Sky Object of the Month – February 2014

Kemble’s Cascade/NGC 1502 – Asterism and Open Cluster in Camelopardis
by Glenn Chaple

In 1980, while scanning a rather vacant area of the constellation Camelopardis with 7 X 35 binoculars, Canadian amateur astronomer Fr. Lucian J. Kemble came across “a beautiful cascade of faint stars tumbling from the northwest down to the open cluster NGC 1502.” He reported his finding to Sky and Telescope “Deep Sky Wonders” columnist Walter Scott Houston, who featured the remarkable asterism in the December, 1980, issue. Houston appropriately christened it “Kemble’s Cascade.”

This 2½ degree-long chain is comprised of some two dozen magnitude 7 to 9 stars with a 5th magnitude star at its midpoint. NGC 1502 is visible as a fuzzy patch of light at the southeastern end of the Cascade. This dazzling 8 arcminute-wide open star cluster is comprised of several dozen stars, magnitudes 10 to 11. At its center is the pretty double star Struve 485 ((485), a pair of 7th magnitude stars separated by 18 arcseconds.

Kemble’s Cascade can be found by sweeping your binoculars from beta (() through epsilon (() Cassiopeiae and continuing in a straight line an equal distance beyond. A dark-sky location on a moonless night will help you pick up the fainter Cascade members. Should you decide to view Kemble’s Cascade via telescope, work with a rich-field instrument and an eyepiece that magnifies 15 – 20 times and captures a 3 degree field. NGC 1502 and its embedded double star are best viewed with a boost to 30X or more.

     

Finder chart for Kemble's Cascade and NGC 1502 generated with Sky Tools 2 by Capella Soft; Sketch by Kiminori Ikebe (www.asod.info/?p=1272)

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