Line of Sight Neighbors

M39 and NGC 7082
Sketch and Details by Rony De Laet

The brightest open cluster of Cygnus is Messier 39. With a diameter of more than a full moon, M39 is a beautiful binocular object. To find this open cluster, just drawn an imaginary line from Deneb (Alpha Cygni) to Alpha Lacerta and point your binoculars at the middle of that line. There you’ll find M39 as a large triangular configuration of 6 brighter stars with a dozen fainter ones. While you have this open cluster in your sight, try to find a neighbour of M39: NGC 7082, at one and a half degree to the south. NGC 7082 is rather dim, compared to M39. My binoculars show only a few faint stars in an elongated misty patch of weak unresolved star glow. M39 and NGC 7082 appear to be close companions, but this an optical illusion. While M39 is 830 light-years from us, NGC 7082 is about 5 times further away. With both objects in the field of view, it is not difficult to imagine that NGC 7082 floats far behind M39 through the night sky.

Site : Bütgenbach, Belgium
Date : July 1, 2008
Time : around 23.45 UT
Binoculars : Bresser 8×56
FOV: 5.9°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 3,5/5
Transp. : 4/5
Nelm : around 5.8
Sketch Orientation : N up, W right.
Digital sketch made with Photo Paint, based on a raw pencil sketch.

(Note: if the sketch does look too dark on your monitor, try to darken the room.)