The search for optical emission on and before the GRB trigger with the WIDGET telescope

Tamagawa, T. and Usui, F. and Urata, Y. and Abe, K. and Onda, K. and Tashiro, M. and Terada, Y. and Fujiwara, H. and Miura, N. and Hirose, S. and Kawai, N. and Yoshida, A. and Mori, M. and Makishima, K. (2005) The search for optical emission on and before the GRB trigger with the WIDGET telescope. Il nuovo cimento C, 28 (4\5). pp. 771-774. ISSN 1826-9885

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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 wideangle 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.

Item Type: Article
Additional Information: Paper presented at the “4th Workshop on Gamma-Ray Burst in the Afterglow Era”, Rome, October 18-22, 2004.
Uncontrolled Keywords: Ground-based ultraviolet, optical and infrared telescopes ; Photometric, polarimetric, and spectroscopic instrumentation ; γ-ray sources; γ-ray bursts
Subjects: 500 Scienze naturali e Matematica > 520 Astronomia e scienze connesse
Depositing User: Marina Spanti
Date Deposited: 17 Mar 2020 17:32
Last Modified: 17 Mar 2020 17:32

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