I didn't want to hog the intro thread, so I assumed that Lucas had asked the resident magi if they wanted to come and meet the new guy at a small reception. We all live within walking distance of the keep. I figured at least some of the magi might take a half hour to meet the newest member of the covenant.
A solar is what they called the personal living quarters of the important residents of a castle - think of it as a medieval living room (though it might often double as a bedroom). We haven't offered a lot of detail as to what the inside of the keep looks like. I was making some assumptions. We know it has four towers, one of which is the library (and probably the scholars and scribes) and three of which are devoted to magi. I assume it has a great hall and a meeting room for the magi. It makes sense that it would have a room for our healers as well. It's also likely where our guest quarters are. Finally, it must have some kind of solar - or living area for the magi. Given it's size, I assumed two solars - one just for the magi and one for everyone important enough to warrant being allowed in a solar (i.e., not servants).
In any case, that was my thinking.