae in the constellation’s W. Since these 3rd-magnitude stars are separated by just under 5°, they should squeeze into the same field through most binoculars.

Just 1° northeast of Delta, we find open cluster M103, the final entry in Messier’s catalog when it was published in 1781 in the Connaissance des temps for 1784. M104 through M109 were added by 20th-century astronomical historians after examining Messier’s unpublished notes.

Messier did not discover M103, however. Like many earlier entries in the catalog, his contemporary, Pierre Méchain, first uncovered it. In this case, he bumped into it just before Messier’s catalog was published. Messier actually never saw it before his catalog went to press.

M103
The rich open cluster M103 appears as a striking arrowhead-shaped cluster of glistening stars.
Anthony Ayiomamitis
Had he the opportunity, Messier would have seen a sparkling collection of stardust set in an arrowhead pattern measuring about 6' across. Marking the tip of the arrowhead is the pretty telescopic multiple star Struve 131. Most studies conclude, however, that the star’s association with the cluster is just a chance line-of-sight alignment. M103 is estimated to be 8,500 light-years away, more than four times farther than Struve 131. Through giant binoculars and telescopes, those stars look like blue-white sapphires surrounding a lone red stellar ruby near the middle.

If Méchain and Messier had more time, they undoubtedly also would have found our next target. Can you spy another faint fuzz 2° northeast of M103? That’s NGC 663, a striking assembly of about 80 faint stars. Those stars shine collectively at 7th magnitude, but remain unresolvable individually through 7x to 10x binoculars. The brightest just peek out from the glow in my 16x70s. Even larger binoculars reveal that the stars appear bunched into two asymmetric clumps. NGC 663 actually stands out better than M103 through binoculars, so be careful not to confuse one for the other.

Our last stop this month is NGC 457, set about 2° southwest of Delta. More than 80 stars call this cluster home, with many visible through steadily braced 10x binoculars if you look carefully. Viewing through 70mm and larger binoculars will reveal that the stars in NGC 457 create a distinctive pattern. Some observers imagine a dragonfly; others a Hopi kachina doll; or even Hollywood’s E.T., the Extraterrestrial. I prefer its common nickname, the Owl Cluster.

NGC663
Some 80 faint stars make up NGC 663, a cluster that stands out well from the Milky Way as seen in binoculars.
Peter and Suzie Erickson/Adam Block/NOAO/AURA/NSF
The owl’s body is drawn from about a dozen stars that shine between magnitudes 9 and 11, with two 10th-magnitude suns marking the tail feathers. Two arcs, each containing about half a dozen suns, form the wings. The east wing is highlighted by a distinctive 8th-magnitude orange star, the brightest member of the cluster. The owl’s dazzling “eyes,” marked by 5th-magnitude Phi1 (ϕ1) and 7th-magnitude Phi2 (ϕ2), are attention-getters. But don’t be fooled. Both are probably foreground stars. NGC 457 is estimated to be about 7,900 light-years away, while Phi1 may lie anywhere from 2,300 to 4,500 light-years away. While that’s a high potential error, it still puts them between us and the cluster. Probably. Still other data suggest that they could actually be at the same distance as the cluster.

Of Cassiopeia, author Garrett Serviss wrote in his 1888 book Astronomy with an Opera-Glass, “Here the Milky Way is so rich that the observer hardly needs any guidance.” This still rings true 130 years later. These three clusters are just the beginning. By sweeping the Cassiopeia “W” with your binoculars, you’ll find treasures in nearly every field.

Until we meet again next month, as autumn fades into winter, remember that when it comes to stargazing, two eyes are better than one.

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