One of the most notable asterisms in the sky gained its fame just over 30 years ago. Called Kemble’s Cascade after the Franciscan friar from the Canadian prairies named Lucien Kemble, this group tumbles gracefully through the far-northern sky just east of Cassiopeia, ending at the open cluster NGC 1502. This is a perfect target for quick observation by northern observers on a cold winter’s night.
Here’s how to see this pretty little asterism for yourself.
To find Kemble’s Cascade, sweep due east of the W-shaped Cassiopeia a distance equal to the span of the “W” itself, about 10 degrees (the width of your fist held at arm’s length). The group consists of a 2.5° span of some 20 stars in a nearly-straight line running northwest to southeast. The stars are of 7th to 9th magnitude, with a single 5th-magnitude star mid-span. You need binoculars or a wide-field telescope to see this group. See the image above to see what to look for. The asterism lies over the border of Cassiopeia in the constellation Camelopardalis, the Giraffe. Because of its proximity to the north celestial pole, this object is not visible to observers well south of the equator.
The open star cluster NGC 1502 lies at the southeastern end of the cascade. This open cluster reveals some 25-30 stars in a triangular pattern in a small telescope at 60-70x.
This asterism was first noted by Lucien Kemble as he scanned the sky with 7×35 binoculars. Kemble sent his description of this asterism to the great astronomy writer Walter Scott Houston at Sky and Telescope magazine. Houston published Kemble’s remarks in December of 1980, and referred to the group as Kemble’s Cascade from there on.
Lucien Kemble was a respected deep-sky observer in the Royal Astronomical Society of Canada (RASC). In addition to his religious training and duties, Kemble diligently observed the deep sky, recording his observations of more than 5,000 objects with his 11″ telescope under the clear skies of Saskatchewan. Kemble passed away in 1999.
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