Meet DiRAC’s Postdoctoral Fellow: Joseph Murtagh

I’m Joe, a new DiRAC Postdoctoral Fellow working within the solar system group here at UW. I came over from Queen’s University Belfast in Northern Ireland, where my PhD focused on preparing for the LSST at the Vera C. Rubin Observatory – specifically modeling how many outer solar system objects like Centaurs and Neptune Trojans the survey will detect, and how well we’ll be able to characterize them. 

Joseph Murtagh


Now that Rubin is actually producing data, I’m in the exciting position of being able to test my predictions for the first time. My focus at DiRAC is going to be on using early Rubin observations alongside years of archival survey data to build composite light curves to get a more complete picture of how active outer solar system objects behave, which is something that just hasn’t been possible at this scale before. In parallel, I’m looking forward to comparing real detections against my population-level predictions I built during my PhD, and using both to think about which objects are most in need of targeted follow-up and where best to do that.


Alongside that simulation work, I have also studied real objects like Chiron and 103P using survey data from ATLAS and ZTF, and follow-up observations from facilities like LCO and the Liverpool Telescope in order to probe their activity evolution of many years. From this, I’ve managed to capture the longest continuously monitored and densely sampled active period yet recorded for Chiron over the last 50 years, providing a unique opportunity to study the decay of Centaur activity in real time.