No abstract

A nanosatellite to investigate the brightness oscillations of massive luminous stars by differential photometry is currently being developed by a Canadian/Austrian team within the BRITE (BRIght Target Explorer) project. The first Austrian satellite which is funded by the Austrian Space Program, called TUGSAT-1/BRITE-Austria, builds upon the technologies of the Canadian CanX-2 nanosatellite and experience from the highly successful MOST mission. The satellite makes use of recent advances in miniaturized attitude determination and control systems. Precision three-axis stabilization by small reaction wheels and a star tracker provides the necessary accuracy for the photometer telescope to the arcminute level. This will provide astronomers with photometric data of unprecedented precision of massive stars; data which cannot be obtained from the ground due to limitations imposed by the terrestrial atmosphere. The paper describes the spacecraft characteristics and the ground infrastructure being established in support of the BRITE mission as well as a constellation of up to four nearly identical satellites that will carry out long-term observation of stars (magnitude +3.5) not only with respect to brightness variations, but also in different spectrum ranges.