Hubble observes unique helium nova firing cosmic bullets through the Milky Way
Astronomers using the Hubble Space Telescope have found that the Milky Way’s only known helium nova is ejecting high‑speed particles that travel like cosmic bullets across the galaxy.
Observations reveal that the outburst gas reaches temperatures of several million degrees, with helium abundant. This triggers a thermonuclear burn of helium rather than the hydrogen fusion seen in typical novae.
The expelled particles attain speeds of about 20 million miles per hour, roughly 32 million kilometres per hour, placing them among the fastest free‑moving objects detected in our galaxy.
Such rapid outflows can stir interstellar material, affecting the chemical enrichment of the interstellar medium, and provide a natural laboratory to study processes akin to those in supernovae, albeit on a smaller scale.
Researchers say the discovery deepens our understanding of rare explosion types and helps plan future observations with other facilities to locate similar objects elsewhere.
- The helium nova is the sole known example of its kind in the Milky Way.
- Ejected particles move at roughly 20 million miles per hour.
- The data improve models of nucleosynthesis in helium‑rich explosive events.