Astronomers have made an extraordinary discovery: they’ve detected a fleeting but incredibly bright explosion, leading them to uncover the first magnetic star outside our Milky Way. This magnetic star, known as a magnetar, was found in the galaxy M82, also known as the Cigar Galaxy, situated approximately 12 million light-years away from us. The discovery was made possible through observations using a telescope operated by the European Space Agency (ESA).
Magnetars are incredibly dense remnants of once-luminous stars, possessing exceptionally strong magnetic fields. These cosmic powerhouses are like rapidly spinning versions of neutron stars, the remnants of supernova explosions, but with magnetic fields thousands of times more intense than the sun’s. However, their eruptions are so brief and unpredictable that they pose a significant challenge for astronomers to study.
The detection of this extragalactic magnetar is particularly significant because it opens up the possibility of finding more such magnetic stars beyond our galaxy. Only a handful of magnetar flares have been recorded in the past half-century, making this discovery a notable milestone in astrophysics.
The journey to this discovery began in mid-November 2023 when ESA’s Integral space telescope detected a sudden burst of gamma rays emanating from the direction of M82. Further observations confirmed that this burst originated from a magnetar within the galaxy rather than from other cosmic phenomena like black hole births or neutron star mergers.
Follow-up observations with ground- and space-based telescopes confirmed the presence of a magnetar in M82. The absence of expected afterglow and gravitational waves associated with typical gamma-ray bursts provided strong evidence supporting the magnetar hypothesis.
This newfound extragalactic magnetar joins the ranks of three others previously discovered within our own galaxy. While one of these magnetars, spotted in 2004, caused disruptions to spacecraft due to its proximity to Earth, the newly discovered magnetar in M82 is far too distant to pose any such threat.
This breakthrough not only expands our understanding of magnetars but also paves the way for further exploration into the mysterious and captivating realm of extragalactic astrophysics.
