While I waited for M39 to be visible beyond my neighbors tree, I spent a little time on Messier 29 starting around 00:00. This is the first time I imaged M29 with my William Optics FLT91 and the ASI2600MCP.
Messier 29 (M29) is an open cluster located in the constellation
Cygnus, the Swan. The cluster has an apparent magnitude of 7.1. Messier 29 is too faint to be spotted by the naked eye, but can be seen in binoculars. It is best observed in telescopes at the lowest powers. The cluster lies at an approximate distance of 4,000 light years from Earth. It has the designation NGC 6913 in the New General Catalogue.
Messier 29 is located in the vicinity of the bright supergiant star
Sadr, Gamma Cygni, which marks the intersection of the
Northern Cross, a familiar
asterism in the
summer sky. With a visual magnitude of 2.23,
Sadr is the second brightest star in
Deneb. M29 can be found 1.7 degrees to the south and a little east of
Sadr. It lies in a rich, crowded region of the Milky Way.Messier 29 is relatively small, occupying an area of 7 arc minutes in the sky, or a quarter the size of the full Moon. The cluster has a linear diameter of only 11 light years.It is classified as Trumpler class III, 3, p, n, which means that it is a detached cluster without noticeable concentration (III), it contains both bright and faint stars (3), it has fewer than 50 stars (p), and there is nebulosity associated with it (n). The nebulosity around the cluster can be seen in photographs.Messier 29 is approaching us at 28 km/s. The cluster is part of the Cygnus OB1 association, a group of stars that share a common motion, age and place of origin.
The five hottest members of M29 are giant stars belonging to the spectral class B0, about 160,000 times more luminous than the Sun. The estimated age of the cluster is 10 million years. There are six stars in M29 that are brighter than magnitude 9.5. The brightest one has a visual magnitude of 8.59.The cluster’s brightest stars form a quadrilateral and another three form a triangle, located just to the north of the quadrilateral, giving M29 the shape of a squashed dipper. This shape is visible in 3.1-inch telescopes.Without the dust of the Milky Way obscuring the cluster, the stars in M29 would appear about 1,000 times brighter. The cluster’s light is blocked by the material that was around when the stars were still forming.
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