RX J0720 evolution: precession comma glitching comma or the last flutterings of a magnetar

RX J0720 belongs to a group of seven radioquiet isolated neutron stars withsimilar properties. It is unique in that it shows long term variations in itsspectral parameters, like black body temperature, size of the emitting area andthe depth of the absorption feature. Furthermore, a phase coherent pulse timinganalysis assuming a constant spin period derivative shows large timingresiduals. The cause of this enigmatic behaviour is still a matter of debate:cyclic variations are expected if the neutron star precesses while a suddenevent like a glitch may cause a gradual evolution after a relatively fastchange. The recent results from our XMMNewton observations indicate that thetiming residuals follow an abs(sine) behaviour with the minimum expected around next year. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]