MESSIER 12

GLOBULAR CLUSTER IN OPHIUCHUS

 (Image Centred at ra 16h:47m / dec -01:57)

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

DATA

Type: Globular Cluster

Apparent magnitude: 6.6

Apparent diameter: 14.5 arc minutes

Distance: 15.700 light years

IMAGE INFORMATION

SCOPE: 8" Orion Optics UK Mirror with Televue Paracorr (1150 mm focal length)

CAMERA: QSI 583 WS

FILTERS: Baader LRGB

SKY CONDITIONS: rural skies, foggy night

EXPOSURES: LRGB (30,30,30,30)

OBJECT DESCRIPTION AND IMAGE SESSION

Messier 12 is one of the original Charles Messier discoveries. It was found in May the 30th of 1764. Like many other globular clusters he described it as a "nebula without stars". William Herschel was the first to resolve it into stars in 1783. A study published in 2006 concluded that this cluster has a unusually low number of low mass stars. Such stars where stripped out from the cluster by the gravitational influence of our Milky Way.

A pair of far away galaxies can be noted in the upper limit of the cluster which are only seen from our perspective. Messier 12 can be observed from dark skies with binoculars. In order to resolve its stellar components it requires telescopes with 8 inches of aperture or grater. Messier 12 is apparently very similar with Messier 10. It can be easily found 2 degrees north and 2 degrees west of M10 or 2 degrees North and 8.5 degrees East from Delta Ophiuchi.