Astronomers have found a new type of star that has a very strong magnetic field and is mostly made of helium, reports thedebrief.org.
The star is a rare variant of a Wolf-Rayet star, which are massive stars that lose their outer layers of hydrogen and helium in powerful winds.
The new star, named WR 142b, has a magnetic field of about 43,000 gauss, which is more than 10,000 times stronger than the Sun’s magnetic field. The star is also very hot, with a surface temperature of about 50,000 degrees Celsius.
The discovery of WR 142b was made by a team of researchers from the National Science Foundation’s NOIRLab, using data from several telescopes around the world, including the Canada-France-Hawai‘i Telescope (CFHT) on Maunakea.
The team used spectroscopy to measure the magnetic field of the star, which affects the way light is emitted or absorbed by its atoms. The team also estimated the mass and age of the star by studying its orbit around another star in a binary system.
The team believes that WR 142b is a very unusual and rare object, and that it could be a precursor to a magnetar, which is a type of neutron star with an extremely powerful magnetic field.
Neutron stars are the remnants of massive stars that explode as supernovae at the end of their lives. Magnetars are thought to have magnetic fields up to 1,000 trillion gauss, which are so strong that they can affect the structure of matter and space around them. However, the origin of magnetars is still unclear, and WR 142b could provide some clues.
“This is a very specific scenario, and it raises the question of how many magnetars come from similar systems and how many come from other types of systems,” said André-Nicolas Chené, a researcher at NOIRLab and one of the authors of the study. “Our study suggests that this helium star will end its life as a magnetar.”
The study was published in the journal Science on August 18, 2023.