ESO has conducted a survey of a number of globular clustrers using their new multi-spectrograph FLMAES, which is capable of analysing 130 targets in one session

We know of about 150 globular clusters that orbit our galaxy, the Milky Way. This sharp new image of Messier 107, displays the structure of one such globular cluster in exquisite detail. Studying these stellar swarms has revealed much about the history of our galaxy and how stars evolve.

The globular cluster Messier 107, also known as NGC 6171, is a compact and ancient family of stars that lies about 21 000 light-years away. Messier 107 is a bustling metropolis with thousands of stars in a compact space of only 80 light-years. A significant number of these stars have already evolved into red giants, one of the last stages of a star’s life, and have a yellowish colour in this image.

Globular clusters are among the oldest objects in the Universe. And since the stars within a globular cluster formed from the same cloud of interstellar matter at roughly the same time - typically over 10 billion years ago - they are all low-mass stars, as lightweights burn their hydrogen fuel supply much more slowly than larger stars. Globular clusters formed during the earliest stages in the formation of their host galaxies and therefore studying these objects can give significant insights into how galaxies, and their component stars, evolve.

Messier 107 has undergone intensive observations, being one of the 160 stellar fields that was selected for the Pre-FLAMES Survey. Using FLAMES, it is possible to observe up to 130 targets at the same time, making it particularly well suited to the spectroscopic study of densely populated stellar fields, such as globular clusters.

M107 is not visible to the naked eye, but, with an apparent magnitude of about eight, it can easily be observed from a dark site with binoculars or a small telescope in the constellation of Ophiuchus. The globular cluster is about 13 arcminutes across - only half the angular diameter of the full-Moon.

This image is composed from exposures taken through the blue, green and near-infrared filters by the Wide Field Camera (WFI) on the MPG/ESO 2,2m telescope at the La Silla Observatory in Chile.

Source: ESO