M16 - Eagle Nebula (NGC 6611)
The monochromatic image above shows M16 as shot through a Hydrogen Alpha filter.
Messier 16 or M16 (also designated NGC 6611) is a nebula and star cluster in the constellation Serpens. It has an apparent visual magnitude of 6.4 and its angular diameter is 7 arc-minutes. M16 lies at an estimated distance of 7000 light years. The Equinox 2000 coordinates are RA= 18h 18.8m, Dec= -13° 47´ which makes M16 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 Eagle Nebula.
In spite of its inclusion in the Messier Catalog, the star cluster portion of M16 was actually discovered by J-P. de Chéseaux in 1746. Messier did not notice the nebula but only recorded the star cluster. E. E. Barnard was probably the first to photograph the Eagle Nebula in 1895. It was designated as IC 4703 in 1908. The Eagle Nebula is a region of star formation. Its glowing hydrogen gas is due to excitation from ultraviolet radiation emitted by hot young stars embedded in the nebula. According to Kharchenko et al. (2005), the distance of M16 is 5600 light years and its diameter is 35 light years. It contains 376 stars and its estimated age is 2-6 million years.
For more information, see the Messier Catalog as well as specific entries for M16 in Wikipedia and SEDS.
Messier's Description of M16
June 3, 1764
`A cluster of small stars, enmeshed in a faint glow, near the tail of Serpens,
at little distance to the parallel of Zeta of this constellation; with an
inferior telescope this cluster appears like a nebula.'
(diam. 8')
Technical Details
- Object: M16 - Eagle Nebula
- Other Names: NGC 6611
- Object Type: nebula and star cluster
- Object Data: Apparent Magnitude = 6.4, Angular Size = 7 arc-minutes
- Object Position (Equinox 2000): RA= 18h 18.8m, Dec= -13° 47´, Constellation = Serpens Serpens
- Date: 2021 Jul 14-18,27-28, 30-31 (9 nights)
- Location: Chile Remote Observatory, Observatorio El Sauce, Chile
- Partnership: Operated in partnership with David Churchill
- Telescope: Planewave CDK-17 (with Focal Reducer: f/4.5; FL = 1945mm)
- Camera: QHY 16200A with Integral 7-position Filter Wheel
- Mount: Astro-Physics 1600GTO
- Guider: Agena Starguide II / SBIG STi
- Sub-Exposures: Astronomik Filters
- H-Alpha: 82 x 10 min = 820 min - Total Exposure: 13h 40m
- File Name: M16-CDK21Ha-C02w.jpg
- Field of View: 38.9' x 58.3' at 0.64 arc-sec/pixel
- Original Image Size: 3630 x 4540 pixels (16.5 MP); 12.1" x 15.1" @ 300 dpi
- Data Acquisition: David Churchill
- Image Processing: Fred Espenak
- Maxim DL: Image Calibration, Stacking, Log Stretch
- Adobe Camera Raw: Noise Reduction, Color/Contrast Adjustments
- Photoshop CC: Curves, Levels, Hi Pass Filter
- Topaz Labs: Sharpen AI - Copyright: Fred Espenak