Search

We present multiwavelength observations of the optically flaring source SWFIT J195509+261406 (initially mimicking a GRB), and discuss its nature considering several possibilities, amongst them an ultracompact low‐mass X‐ray binary. Finally we suggest a likely magnetar nature implying a missing link to the dim isolated neutron stars.

LOTIS (Livermore Optical Transient Imaging System) and Super‐LOTIS are automatic telescope systems that search for prompt optical emission from gamma‐ray bursts (GRBs). Both systems are capable of responding to the Gamma‐ray burst Coordinate Network (GCN) triggers within seconds. These systems have been monitoring the GCN real‐time data for automatic HETE2 GRB triggers since HETE2’s launch. In this paper, we present the systems’ capability and current status. We also present the result of the GRB010921 afterglow detection that was localized by HETE2 and the IPN.

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.