X-ray all-sky monitoring and transient detection using a coded sphere telescope

— We present a design for a hard X-ray all-sky monitor which consists of a spherical structure whose surface is partially covered by circular units which serve the dual purpose of detector and mask elements, forming a coded aperture telescope with full 4π steradian coverage. We demonstrate that a simple practical implementation of this geometry results in an instrument which is capable of measuring the fluxes in the 10−20 keV bandpass of the hundred brightest sources in the sky at least every two days. We also show how this instrument can be used to image burst and transient sources; obtain their positions with arcminute accuracy; and follow their light curves throughout their lifetimes.