The G+M eclipsing binary V530 Orionis photometry

On the other hand, models from the Dartmouth series incorporating magnetic fields are able to match the observations of the secondary star at the same age as the primary (~3 Gyr) with a surface field strength of 2.1+/-0.4 kG when using a rotational dynamo prescription, or 1.3+/-0.4 kG with a turbulent dynamo approach, not far from our empirical estimate for this star of 0.83+/-0.65 kG. The observations are most consistent with magnetic fields playing only a small role in changing the global properties of the primary.

The V530 Ori system thus provides an important demonstration that recent advances in modeling appear to be on the right track to explain the long-standing problem of radius inflation and temperature suppression in low-mass stars.