Central wavelengths of the first nine cyclotron harmonics (labeled 1 to 9) as a function of magnetic field (depicted by the black lines). The faded red and orange regions mark the ranges covered by the variable humps seen in STIS and COS, respectively. The dashed lines mark the centroid of each hump. For magnetic fields ranging from ≈400 − 600 MG (faded blue region), the positions of the two UV humps are consistent with the first and second cyclotron harmonics.