  The angular extension of the gamma-ray image of 3C 279 may be constrained by
studying its solar occultations as suggested by Fairbairn et al. (2010). We
perform this kind of analysis for seven occultations observed by Fermi-LAT in
2008-2014, using the Fermi-LAT Solar System tools. The results are interpreted
in terms of models with extended gamma-ray halo of 3C 279; first constraints on
the size and the flux of the halo are reported.
