Hi, what I know about 3C279 is: 3C279 is a OVV (optical violently variable) quasar that we look at face on, so much that we are in the line of sight of the relativistic jet. That's why it is also refered to as a blazar.. Its redshift is indicated as z=0.538. This is quite large, therefore 3C279 is considered to be quite remote. How far exactly? I bet is more than a billion l.y. away... The observed variability of such a blazar is caused by its internal increased activity (increased accretion?) and / or the precession of the jet... Which of those is the most likely one considering the timescales of events like the one now? Follow-up observations will certainly help in assessing this. Maybe someone cares to comment ... Regards, Berto Monard, Pretoria