Messier 56

Messier 56
Messier 56 by Hubble Space Telescope. 3.6′ view Credit: NASA/STScI/WikiSky
Observation data (J2000 epoch)
Class	X
Constellation	Lyra
Right ascension	19h 16m 35.50s[1]
Declination	+30° 11′ 04.2″[1]
Distance	32.9 kly[2] (10.1 kpc)
Apparent magnitude (V)	+8.3
Apparent dimensions (V)	8′.8
Physical characteristics
Radius	42 ly[3]
Other designations	M56, NGC 6779, GCl 110[1]
See also: Globular cluster, List of globular clusters

Messier 56 with amateur telescope

Messier 56 (also known as M56 or NGC 6779) is a globular cluster in the constellation Lyra. It was discovered by Charles Messier in 1779. M56 is at a distance of about 32,900 light-years from Earth and measures roughly 84 light-years across.

The brightest stars in M56 are of 13th magnitude while it contains only about a dozen known variable stars, such as V6 (RV Tauri star; period: 90 days) or V1 (Cepheid: 1.510 days); other variable stars are V2 (irregular) and V3 (semiregular).

References

1. ^ ^{a b c} "SIMBAD Astronomical Database". Results for NGC 6779. http://simbad.u-strasbg.fr/Simbad. Retrieved 2006-11-16. 
2. ^ Valentin D. Ivanov, Jordanka Borissova, Almudena Alonso-Herrero, Tatiana Russeva (2000). "Near Infrared Photometry of Galactic Globular Clusters M56 and M15. Extending the Red Giant Branch vs. Metallicity Calibration Towards Metal Poor Systems". arXiv:astro-ph/0002118 [astro-ph]. 
3. ^ distance × sin( diameter_angle / 2 ) = 42 ly. radius

External links

• Messier 56, SEDS Messier pages
• Messier 56, Galactic Globular Clusters Database page
• Messier 56 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Coordinates: 19^h 16^m 35.50^s, +30° 11′ 04.2″