Detection of nearly periodic spin period reversals in Vela X-1 on long time-scales: inkling of solar-like cycle in the donor star?

Amar Deo Chandra, Jayashree Roy, P. C. Agrawal +1

We explore the long-term evolution of the spin period of the High Mass X-ray Binary (HMXB) pulsar Vela X-1 over a period of 46 yr. Our analysis indicates nearly periodic variations…