Panel a: Swift/BAT (black) and MAXI (green) fluxes in mCrab from March to May 2016 (left) and July to October 2016 (right). The fluxes were rescaled to the respective mCrab count-rates, using 0.00022 cts s^-1 cm^-2 (15–50 keV) for BAT and 0.0033 cts s^-1 cm^-2 (2–20 keV) for MAXI. Panel b: Flux measured in the 3–10 keV energy band in units of erg cm^-2 s^-1. For the data points shown as triangles the absorption was frozen to 5.9 × 10²² cm^-2 as it could not be constrained due to the low S/N. Furthermore, no pulsation search could be performed on those data for the same reason. The NuSTARflux is shown by a red square and the INTEGRAL/ISGRI flux is shown by a magenta circle and measured between 25–40 keV. The y-axis is scaled logarithmically. The right hand y-scale gives the implied spherical luminosities for a distance of d = 7.1 kpc. Panel c: Global absorption column N_H,1 measured with Swift/XRT in 10²² cm^-2. The columns of NuSTARand ISGRI were tied to the closest XRT point and are therefore not shown. Panel d: Pulse frequency ν−24.2 mHz in μHz. Blue crosses are values measured by Fermi/GBM, black diamonds are from Swift/XRT, and the red square is the NuSTARvalue. Panel e: Equivalent width of the Hα line, as measured in the NOT/ALFOSC spectra.