NICER observation list: Target ID 251501

Magnetar emission is powered by the instability and/or decay of their huge magnetic fields. They emit outbursts, where the X-ray luminosity rises up to 3 orders of magnitude, and subsequently decays back to the quiescent value on different timescales. The mechanism responsible for the activation and the long-term evolution of these outbursts is still poorly understood. We propose a timing campaign of the magnetar 1E 1547-5408 to assess its current rotational properties while recovering from its last major outburst about a decade ago, and test the theoretical models proposed to explain magnetar outbursts. The proposed observations will be crucial to understand the driver of the prolonged, sustained emission of this source and, ultimately, the physical mechanisms behind magnetar outbursts.