The Moon Burst Energetics All-sky Monitor (MoonBEAM) CubeSat, a Gamma-ray Burst Detector for Cislunar Orbit

Abstract:

The Moon Burst Energetics All-sky Monitor (MoonBEAM) CubeSat concept aims to deploy gamma-ray detectors in cislunar space to increase gamma-ray burst (GRB) detections and improve GRB localization precision using the timing-triangulation technique. A gamma-ray instrument in cislunar orbit will detect more GRBs compared to instruments in low Earth orbit because of greatly reduced sky blockage. Working in conjunction with another instrument in low Earth orbit, MoonBEAM can also constrain the arrival direction of the wavefront to an annulus on the sky by utilizing the light arrival times between the two widely-separated instruments. This method has been demonstrated by the Interplanetary Gamma-Ray Burst Timing Network. However, delays in data downlink for instruments outside the range of the Tracking and Data Relay Satellite network prevent rapid follow-up observations. We present here a gamma-ray CubeSat concept in Earth-Moon L3 halo orbit that is capable of faster response and providing a timing baseline for localization improvement. This instrument would aid in the gravitational wave follow-up observations, and assist in the identification of the gamma-ray burst afterglows and kilonova emissions in other wavelengths. Reducing the localization uncertainty makes identifying afterglows much faster, enabling rapid identifications and key early observations that can distinguish between kilonova types. Improved localizations will also prevent source confusion between transients and enable reliable associations. A gamma-ray detection could also increase the confidence in a simultaneous but marginal gravitational wave signal, extending the detection horizon.