Using spectropolarimetric data gathered by various telescopes around the globe, astronomers from the University of Amsterdam and elsewhere have identified a powerful magnetic field in the Wolf-Rayet star HD 45166, the exposed helium core of a star that has lost its outer layers of hydrogen. The mass of HD 45166 is high enough that it will produce a neutron star in a supernova, and the field is sufficiently strong to generate a magnetar during core collapse.
Neutron stars, the compact remains of a massive star following a supernova explosion, are the densest matter in the Universe.
Some neutron stars, known as magnetars, also claim the record for the strongest magnetic fields of any object.
How magnetars, which are a mere 15 km (9 miles) across, form and produce such colossal magnetic fields remains a mystery.
“For the first time, a strong magnetic field was discovered in a massive helium star,” said Dr. André-Nicolas Chené, an astronomer at NSF’s NOIRLab.
“Our study suggests that this helium star will end its life as a magnetar.”
HD 45166 is located approximately 3,000 light-years away in the constellation of Monoceros.
Also known as TIC 206762912 or TYC 732-754-1, the star is about two times the mass of the Sun, rich in helium, and is part of a binary system.
“This star became a bit of an obsession of mine,” said Dr. Tomer Shenar, an astronomer at the University of Amsterdam.
“Having studied similar helium-rich stars before, we were intrigued by the unusual characteristics of HD 45166, which has some of the characteristics of a Wolf-Rayet star, but with a unique spectral signature.”
“We suspected that magnetic fields could explain these perplexing characteristics.”
The astronomers tested their hypothesis by taking new spectropolarimetric observations of the HD 45166 system.
The observations revealed that the Wolf-Rayet star has a phenomenally powerful magnetic field, about 43,000 gauss, the most powerful magnetic field ever found in…
Read the full article here