MESSIER 10

GLOBULAR CLUSTER IN OPHIUCHUS  

 (Image Centred at ra 16h:57.1m / dec -04:06)

May 2014 - Camping La Porteña, San Antonio de Areco, Buenos Aires, Argentina

DATA

Type: Globular Cluster

Apparent magnitude: 6.6

Apparent diameter: 15.1 arc minutes

Distance: 14.400 light years

IMAGE INFORMATION

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"