Messier 67 or M67 (also designated NGC 2682) is an open cluster in the constellation Cancer. It has an apparent visual magnitude of 6.1 and its angular diameter is 30 arc-minutes. M67 lies at an estimated distance of 2700 light years. The Equinox 2000 coordinates are RA= 8h 50.4m, Dec= +11° 49´ which makes M67 best seen during the winter. The Messier Winter Star Chart shows the position of all Messier objects visible during that season.
The image above shows the uncropped view of M67 through the Takahashi E-180 Astrograph (North is up). The bright star 1.1 degrees east of M67 is 60 Cancri (magnitude 5.44), while the star 1.1 degrees west is 50 Cancri (magnitude 5.88) A 3x enlargement of this image centered on M67 appears to the right.
In spite of its inclusion in the Messier Catalog, this open cluster was actually discovered by J. G. Koehler in 1779. M67 is one of the oldest open clusters known. It is estimated that it will exist as a cluster for another 5 billion years. According to Kharchenko et al. (2005), the distance of M67 is 2960 light years and its diameter is 21 light years. It contains 500 stars and its estimated age is 3.7 billion years.
Messier's Description of M67
April 6, 1780
`Cluster of small stars with nebulosity, below the southern claw of Cancer. The position determined from the star Alpha [Cancri].'
- Object: M67
- Other Names: NGC 2682
- Object Type: open cluster
- Object Data: Apparent Magnitude = 6.1, Angular Size = 30 arc-minutes
- Object Position (Equinox 2000): RA= 8h 50.4m, Dec= +11° 49´, Constellation = Cancer
- Date/Time: 2011 Mar 29 at 05:32 UTC
- Location: Bifrost Astronomical Observatory, Portal, AZ
- Mount: Astro-Physics 1200GTO
- Telescope: Takahashi Epsilon 180 Hyperbolic Astrograph
- Camera: Canon EOS 550D (Rebel T2i) (modified with a Baader UV/IR filter)
- Field of View: 1.70° x 2.56° at 1.7 arc-sec/pixel (web version: 10.0 arc-sec/pixel)
- Exposure: 2 x 300s, f/2.8, ISO 800
- File Name: M67-01w.jpg
- Processing (Adobe Camera Raw): Graduated Filter, Vignetting Correction, Noise Reduction, White Balance, Curves
- Processing (Photoshop CS5): Average Images, Curves, Noise Reduction
- Original Image Size: 3454 × 5179 pixels (17.9 MP); 11.5" x 17.3" @ 300 dpi
- Rights: Copyright 2011 by Fred Espenak. All Rights Reserved. See: Image Licensing.