Open cluster M29 is one of the original discoveries of Charles Messier, who cataloged it on July 29, 1764.
Messier 29 (M29, NGC 6913) is a rather coarse and less impressive cluster, situated in the highly crowded area of Milky Way near Gamma Cygni, at a distance of 7,200 (most sources including Mallas/Kreimer and Burnham, and agreeing with early estimates or R.J. Trumpler 1930) or 4,000 light years (the latter from Kenneth Glyn Jones and the Sky Catalogue 2000.0). The Night Sky Observer's Guide by Kepple and Sanner gives a deviating value of 6,000 light years - the uncertainty due to inacurately known absorption of the cluster's light.
W.A. Hiltner of Yerkes Observatory, in 1954, found the light of its stars rather polarized by interstellar matter, which is apparently 1,000 times denser around this cluster and may absorb so much light that the cluster would be 3 magnitudes brighter if viewed "freely" or "in the clear"! Also in 1954, Harris reported irregular obscurations of cluster member stars (perhaps by passing interstellar dark matter through the line of sight). |
