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First year results from LOTIS

Description: LOTIS (Livermore Optical Transient Imaging System) is a gamma-ray burst optical couterpart search experiment located near Lawrence Livermore National Laboratory in California. The system is linked to the GCN (GRB Coordinates Network) real-time coordinate distribution network and can respond to a burst trigger in 6-15 seconds. LOTIS has a total field-of-view of 17.4 degrees x 17.4 degrees with a completeness sensitivity of mv {approximately} 11 for a 10 second integration time. Since operations began in October 1996, LOTIS has responded to over 30 GCN/BATSE GRB triggers. Seven of these triggers are considered good events subject to the criteria of clear weather conditions, {lt}60 S RESPONSE TIME, AND {gt}50% coverage of the final BATSE 3(sigma) error circle. We discuss results from the first year of LOTIS operations with an emphasis on the observations and analysis of GRB 971006 (BATSE trigger 6414).
Date: November 17, 1997
Creator: Williams, G.G.; Parks, H.S. & Ables, E.
Partner: UNT Libraries Government Documents Department

Instrumentation of LOTIS: Livermore Optical Transient Imaging System; a fully automated wide field of view telescope system searching for simultaneous optical counterparts of gamma ray bursts

Description: LOTIS is a rapidly slewing wide-field-of-view telescope which was designed and constructed to search for simultaneous gamma-ray burst (GRB) optical counterparts. This experiment requires a rapidly slewing ({lt} 10 sec), wide-field-of-view ({gt} 15{degrees}), automatic and dedicated telescope. LOTIS utilizes commercial tele-photo lenses and custom 2048 x 2048 CCD cameras to view a 17.6 x 17.6{degrees} field of view. It can point to any part of the sky within 5 sec and is fully automated. It is connected via Internet socket to the GRB coordinate distribution network which analyzes telemetry from the satellite and delivers GRB coordinate information in real-time. LOTIS started routine operation in Oct. 1996. In the idle time between GRB triggers, LOTIS systematically surveys the entire available sky every night for new optical transients. This paper will describe the system design and performance.
Date: March 6, 1998
Creator: Park, H.S.; Ables, E.; Barthelmy, S.D.; Bionta, R.M.; Ott, L.L.; Parker, E.L. et al.
Partner: UNT Libraries Government Documents Department

Super-LOTIS/LOTIS/LITE: Prompt GRB Followup Experiments

Description: LOTIS (Livermore Optical Transient Imaging System) and Super-LOTIS are automatic telescope systems that measure very prompt optical emission occurring within seconds of the gamma-ray energy release during a Gamma Ray Burst (GRB). Unlike hour-to-days delayed afterglow measurements, very early measurements will contain information about the GRB progenitor. To accomplish this, we developed and have been operating automated telescopes that rapidly image GRB coordinate error boxes in response to triggers distributed by the GRB Coordinate Distribution Network (GCN). LOTIS, located in California, consists of 4 cameras each with a different astronomical filter (B, V, R, open) that can respond to GRB triggers within 5 s. Super-LOTIS can point to any part of the sky within 30 s upon receipt of a GCN trigger and its sensitivity is as deep as V = 17-19 depending on the integration times. Since the shutdown of the CGRO, there has been no real-time GRE3 triggers that enable the LOTIS systems to measure real-time GRE3 counterpart fluxes as of May 2001. This paper describes performance of these systems. We also present our plan to replace the current optical CCD camera on the Super-LOTIS to a near infrared camera to be able to probe dusty GRB environment.
Date: June 25, 2001
Creator: Park, H S; Ables, E; Barthelmy, S; Bradshaw, M; Cline, T; Gehrels, N et al.
Partner: UNT Libraries Government Documents Department