V445 Puppis helium nova ejects 32 million km/h cosmic bullets

Astronomers using the Hubble Space Telescope have observed a pair of high‑speed gas knots, described as “cosmic bullets,” being expelled from V445 Puppis at about 32 million km per hour. V445 Puppis, the only known helium nova in the Milky Way, erupted in 2000 and is a rare binary system in which a white dwarf accretes helium‑rich material from a companion helium star.

The study, led by John Mills of the University of Warwick and combining observations from Hubble, NASA’s TESS mission and the Very Large Telescope, confirms the bullets are oxygen‑rich and their origin remains uncertain. Researchers note that understanding such eruptions could illuminate the pathways that lead to Type Ia supernovae, which serve as standard candles for measuring cosmic distances.