Newly discovered magnetar is traversing our galaxy from an unknown place

Magnetars are neutron stars with immense magnetic fields, a trillion times stronger than Earth’s. SGR 0501+4516, one of the roughly 30 known magnetars in the Milky Way, was discovered in 2008 after NASA’s Swift Observatory detected gamma-ray flashes at the galaxy’s edge. Unlike typical magnetars, which are believed to form from supernova explosions, SGR 0501+4516 may have a different origin.

Its proximity to the supernova remnant HB9 once suggested a supernova birth. However, with only 80 arcminutes separating them—about the width of a pinky finger at arm’s length—its true origin remains a mystery. This unique magnetar might even offer clues to the enigmatic fast radio bursts observed in the universe.



A decade-long study using Hubble has questioned the link between magnetar SGR 0501+4516 and the nearby supernova remnant HB9. Researchers tracked the magnetar’s faint infrared glow in 2010, 2012, and 2020, and by aligning Hubble’s observations with Gaia’s stellar map, they confirmed that its motion rules out any connection to HB9. Tracing its trajectory also showed no ties to other supernova remnants or massive star clusters.

This raises new possibilities about the magnetar’s origin. It might be older than its estimated 20,000 years or could have formed through other processes. Potential origins include the merger of two smaller neutron stars or accretion-induced collapse, where a white dwarf in a binary system gains enough gas from its companion to trigger a collapse into a neutron star.

Newly discovered magnetar emits regular pulses of light Usually, a white dwarf in a binary system explodes after triggering nuclear reactions, leaving no remains. However, researchers believe that under certain conditions, it may instead collapse into a neutron star, possibly explaining the magnetar SGR 0501+4516’s origin. SGR 0501+4516 is the best candidate for a magnetar formed through merger or accretion-induced collapse in our galaxy.

This process may also explain fast radio bursts, often from older star populations without recent supernova activity. Studying magnetar birth and formation is vital for understanding powerful cosmic events like gamma-ray bursts, super-luminous supernovae, and fast radio bursts. Journal Reference: A.

A Chrimes, A. Levan et al. The infrared counterpart and proper motion of magnetar SGR 0501+4516.

Astronomy & Astrophysics. DOI: 10.1051/0004-6361/202453479 Topics Galaxy Magnetar Milky way Neutron star Supernova.