NASA Fermi Confirms Gamma Rays From SN 2017egm, a Supernova 440 Million Light-Years Away
Updated
Updated · Space.com · May 25
NASA Fermi Confirms Gamma Rays From SN 2017egm, a Supernova 440 Million Light-Years Away
1 articles · Updated · Space.com · May 25
SN 2017egm is the first supernova to show definitive gamma-ray emission in nearly 20 years of Fermi searches, based on results published May 20 in Astronomy & Astrophysics.
Modeling tied the signal to a newborn magnetar formed in the core collapse, whose wind of electrons and positrons can generate gamma rays that begin leaking out about three months after the blast.
The same mechanism may explain why superluminous supernovas shine more than 10 times brighter in visible light than typical core-collapse explosions, as gamma rays are reprocessed by the expanding debris shell.
Among the six nearest superluminous supernovas examined in Fermi's first 16 years, only SN 2017egm—about 440 million light-years away in NGC 3191—showed the signal.
Researchers said the upcoming Cerenkov Telescope Array Observatory should detect similar events out to roughly 500 million light-years in 50 hours, opening a new way to probe supernova interiors.
With magnetars confirmed as the engine, what other secrets of Einstein's relativity can these extreme cosmic laboratories now reveal?
How does observing a wobbling spacetime around a magnetar change our understanding of the universe's most powerful explosions?
Fermi Telescope’s Historic Gamma-Ray Discovery in SN 2017egm Validates Magnetar Model for Superluminous Supernovae
Overview
NASA's Fermi Gamma-ray Space Telescope made a groundbreaking discovery by detecting gamma rays from the superluminous supernova SN 2017egm. This is the first time such high-energy signals have been observed from a superluminous supernova, marking a pivotal moment in astrophysics. The detection opens a new window into the complex physics of these extremely bright explosions. It provides crucial evidence supporting the magnetar hypothesis, which suggests that the intense luminosity of superluminous supernovae is powered by a newly formed neutron star with an exceptionally strong magnetic field, known as a magnetar.