Novae are thermonuclear explosions that occur on the surface of a white dwarf following the accretion of matter from a nearby companion star. The authors seek to understand the geometry and velocity of the ejected material.
V1309 Sco first caught astronomers attention in 2008, when it displayed an outburst, suddenly getting a hundred times brighter. Due its location near the Galactic center, V1309 Sco has been monitored by the OGLE, which is looking for microlensing events, since 2001. The authors of this paper were able to look back into this archive of data and see what V1309 Sco was doing before it erupted.