NGC 188

Open Cluster NGC 188

(= Caldwell 1

= Collinder 1 = C0039+850)

in Cepheus

Right Ascension	00 : 44.5 (h:m)
Declination	+85 : 20 (deg:m)
Distance	5.0 (kly)
Visual Brightness	8.1 (mag)
Apparent Dimension	14 (arc min)

Perhaps the oldest known open star cluster in our Galaxy, with a calculated age

of over 5 billion years (Alan Sandage’s first estimate was even an age as high

as 24 billion years, while Burnham claims 10-12 billion).

It consists of about 120 stars, the hottest main sequence star of spectral

type F2, the 10 brightest stars being yellow giants of spectral

types G8 to K4 and luminosity class III, apparent magnitudes of about 12-14,

corresponding to absolute magnitudes of 0 to +2.

As its Caldwell number indicates, NGC 188 is situated very close to the North

celestial pole.

---

Hartmut Frommert

([email protected])

Christine Kronberg

([email protected])

Last Modification: 29 Mar 1998, 13:15 MET