Astronomers have made a groundbreaking discovery outside the Milky Way: the first magnetic star found beyond our galaxy. This newly spotted magnetar, a dense remnant of a once-bright star with an incredibly strong magnetic field, exists in the galaxy M82, also known as the Cigar Galaxy, located approximately 12 million light-years from Earth. European Space Agency (ESA) scientists detected this ultramagnetic star after it experienced a powerful explosion releasing intense energy in a fraction of a second.
Magnetars, often referred to as the universe’s most powerful magnets, are rapidly spinning neutron stars that are intensely magnetized remnants of supernova explosions. These star remnants shine thousands of times brighter than the sun, making them intriguing yet challenging subjects for astrophysicists to study due to their unpredictable and fleeting eruptions. With only three other recorded magnetar flares in the past 50 years, the recent discovery in M82 opens up possibilities for uncovering more extragalactic magnetars, providing valuable insights into their frequency and energy loss mechanisms.
The discovery of this magnetic star originated from an ultrabright explosion that caught the attention of astronomers in mid-November 2023 when ESA’s Integral space telescope detected a sudden gamma-ray flare in the direction of M82. Further observations using ground and space-based telescopes pinpointed the flare’s location within the galaxy, revealing hot gas and stars instead of the expected gravitational waves associated with common gamma-ray bursts. This confirmation led researchers to identify the flare as coming from a magnetar, shedding light on the unique phenomena exhibited by these powerful celestial bodies.
The event, known as a starquake, occurred when the intense magnetic fields of the magnetar caused a slight disruption in its spin, leading to the cracking of its surface and the emission of highly energetic gamma-rays throughout the universe. Follow-up investigations conducted just hours after the initial detection provided crucial evidence supporting the magnetar origin of the flare, showcasing the significance of timely observations in astrophysical research.
By expanding the search for magnetars beyond our galaxy, scientists hope to gain a better understanding of these enigmatic stars’ characteristics and behavior. This recent breakthrough adds to the small number of known magnetars within our own Milky Way, offering a unique opportunity to explore the mysteries of these cosmic powerhouses. As researchers delve deeper into the realm of magnetars, they aim to unravel the mechanisms behind their eruptions and the ways in which these extraordinary stars interact with their surroundings, furthering our knowledge of the intricate dynamics of the universe.