Astro
Images
Designations: NGC6939
Object Type: Open
Cluster
Constellation: Cepheus
RA: 20
h 31.4 m
Dec: +60 deg 09 m
Visual
Magnitude: 10
Size: 5 min
Distance: 4000 light years
Discoverer:
unknown
Near the extreme western edge of Cepheus is the open cluster NGC6939. Through
a small telescope it appears about 5' in diameter and shines with a total light
equivalent to a 10th-magnitude star. In their book Revue des constellations,
R.Sagot and J.Texereau describe NGC6939 as : "Not very notable in a 3-inch
18 -power refractor; a round milky spot with very faint stars in a 3 3/4 inch
at 45X." In the catelogs, this open cluster is listed as being fainter
than NGC188, but is far easier to pick up because the stars are concentrated
in a smaller area of sky. A 10-inch shows a springling of stars. And
only about 1degree to the southeast, just over the border into Cygnus, is the
fine galaxy NGC6946. This spiral is easily seen
in even small telescopes. It shines at 9th magnitude and is roughly 10'
across.Telescope: TMB 152 mm APO
Refractor
Focal Length:
1200 mm with 0.8x reducer (960 mm)
Mount: Takahashi NJP 160
Camera:
Starlight XPress
MX916
Exposure:
Multiple 20 second
exposures
Other: SBIG STV guider, Optec
Intelligent Filter Wheel
The visual descriptions of NGC6939 was written by Walter Scott Houston
in the book Deep-Sky Wonders. Page 174. ISBN number 0-933346-93-X
Astro
Images
doug@dougsastro.net
Copyright(c) 2007 Doug
Sanqunetti. All rights reserved
