Asymmetric supernovae: not all stellar explosions expand spherically

Stars are balls of glowing gas, with a nearly spherical shape. Accordingly, one would expect that when some stars explode as supernovae at the end of their lives, the resulting colossal fireballs should share this spherical symmetry. However, recent investigations are revealing that some of these events are not round. New data gathered at Calar Alto Observatory reinforce this surprising finding.