Astronomers from the collaboration MOBSTER opened a new magnetic massive star. These objects are quite rare and have a strong surface magnetic field, origin and evolution of which is difficult to describe. It is noteworthy that the main role in the opening of the played data of the space telescope TESS, who is usually engaged in the search for exoplanets. Preprint published on the portal arXiv.org.
Spectropolarimetric surveys of the sky showthat there exists a population of massive magnetic stars of spectral classes O, B and A, which have recorded strong surface magnetic field. A key feature of these stars is the lack of correlation between the parameters of the star and its magnetic properties. In contrast to magnetic fields of low-mass stars, which have a complex topology of magnetic field and activity cycles associated with the magnetic field of massive stars is topologically simple (mostly dipole), have a greater field strength and stable for decades. Still there are arguments about the mechanism of formation of these magnetic fields and their evolution. The situation is complicated by the small number of observations — is known today only 11 stars magnetic O-type and less than one hundred magnetic stars early B-type.
A group of researchers from the collaboration MOBSTER (Magnetic OB[A] Stars with TESS: probing their
Evolutionary and Rotational properties), headed by Alexandre David-Uraz (Alexandre David-Uraz) from the University of Delaware announces the discovery of a new magnetic star-type HD 38170. The discovery was made while analyzing the data of the space telescope TESS, that resulted seven candidate found in magnetic stars. The subsequent study of candidates with the help of telescope CFHT (Canada-France-Hawaii Telescope) has allowed to establish that one of the stars is indeed magnetic.
HD 38170 refers to the variable stars of type α2 Beagle Dogs, has a radius of about 3.3 radii of the Sun, a mass of about 2.8 solar masses and the period of rotation of about 1,38 earth day. The effective temperature of stars is estimated at 10300 Kelvin, and its age — 394 in a million years. The maximum measured longitudinal field induction was 105 degrees, for comparison, the average field strength of the Sun in the level of the photosphere is estimated to be several Gauss. The researchers note that additional monitoring and modeling to fully describe the magnetic field of this star, and already the results show how useful data photometric telescope TESS to search for candidates in a magnetic star.
Earlier we talked about how astrophysicists have learned to measure the magnetic field inside the red giants, as the weakening of the magnetic field provided rapid rotation of old stars, and why physicists have questioned the nature of the magnetic field of the Sun.