Ever heard the term ‘champagne flow?’ I’m not talking about a celebration, it’s actually a term in astronomy.  When a cluster of massive stars form and ionize the surrounding hydrogen cloud, the hot gas propels itself through the layers of cooler gas at the cluster outskirts.  When the hot gas finally bursts through to the vacuum of space, it flows rapidly like a newly opened bottle of champagne.  This is exactly what’s happening in the cluster RCW 34, a young, gaseous cluster in the southern constellation Vela. The interesting thing about this cluster is that its nearly invisible in optical...