Star cluster NGC 6193 is in the center of this image. It contains thirty or so bright stars and forms the heart of the Ara OB1 association (so named because it is in the southern constellation of Ara, the Altar). The two brightest stars are very hot giants. Together, they provide the main source of illumination for the nearby emission nebula, the Rim Nebula, or NGC 6188, visible to the right of the cluster.
The ultraviolet radiation and intense stellar wind from the stars of NGC 6193 seem to be driving the next generation of star formation in the surrounding clouds of gas and dust. As the gas and duct collapse, it forms new stars.
Image Credit: ESO