NGC 6811 is an open cluster of stars in the constellation Cygnus.  The cluster consists of approximately 70 member stars.  The cluster’s stars have an intermediate age of about 700 million years.  NGC 6811 spans about 15 arc-minuets in diameter.  This is approximately half the diameter of the full moon.  The distance to the cluster is somewhat uncertain.  Current estimates place it between 2940 and 3960 light-years from the Earth.  The cluster stands out from background stars which makes for an excellent visual image in moderate sized amateur telescopes.  The presence of red giant and bright blue stars makes long exposure color images of the cluster a spectacular portrait resembling jewels spread across black velvet.

¹http://cs.astronomy.com/asy/m/starclusters/450560.aspx