WIDGET is a robotic telescope for monitoring the HETE-2 field-of-view to detect Gamma-Ray Burst optical flashes or possible optical precursors. The system has 62°×62° wide field-of-view which covers about 80% of HETE-2 one with a 2k×2k Apogee U10 CCD camera and a Canon EF 24 mm f/1.4 wide-angle lens without a bandpass filter. WIDGET has been in operation since June 2004 at Akeno observing site where is about 200 km apart from Tokyo. Typical limiting magnitude with S/N = 3 at the site is V = 10mag for 5 seconds exposure and V = 11mag for 30 seconds exposure. We had already six coincident observations with HETE-2 position alerts. It was, however, cloudy for all cases due to rainy season in Japan. The expected number of coincident observations under clear sky is about 5 events per year. We will extend the system in early 2005 for Swift era to monitor optical transients in wider field-of-view, multi-color or polarization modes.
各種検索
サポート
ヘルプ