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NGC 663

Open Cluster Excellent (62/100)
NGC 663 OpenCluster Cas Visible Level 1 Naked eye / Binoculars - Wide field preferred
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Properties

Magnitude 7.1
Angular Size 6.0′
Cl, B, L, eRi, st pL

Position & Identifiers

RA 01h 46m 00.0s
Dec +61° 15' 00.0"
Constellation Cas
Catalog NGC 663

Visibility

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Eyepiece View

108x TFOV: 0.5° Lim. mag: 13.3
N E

NGC 663 · 6.0′ diameter · N up, E left

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About NGC 663

Description

NGC 663 is a bright, rich open cluster in Cassiopeia, about 6,850 light-years away. It contains over 400 stars spread across 16 arcminutes, with many hot blue B-type stars and several red supergiants.

Observing Tips

An easy and rewarding target, visible in binoculars as a hazy patch and stunning in small telescopes. A 4-inch scope at 50-80x reveals dozens of stars. Circumpolar from northern latitudes, best placed in autumn.

History

Discovered in 1654 by Giovanni Battista Hodierna. Independently found by William Herschel in 1787. One of the finest open clusters in Cassiopeia.

Fun Facts

NGC 663 is only about 20-25 million years old. It contains an unusual number of Be stars — rapidly rotating hot stars with circumstellar disks — making it ideal for studying this phenomenon.