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C1

NGC 188

OpenCluster Cepheus Mag 8.1

Object Data

Catalog Designation
C1
Type
OpenCluster
Constellation
Cepheus
Magnitude
8.1
Right Ascension
00h 44m 24.0s
Declination
+85° 19' 58.8"
Distance
5,400 light-years
Angular Size
14
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About C1

Description

NGC 188 is one of the oldest known open clusters in our galaxy, estimated at about 6.8 billion years old. Located in Cepheus near the north celestial pole, it lies roughly 5,400 light-years away and contains around 120 stars spread across 14 arcminutes.

Observing Tips

A challenging target requiring at least a 6-inch telescope to resolve individual stars. Located just 4 degrees from Polaris, it is circumpolar from most northern latitudes and can be observed year-round. Best seen at medium power (100-150x).

History

Discovered by John Herschel in 1831. Its extreme age makes it one of the most studied open clusters. Patrick Moore selected it as C1 for his Caldwell catalog, published in 1995 as a complement to the Messier catalog.

Fun Facts

At nearly 7 billion years old, NGC 188 is older than our Sun. Its survival is remarkable because most open clusters are torn apart by gravitational interactions within a billion years. The cluster orbits high above the galactic plane, which may explain how it avoided disruption.

Community Photos (1)

Credit: Kush.Chandaria. License: CC BY-SA 4.0. (Wikimedia Commons)

Credit: Kush.Chandaria. License: CC BY-SA 4.0. (Wikimedia Commons)

Skybred Mar 2, 2026