Messier 48 or M48 (also designated NGC 2548) is an open cluster in the constellation Hydra. It has an apparent visual magnitude of 5.5 and its angular diameter is 54 arc-minutes. M48 lies at an estimated distance of 1500 light years. The Equinox 2000 coordinates are RA= 8h 13.8m, Dec= -05° 48´ which makes M48 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 M48 through the Takahashi E-180 Astrograph (North is up). A 2x enlargement of this image appears to the right.
This open cluster was discovered by Messier in 1771. Under favorable conditions it is visible to the naked eye as a fuzzy patch. According to Kharchenko et al. (2005), the distance of M48 is 2510 light years and its diameter is 22 light years. It contains 165 stars and its estimated age is 300 million years.
Messier's Description of M48
February 19, 1771
`Cluster of very small [faint] stars, without nebulosity; this cluster is at a short distance from the three stars that form the beginning of the Unicorn's tail.'
- Object: M48
- Other Names: NGC 2548
- Object Type: open cluster
- Object Data: Apparent Magnitude = 5.5, Angular Size = 54 arc-minutes
- Object Position (Equinox 2000): RA= 8h 13.8m, Dec= -05° 48´, Constellation = Hydra
- Date/Time: 2011 Apr 01 at 04:22 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: M48-01w.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.