GLOBULAR CLUSTER IN OPHIUCHUS
(Image Centred at ra 16h:57.1m / dec -04:06)
CLICK IN THE IMAGE FOR A HIGH RESOLUTION VIEW
May 2014 - Camping La Porteņa, San Antonio de Areco, Buenos Aires, Argentina
Type: Globular Cluster
Apparent magnitude: 6.6
Apparent diameter: 15.1 arc minutes
Distance: 14.400 light years
SCOPE: 8" Orion Optics UK with Televue Paracorr
CAMERA: QSI 583 WS
FILTERS: Baader LRGB
SKY CONDITIONS: rural skies, foggy night
EXPOSURES: LRGB (60,30,30,30)
OBJECT DESCRIPTION AND IMAGE SESSION
One of the brightest globular clusters in the equatorial constellation of Ophiuchus. It appears at about 7 to 8 arc minutes of diameter when observed visually in smaller instruments. Average photographs show 15 arc minutes in diameter. The clusters spans in an area of 83 light years.
It was discovered in 1764 and like most globular cluster Charles Messier described as a "nebula without stars". William Herschel was the first to resolve the object into stars. He described it as a "beautiful cluster of extremely compressed stars"