LAUSR

It is generally believed that the first stars were hot and massive because of the lack of efficient coolants in the metal-free primordial gas. This paper considers the thermal generation of the magnetic field in such stars. The mechanism operates in the surface layers of hot stars where departures from the local thermodynamic equilibrium form a region with the inverse temperature gradient (it occurs in atmospheric layers with the optical depth ≤0.01–0.001). The thermal generation is efficient in stars with a low mass-loss rate. A growth rate of the magnetic field can be such high that even young stars with the age ∼104–105 yr possess the magnetic field comparable to that detected in massive stars of the present-day Universe.