| Open
Cluster
Melotte 223, Collinder 403, Raab 139, and OCL 155 Visual Magnitude: 9.5 Apparent Diameter: 5' Minimum requirements to view: 4-inch telescope under suburban skies |
NGC 6819 is a nice small open cluster near the Cygnus/Lyra boundary. It contains about two dozen stars from 10th to 12th magnitude within a 5' circle. Dark skies and a large scope will reveal many more fainter stars as well.
In my 18-inch f/4.5 Dob I see an irregular smattering of bright stars overlapping a larger smattering of much fainter stars. The impression is as if we are seeing two clusters, one close and one far away.
About 7000 light years distant, these stars formed together from a giant interstellar molecular cloud complex around 2.3 billion years ago. That makes them a little more than half again as old as our solar system and the earth.
The view in a 6" at 50x. North is down and east is right.
This view is taken from the Digital Sky Survey and shows a 1/2o field.
| Millennium
Star Atlas Vol II Chart 1129
Sky Atlas 2000 Chart 8 Uranometria 2000 Vol I Chart 84 |
