Messier 93 or M93 (also designated NGC 2447) is an open cluster in the constellation Puppis. It has an apparent visual magnitude of 6 and its angular diameter is 22 arc-minutes. M93 lies at an estimated distance of 3600 light years. The Equinox 2000 coordinates are RA= 7h 44.6m, Dec= -23° 52´ which makes M93 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 M93 through the Takahashi E-180 Astrograph (North is up). A 3x enlargement of this image appears to the right.
This small, bright open cluster was discovered by Messier in 1781. According to Kharchenko et al. (2005), the distance of M93 is 3380 light years and its diameter is 23 light years. It contains about 80 stars and its estimated age is 400 million years.
Messier's Description of M93
March 20, 1781
`Cluster of small stars, without nebulosity, between the Greater Dog [Canis Major] and the prow of the ship [Puppis of Argo Navis].' (diam 8')
- Object: M93
- Other Names: NGC 2447
- Object Type: open cluster
- Object Data: Apparent Magnitude = 6, Angular Size = 22 arc-minutes
- Object Position (Equinox 2000): RA= 7h 44.6m, Dec= -23° 52´, Constellation = Puppis
- Date/Time: 2011 Apr 01 at 04:09 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: M93-01w.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.