A new type of star is providing clues to the mysterious origin of magnetars which are the strongest magnets in the universe.
Magnetars are super-dense dead stars with ultra-strong magnetic fields and they can be found all over the Milky Way.
Astronomers don’t know exactly how they’re formed but using multiple telescopes around the world, including European Southern Observatory (ESO) facilities, researchers have uncovered a living star that is likely to become a magnetar.
The finding marks the discovery of a new type of astronomical object (massive magnetic helium stars) and sheds light on the origin of magnetars.
Even though the enigmatic nature of the star HD 45166 had been observed for more than 100 years, it could not be easily explained by conventional models.
Little was known about it beyond that it is one of a pair of stars, is rich in helium and is a few times more massive than the Sun.
Lead author, Tomer Shenar, an astronomer at the University of Amsterdam in the Netherlands, said the star had become a “bit of an obsession”.
Co-author and ESO astronomer Julia Bodensteiner, based in Germany, said: “Tomer and I refer to HD 45166 as the ‘zombie star’.
“This is not only because this star is so unique, but also because I jokingly said that it turns Tomer into a zombie.”
Magnetic fields are known to influence the behaviour of stars.
This could explain why traditional models failed to describe HD 45166 which is located about 3,000 light-years away in the constellation Monoceros.
The star has an incredibly strong magnetic field and is one of the most magnetic found to date, according to the study.
“The entire surface of the helium star is as magnetic as the strongest human-made magnets,” said co-author Pablo Marchant, an astronomer at KU Leuven’s Institute of Astronomy in Belgium.
The observation marks the discovery of the very first massive magnetic helium star, the scientists suggest.
Dr Shenar said: “It is exciting to uncover a new type of astronomical object, especially when it’s been hiding in plain sight all along.”
The findings, published in the Science journal, provide clues to the origin of magnetars, compact dead stars laced with magnetic fields at least a billion times stronger than the one in HD 45166.
The team’s calculations suggest this star will end its life as a magnetar.
As it collapses under its own gravity, its magnetic field will strengthen and the star will eventually become a very compact core and the most powerful type of magnet in the universe.
