Free Astronomy Magazine September-October 2025

8 ASTRO PUBLISHING turies-old remains of supernova SNR 0509-67.5 with the European South- ern Observatory’s Very Large Tele- scope (ESO’s VLT), they have found patterns that confirm its star suffered a pair of ex- plosive blasts. This discovery shows some of the most im- portant explosions in the Uni- verse in a new light. Most supernovae are the explo- sive deaths of massive stars, but one important variety comes from an unassuming source. White dwarfs, the small, inactive cores left over after stars like our Sun burn out their nuclear fuel, can produce what astronomers call a Type Ia supernova. “The explosions of white dwarfs play a crucial role in astronomy,” says Priyam Das, a PhD student at the University of New South Wales Canberra, Australia, who led the study on SNR 0509-67.5 published in Nature Astronomy . Much of our knowledge of how the Universe expands rests on Type Ia su- pernovae, and they are also the pri- mary source of iron on our planet, including the iron in our blood. “Yet, despite their importance, the long-standing puzzle of the exact mechanism triggering their explo- sion remains unsolved,” he adds. SEPTEMBER-OCTOBER 2025 F or the first time, astronomers have obtained visual evidence that a star met its end by deto- nating twice. By studying the cen- A star met its end by detonating twice by ESO Bárbara Ferreira T his image marks the position on the sky of the supernova remnant SNR 0509- 67.5, the expanding shells of a star that detonated twice. It is located 160,000 light-years away in the Large Magellanic Cloud, a small galaxy orbiting our own Milky Way. The inset shows new observations with ESO’s Very Large Telescope (VLT), which show that the original star died with two explosive blasts. The main image shows the VLT unit telescope used in these observations. [ESO/Inset: P. Das et al., background stars (Hubble): K. Noll et al.]