M11 - Wild Duck Cluster
Messier 11 or M11 (also designated NGC 6705) is an open cluster in the constellation Scutum. It has an apparent visual magnitude of 6.3 and its angular diameter is 14 arc-minutes. M11 lies at an estimated distance of 6000 light years. The Equinox 2000 coordinates are RA= 18h 51.1m, Dec= -06° 16´ which makes M11 best seen during the summer. The Messier Summer Star Chart shows the position of all Messier objects visible during that season. As one of the more famous objects in the Messier Catalog, it is commonly known as the Wild Duck Cluster.
The image above shows the uncropped view of M11 through the Takahashi E-180 Astrograph (North is to right). A 3x 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. Kirch in 1681. The Wild Duck Cluster is one of the richest and most compact open clusters known. According to Kharchenko et al. (2005), the distance of M11 is 6120 light years and its diameter is 23 light years. It contains 2900 stars and its estimated age is 250 million years.
For more information, see the Messier Catalog as well as specific entries for M11 in Wikipedia and SEDS.
Messier's Description of M11
May 30, 1764
`Cluster of a great number of small [faint] stars, near the star K of Antinous [ Sct], which one can see only in a good instrument; with an simple refractor of 3 feet it resembles a Comet: This cluster is mingled with a faint glow; in this cluster there is a star of 8th magnitude. M. Kirch observed it in 1681. Philosophical Transactions No. 347, p. 390. It is reported on the English Atlas Coelestis.' (diam. 4')
Technical Details
- Object: M11
- Other Names: NGC 6705, Wild Duck Cluster
- Object Type: open cluster
- Object Data: Apparent Magnitude = 6.3, Angular Size = 14 arc-minutes
- Object Position (Equinox 2000): RA= 18h 51.1m, Dec= -06° 16´, Constellation = Scutum
- Date/Time: 2011 Oct 20 at 03:05 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: 8 x 300s, f/2.8, ISO 800
- File Name: M11-01w.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.