Off the beaten path, to dazzling star clusters

The following sun and moon data for Nov. 6, 2008 is provided by the United States Naval Observatory.

Sunrise: 6:38 a.m.

Sunset: 5:05 p.m.

Moonrise: 1:23 p.m.

Moonset: 12:26 a.m. Nov. 7.

Moon phase: The moon is waxing gibbous with 56 percent of the visible disk illuminated.

Although the much celebrated Pleiades star cluster is one of the easiest and prettiest naked eye objects to locate in our night sky, the rich starfields between Perseus and Cassiopeia offer the backyard stargazer a chance to venture off the beaten path to locate a pair of lesser known, but no less dazzling star clusters.

Known as the Double Cluster in Perseus, or NGC 869 and NGC 884, the clusters are home to hundreds of stars well within the naked eye threshold, but that show with stunning beauty through binoculars or a small telescope. Each cluster covers an area roughly equal to the full moon.

At about 200 stars, and at magnitude 4.3, NGC 869 is the brighter and richer of the pair, while the stars in NGC 884 (magnitude 4.4) appear more diffuse and scattered. The pair appear side by side and are separated by 1/2 a degree.

Both star clusters lie about 7,200 light years away, and in astronomical terms are relatively young — a mere few million years old.

To the naked eye, the double cluster appears as a faint hazy patch of light, and it takes binoculars or a small telescope to really make the clusters pop. And better yet, low power optics will allow the viewer to resolve both clusters in the same field of view, which isn’t always the case with high power optics.

On dark moonless nights and through the eyepiece of a small telescope or through binoculars, stargazers will find numerous hot, blue white stars blazing against a vast sea of black. Around NGC 884, several red giants smolder in hues of amber, ochre and ruddy orange. Careful stargazers will also note a delicate curving chain of stars leading northward towards a large starry patch know as the cluster Stock 2.

To locate the famous Double Cluster in Perseus, stargazers can venture outdoors any clear night in November between eight and 10 p.m. Once outside, stargazers should face north, looking high in the sky for five bright stars which, if connected by lines, trace out a slightly squashed capital letter ‘M’. This is the constellation Cassiopeia — named for the ancient queen of Ethiopia. Then, just off to Cassiopeia’s right is the sprawling constellation representing the Greek hero Perseus — about midway between the two constellations lies the double cluster.

Once stargazers have explored the double cluster, they need simply to shift their gaze away from Perseus to the east where they will find a familiar sight — the lovely Pleiades, or Seven Sisters.

james@pagosasun.com