Do dragons fight on the altar of the sky? Although it might appear that way, these dragons are
illusions made of thin gas and dust. The
emission nebula NGC 6188, home to the glowing clouds, is found about 4,000
light years away near the edge of a large molecular cloud unseen at visible wavelengths, in the southern
constellation Ara (the Altar). Massive, young
stars of the embedded Ara
OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense
ultraviolet radiation. The recent
star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive
stars, that swept up and compressed the molecular gas. Joining NGC 6188 on
this cosmic canvas, visible toward the lower right, is rare emission nebula NGC 6164, also created by one of the region's massive
O-type stars. Similar in appearance to many planetary nebulae, NGC 6164's striking, symmetric gaseous shroud and faint halo surround its bright central star near the bottom edge. This
impressively wide field of view spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance
of NGC 6188.