The internight variability of the optical to near-infrared flux density and polarization of the blazars 0215+015 and 0851+202 during outbursts
We show that the internight variability of flux density and polarization at optical and near-infrared wavelengths (0.36-2.2 μm) of the blazars 0215+015 and 0851+202 (also known as OJ287) during two outbursts can be accounted for by the superposition of a variable polarized component and a constant polarized one. For 0215+015 the constant component is the most highly polarized, whereas for OJ287 the reverse is found. Only relatively small changes in the flux of the variable component, together with changes in its degree and position angle of polarization, are needed to account for the variability. We discuss the possible physical identities of the components.