Constelation of Sagitarius, distant from 19,000 light years. ESO discovered a microlensing by a black hole with a mass twice of the Sun. Maybe it lies inside the cluster. It brings out an amplified image of a red giant star of the background object.
I didn't understand who the ESO's arrow is pointing exactly: the stars near its tip or the red star near and on its direction.
http://www.eso.org/public/images/potw1540a/
http://www.eso.org/public/archives/r.../potw1540a.pdf
GSO 305 mm - Canon T3 - 24 x 2 min (48 min) - OAG - Skyglow filter - Coma corrector
http://www.astrobin.com/218916/
Some images are larger than 200 Kb, therefore only by link:
http://jsmastronomy.30143.n7.nabble....ter-td480.html