Messier 41 or M41 (also designated NGC 2287) is an open cluster in the constellation Canis Major. It has an apparent visual magnitude of 4.6 and its angular diameter is 38 arc-minutes. M41 lies at an estimated distance of 2300 light years. The Equinox 2000 coordinates are RA= 6h 47m, Dec= -20° 44´ which makes M41 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 M41 through the Takahashi E-180 Astrograph (North is up). A 2x enlargement of this image appears to the right.
In spite of its inclusion in the Messier Catalog, this open cluster was actually discovered by G. B. Hodierna in 1654. M41 lies 4 degrees south of Sirius. According to Kharchenko et al. (2005), the distance of M41 is 2260 light years and its diameter is 26 light years. It contains 70 stars and its estimated age is 190 million years.
Messier's Description of M41
January 16, 1765
`Cluster of stars below Sirius, near Rho Canis Majoris; this cluster appears nebulous in an simple refractor of one foot; it is nothing more than a cluster of small stars.'
- Object: M41
- Other Names: NGC 2287
- Object Type: open cluster
- Object Data: Apparent Magnitude = 4.6, Angular Size = 38 arc-minutes
- Object Position (Equinox 2000): RA= 6h 47m, Dec= -20° 44´, Constellation = Canis Major
- Date/Time: 2011 Mar 29 at 03:00 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: M41-01w.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.