Hubble telescope watches unique nova explosion fire cosmic 'bullets' through the Milky Way at 20 million mph

Astronomers using the Hubble Space Telescope have identified a rare cosmic event occurring within our galaxy. The object V445 Puppis, known as the only helium nova in the Milky Way, is ejecting matter at speeds reaching 20 million miles per hour. Researchers describe these high-velocity emissions as cosmic bullets, a phenomenon never documented in other nova systems.

This specific stellar system consists of a dead star, a white dwarf, drawing material from a rare helium-rich companion star. For over two decades, a dense cloud of dust obscured the system following a 2000 eruption. Recent observations from the Very Large Telescope and the TESS spacecraft allowed the research team to finally clear the mystery surrounding the nature of these stars.

The findings offer insight into how white dwarfs feed on their neighbors. Because the white dwarf in V445 Puppis is currently consuming more matter from its partner, experts believe a repeat eruption is possible. This process is important because scientists suspect such repeated helium nova events might eventually trigger a Type Ia supernova.

Type Ia supernovas serve as standard candles in astronomy. Because their light output is predictable, they help researchers measure cosmic distances and calculate the expansion rate of the universe. Studying V445 Puppis provides a window into the mechanics of these powerful explosions and the role they play in the larger structure of space.

The research was recently presented at the Royal Astronomical Society's National Astronomy Meeting in Birmingham. Scientists continue to monitor the system to determine if a second explosion will occur as predicted.