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.
This paper describes an incredibly variable brown dwarf. To fit this variability with models, a combination of thick clouds and clearer areas are needed. This means that there are big dusty storms that cover large fractions of 2M2139’s surface!
Improving stellar astrophysical measurements will help us to better characterize exoplanets. The interferometric observational techniques applied here allow scientists to precisely measure the stellar parameters (including star’s radius) of a nearby system with exoplanets, including a transiting super-Earth.