BurstCube: A CubeSat for Gravitational Wave Counterparts

Joint detections between gravitational waves and gamma-ray bursts (GRBs) enables multi-messenger science and allows for constraints on the neutron star equation of state, tests of fundamental physics, and insight into the origin of the prompt emission. To increase the likelihood of these coincident detections, full sky coverage in the gamma-ray regime is needed. BurstCube is a 6U (10 x 20 x 30 cm) CubeSat designed for the detection and localization of GRBs in the 50 keV to 1 MeV energy band. BurstCube will expand sky-coverage and provide astronomical context to gravitational wave events detected by LIGO, Virgo, and KAGRA. The instrument is comprised of four individual detectors positioned at 45° from the other to allow for full unocculted sky coverage. Each detector is comprised of a cesium iodide (CsI(Tl)) scintillation crystal coupled to an array of compact, low-power silicon photomultipliers (SiPMs). BurstCube is currently undergoing integration and test and will be delivered in June of 2022. We present the performance and current status of the mission.