HD_45166
HD 45166
Star in the constellation Monoceros
HD 45166 is a binary consisting of a so-called quasi Wolf–Rayet (qWR) star and a B-type main-sequence star, near the cluster NGC 2244, in the constellation of Monoceros.[5] A quasi Wolf–Rayet star is a star with a spectrum resembling those of true Wolf–Rayet stars, but being less massive and luminous than a true Wolf–Rayet star. The primary of HD 45166 is currently the only known example of a qWR star.
In 2023, the primary of HD 45166 was also found to be extremely magnetic, the most magnetic massive star known. It is currently the only Wolf-Rayet star in which a significant magnetic field was measured. It has a magnetic field strength of up to 43 kG, or about 43,000 times the Sun's magnetic field strength. This means that it is likely that when it dies in a type Ib/IIb supernova, the remnant will be a magnetar.[3]