A Detailed Analysis Of Psr J2021+4026, The First Variable Gamma-Ray Pulsar

We present a novel Fermi-LAT analysis of PSR J2021+4026, the first variable.-ray pulsar. With a maximum likelihood fit, we measure variations in the.-ray flux and spectral parameters of the source on different timescales. We study the evolution of the rotational parameters and test a simple model that relates spin-down variations to jumps in the.-ray flux. This preliminary work underlines the importance of the variability analysis to understand pulsar magnetospheres.