We are requesting supporting optical, infrared, and radio observations of the high-redshift gamma-ray quasar PKS 0528+134 for a series of XMM-Newton X-ray observations. The campaign specifically targets the current low gamma-ray state of the source, as observed by the Fermi Gamma-Ray Space Telescope. Optical, infrared and radio observations are requested beginning now, until the end of September, with intensified observations during a core period coinciding with the period of XMM-Newton observations, September 8 - 14:

We suggest that optical observers perform observations alternately in two bands (Johnson's B and Cousins' R, if possible, other R filters are also accepted) in order to obtain a B, R, B, R ... series of frames during the available time in each observing night. This allows us to get two simultaneous light curves in the two bands for color variability studies. Exposure times should be chosen in view of a good compromise between high precision and high temporal density. When high precision implies gaps of 15 - 20 minutes in each light curve, we suggest to carry out observations in the R band only. At the beginning and end of the B-R (or R-only) sequence, a complete set of filters B-V-R (Johnson-Cousins when possible) would be very useful to follow the optical spectrum behaviour of the source. A finding chart of the field of PKS 0528+134 is provided by the GASP, including the B, V, and R magnitudes of three comparison stars. All three reference stars should be included in each frame.

We request that all optical/NIR data be submitted as calibrated magnitudes in a simple ASCII table format with Julian date, magnitude, and magnitude error. Light curve data in other wavelength bands are requested as calibrated fluxes (in Jy or JyHz).

For more information and suggestions, please contact Markus Böttcher

All observers interested in participating in the campaign are invited to send a message to the Campaign Manager, Markus Böttcher, and the GASP PI, Massimo Villata, providing information on their instrumentation (telescope, detector, filters) and possible observing periods.