M67
M67 - Click here for full resolution
M67 (Messier 67), also known as NGC 2682, is an open star cluster located in the constellation Cancer. It is one of the oldest known open clusters, with an estimated age of around 4 billion years, making it significantly older than most other open clusters in the Milky Way. M67 is situated approximately 2,700 light-years from Earth and contains over 500 stars, many of which are similar in age and composition to the Sun. This similarity makes M67 a valuable object for studying stellar evolution and the properties of Sun-like stars. The cluster spans about 12 light-years in diameter and is notable for its dense core and relatively rich population of stars. M67 was discovered by Johann Gottfried Koehler in 1779 and later cataloged by Charles Messier.
source: DeepSeek
NGC/IC:
Other Names:
Object:
Constellation:
R.A.:
Dec:
Distance to Earth:
App. Magnitude:
Transit date:
Tr. Alt (Oria, Spain):
NGC2682
n.a.
Open cluster
Cancer
08h 51m 18s
+11° 48.0′
2,700 ly
n.a.
20 February
64º S
Conditions
M67 is best visible during Winter. During this time It reaches altitudes over 60°, when observed from the remote observatory at IC Astronomy in Oria , Spain. M67 was photographed from the observatory in Spain over 5 nights, during the full moon periods in mid January and mid February 2025.
Equipment
The default rig at the observatory was used. The core of this rig is a Planewave CDK-14 telescope on a 10Micron GM2000 mount, coupled to a Moravian C3-61000 Pro full-frame camera. The RoboTarget module in Voyager Advanced automated the process to find optimal time-slots during astronomical night.
Telescope
Mount
Camera
Filters
Guiding
Accessoires
Software
Planewave CDK14, Optec Gemini Rotating focuser
10Micron GM2000HPS, custom pier
Moravian C3-61000 Pro, cooled to -10 ºC
Chroma 2” Luminance, Red, Green and Blue unmounted, Moravian filterwheel L, 7-position
Unguided
Compulab Tensor I-22, Windows 11, Dragonfly, Pegasus Ultimate Powerbox v2
Voyager Advanced, Viking, Mountwizzard4, Astroplanner, PixInsight 1.9.2
Imaging
M67 is a typical broadband object and default exposure times for a full moon situation were used. This means 3 minutes for luminance and each of the Red, Green and Blue filters. The total exposure was 8.5 h. All subs taken were of sufficient quality and made it into the final stack.
Resolution (original)
Focal length
Pixel size
Resolution
Field of View
Rotation
Image center
9408 × 6288 px (60 MP)
2585 mm @ f/7.3
3.8 µm
0.30 arcsec/px
47' x 31'
-0.098°
RA: 8h 51m 23.230s
Dec: +11° 48’ 53.56”
Processing
All images were calibrated using Darks (50), Flats (50) and Flat-Darks (50), registered and integrated using the WeightedBatchPreProcessing (WBPP) in PixInsight. All further processing was done in PixInsight, including the use of scripts and tools developed by RC-Astro, SetiAstro, GraXpert, and others. For a step-by-step description of the processing techniques applied, see process flow below.
To maintain colour in the RGB image, ArcSinhStretch was applied. An alternative is GHS stretching in ‘Colour’ mode, but often I don’t like the results of stars stretched with GHS. After stretching the RGB image, some of the stars had a bit of a clipped center. This would not be a problem, as luminance would correct for that, but still decided to smoothen the RGB image with convolution before sharpen it all up with the luminance.
Rest of processing followed a very standard pattern.
Processing workflow (click to enlarge)
This image has been published on Astrobin
