Determine whether other apparently non-magnetic O stars host corotating dipolar fields

Determine whether O-type stars without detected magnetic fields can nevertheless host stable corotating dipolar magnetic fields that produce rotationally modulated wind variability.

Background

The paper applies comparable period-search techniques to IUE spectra of 68 Cyg, ζ Pup, and λ Cep but finds no significant periodicity near their estimated rotation periods. Because those datasets have fewer spectra, lower signal-to-noise ratios, or poorer temporal coverage than the ξ Per data, the non-detections do not resolve whether similar weak magnetic fields exist in other O stars.

References

So the question whether other O stars without a detected magnetic field may still host a corotating dipolar field can therefore not be answered at this stage.

— Rotation period of the O giant xi Persei: Coexistence of cyclic and periodic variability. A weakly magnetic candidate star  (2610.12323 - Henrichs et al., 8 Oct 2026) in Section 9, “Period search in other O stars”

Highly sensitive magnetic measurements in the future might eventually prove or disprove our conjecture that ξ Per hosts a magnetic field, while shedding light on how the magnetic surface properties interact with the photospheric drivers of the DACs.

— Rotation period of the O giant xi Persei: Coexistence of cyclic and periodic variability. A weakly magnetic candidate star  (2610.12323 - Henrichs et al., 8 Oct 2026) in Section 10, “Conclusions”