A Soft X-ray Sky Monitor, Transient Finder, and Burst Detector for High-energy and Multimessenger Astrophysics

The BlackCAT CubeSat is an X-ray coded aperture telescope observatory, with an expected launch in 2024, that is designed for observations of bright X-ray sources in the 0.5–20 keV band. The instrument will have a wide field of view (0.9 steradian) and be capable of catching gamma ray bursts from the distant universe, galactic transients, and flares from blazars, while simultaneously monitoring the X-ray sky for rare and exciting events including gravitational wave X-ray counterparts, magnetar flares, supernova shock breakouts, and tidal disruption events. The mission will thus function as a multi-wavelength and multi-messenger complement to multiple present and future facilities including LIGO, VIRGO, KAGRA, IceCube, KM3NET, LSST, LOFAR, SKA, and CTA. Rapid notifications of burst positions would be transmitted to the ground and relayed to the GCN network. The name BlackCAT is derived from its scientific emphasis on black-hole-related transient events being observed with a Coded Aperture Telescope (CAT). BlackCAT will serve as the scientific payload aboard a commercial 6U CubeSat spacecraft. X-ray hybrid CMOS detectors will form the focal plane array. In addition to carrying out its mission lifetime science programs related to distant GRBs, transients, and X-ray sky monitoring, BlackCAT will also serve as a pathfinder for future economical missions combining multiple BlackCAT modules on either a single small satellite or on multiple CubeSats, thus providing a high-duty-cycle and expanded field-of-view monitoring network. The BlackCAT design, as well as an overview of mission plans and science, will be presented.