IC 4665
Open Cluster IC 4665
in Ophiuchus
Right Ascension | 17 : 46.3 (h:m) |
---|---|
Declination | +05 : 43 (deg:m) |
Distance | 1.4 (kly) |
Visual Brightness | 4.2 (mag) |
Apparent Dimension | 70 (arc min) |
IC 4665 is a very conspicuous, coarse star cluster in the opera glas, but
difficult to detect in the telescope so that neither Messier nor one of the
Herschels found it. The Sky Catalogue 2000.0 gives 30 member stars, the
brightest of which is of 6.86 magnitude, a Trumpler type of III 2 p, and
an estimated age of 36 million years. At a distance of 1,400 light years,
IC 4665 is approaching us at 12 km/sec.
IC 4665 has been discovered by the Swiss astronomer
Philippe Loys de Cheseaux, according to the
Webb Society Deep-Sky Observer’s Handbook, Volume 3 (Open and Globular
Star Clusters), p. 3.
In John Caldwell’s Best Sky Objects list.
Astronomical League’s Deep Sky Binocular Club List.
Last Modification: 8 Mar 1998, 19:30 MET