An ultrabright explosion has led astronomers to find the first magnetic star to be discovered outside the Milky Way — and there could be many more out there.
The newfound magnetar, a dense relic of a once-bright star with a remarkably strong magnetic field, resides in the galaxy M82 (dubbed the Cigar Galaxy), roughly 12 million light-years from Earth.
However, their eruptions are so fleeting and unpredictable that they are tricky targets for astrophysicists to study.
Only three other magnetar flares have been recorded in the past 50 years, so the latest find opens the search for more extragalactic magnetars, scientists say.
Related: Bizarre new cosmic object is the most magnetic star in the universe A star that had a blast In mid-November 2023, ESA’s Integral space telescope flagged a brief, sudden flare of gamma-rays in the direction of M82.
Similar radiation also blasts out during the births of black holes, mergers of orbiting neutron stars, and other exotic phenomena unrelated to magnetars.
“Gamma-ray bursts come from far away and anywhere in the sky, but this burst came from a bright nearby galaxy.”
Follow-up observations of the burst with ground- and space-based telescopes a few hours later localized its position within M82.
Astronomers have found the first magnetic star outside of the Milky Way thanks to an incredibly bright explosion, and there may be many more out there.
The newly discovered magnetar is located in the galaxy M82, also known as the Cigar Galaxy, about 12 million light-years from Earth. It is a dense remnant of a once-bright star with an exceptionally strong magnetic field. A new study published in the journal Nature on Wednesday, April 24, states that the ultramagnetic star was discovered by scientists using an European Space Agency (ESA) telescope after it violently erupted and blasted out intense energy that lasted only a fraction of a second.
Magnetars are rapidly spinning, highly magnetized neutron star remnants from supernova explosions that shine thousands of times brighter than the sun. They are sometimes referred to as the universe’s most powerful magnets. However, astrophysicists find it difficult to study these objects because of how erratic and transient their eruptions are. As there have only been three other magnetar flares discovered in the previous 50 years, researchers say that the most recent discovery expands the search for more extragalactic magnetars.
“We can begin to comprehend the frequency of these flares and the energy loss that these stars undergo,” said Ashley Chrimes, an ESA researcher who was not directly involved in the recent study, in a statement. “If we can find many more.”.
Related: The universe’s most magnetic star is a strange new cosmic object.
An incredibly fun star.
An abrupt and brief gamma-ray flare was detected in the direction of M82 by ESA’s Integral space telescope in mid-November 2023. A similar amount of radiation is also released during the formation of black holes, the merger of orbiting neutron stars, and other unusual events unrelated to magnetars.
“We knew right away that this was a special alert,” the statement from the study’s lead author, Sandro Mereghetti, an Italian researcher at the National Institute for Astrophysics, said. “This burst originated in a bright nearby galaxy, but Gamma-ray bursts can originate from anywhere in the sky, even at great distances. “.
A few hours later, additional observations of the burst using space and ground-based telescopes pinpointed its location within M82. Astronomers observed only hot gas and stars, which proved that the flare originated from a magnetar, as opposed to the fading afterglow and gravitational waves that would be expected from a typical gamma-ray burst, the study said.
The detected flare can be explained by the so-called “starquake,” which occurs when a magnetar’s strong magnetic fields ever-so-slightly disrupt the star’s outer layers and break the star’s spin. This causes the star’s surface to crack and emit highly energetic gamma-rays into space.
The project scientist for ESA’s Integral mission, Jan-Uwe Ness, stated in the statement that “we would not have such strong proof that this was indeed a magnetar and not a gamma-ray burst if the [follow-up] observations had been performed even just a day later.”.
