Many red supergiant monster stars lurk in a Milky Way cluster astronomers have discovered with the Gaia space telescope. The cluster, Barbá 2, could help understand why some stars become black holes.

In mid-February around 8 p.m., the majestic constellation Orion is due south, with his three-star belt and bright white foot (the star Rigel) and bright red-orange shoulder (the star Betelgeuse). L… ...