Overview
- A paper published in Astronomy & Astrophysics in May 2026 reports that NASA’s Fermi Large Area Telescope found convincing GeV gamma‑ray emission tied to SN 2017egm.
- SN 2017egm, which was discovered by ESA’s Gaia on May 23, 2017, exploded in galaxy NGC 3191 about 440 million light‑years away and is one of the nearest known superluminous supernovae.
- Modeling of the gamma‑ray and optical data shows a newly born, rapidly rotating magnetar can reproduce the early high luminosity and the timing of the gamma rays.
- The magnetar model does not fully explain irregular fading seen at late optical times, so the team proposes additional processes such as fallback accretion or interaction with earlier stellar ejecta.
- Researchers say the result is based on a single clear case and urge coordinated multiwavelength campaigns and targeted observations with next‑generation ground arrays like CTA, which could detect similar events out to roughly 500 million light‑years with about 50 hours of exposure.