Fr.: V2052 Oph
A hot star of → apparent visual magnitude V = 5.82 lying in the constellation → Ophiuchus, also known as HR 6684, HD 163472, and HIP 87812. V2052 Oph is of → subgiant → spectral type B2 IV-V and belongs to the family of magnetic → Beta Cephei → pulsators. It has a luminosity of 620 Lsol, a radius of 6.83 Rsol and lies about 830 → light-years away. Three stellar pulsation modes have been detected and studied from ground-based spectroscopy and multi-color photometry. Its magnetic field was deduced to be → dipolar dipolar with a strength of ~ 400 G, inclined 35° to the rotation axis. The star's → convective overshooting region is small, with no extra mixing in spite of the relatively large rotational velocity. This clearly illustrated the effect of the magnetic field: the inhibition of chemical mixing processes by the magnetic field. This result is in agreement with theoretical criteria, which predict that a surface magnetic field of ~ 70 G is sufficient to limit the overshooting in this star. V2052 Oph is now considered as a prime example of what magneto-asteroseismology can achieve (Neiner et al., 2012, A&A, 537, A148).