Messier 107 or M107 (also designated NGC 6171) is a globular cluster in the constellation Ophiuchus. It has an apparent visual magnitude of 7.9 and its angular diameter is 10 arc-minutes. M107 lies at an estimated distance of 20,900 light years. The Equinox 2000 coordinates are RA= 16h 32.5m, Dec= -13° 03´ which makes M107 best seen during the summer. The Messier Summer Star Chart shows the position of all Messier objects visible during that season.
The image above shows the uncropped view of M107 through the Takahashi E-180 Astrograph (North is up). A 3x enlargement of this image appears to the right.
This globular cluster was discovered by P. Méchain in 1781. According to Recio-Blanco et al.(2005), the distance of M107 is 27,370 light years and its diameter is 105 light years. Its estimated mass is 200,000 solar masses and it contains 23 variable stars.
Messier's Description of M107
Méchain in his letter to Bernoulli, May 6, 1783)
`In April 1782 I discovered a small nebula in the left flank of Ophiuchus between the stars Zeta and Phi, the position of which I have not yet observed any closer.'
- Object: M107
- Other Names: NGC 6171
- Object Type: globular cluster
- Object Data: Apparent Magnitude = 7.9, Angular Size = 10 arc-minutes
- Object Position (Equinox 2000): RA= 16h 32.5m, Dec= -13° 03´, Constellation = Ophiuchus
- Date/Time: 2011 Apr 11 at 10:32 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: M107-01w.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.