Tuesday was the day for productivity, but Thursday was the day for learning.

I now understand what T90 and T50 algorithms are, how they're calculated, and what they're importance is. They are used to make a measurement of the duration of a burst. The burst durations fall into two classes (short bursts under 2 seconds and long bursts over 2 seconds) with some overlap. The energy distribution of short bursts are harder (that is, more energetic) than long bursts. The current models are that short bursts and long bursts originate from different processes: energetic supernovae explosions cause long GRBs and compact object mergers cause short GRBs.

But on June 14, a long (undeniably long – 105 seconds or so, at the very least 50 seconds) burst occurred that was found to be harder, more characteristic of a short GRB. Even more puzzling, the GRB emission has a high probability of originating inside a galaxy that is close enough so that we should see a supernova from it, but we don't. This GRB throws into question the current classification scheme.

Reading papers is good, but there's nothing like learning from the people who actually did the ground-breaking science. I love Huntsville.