Multiple, short-lived "stellar prominences" on the O giant $\xi$ Persei: a magnetic star?

N. Sudnik, H. F. Henrichs

We present strong evidence for a rotation period of 2.0406 d of the O giant $\xi$ Persei, derived from the NIV $\lambda$1718 wind line in 12 yr of IUE data. We predict that $\xi$ Per has a m…