Radio and Optical Follow-up Observations and Improved Interplanetary Network Position of GRB 970111

Abstract

We report on Westerbork 840 MHz and 1.4 and 5 GHz radio observations of the improved Interplanetary Network Wide Field Camera (IPN WFC) error box of the γ-ray burst GRB 970111, between 26.4 hr and 120 days after the event onset. In the ∼13 arcmin2 area defined by the IPN (BATSE and Ulysses) annulus and the published refined BeppoSAX WFC error box, we detected no steady sources brighter than 0.56 mJy (4 σ) and no varying radio emission, down to 1.0 mJy (4 σ). We also report on B-, V-, R-, and I-band observations of the error box with the 4.2 m William Herschel Telescope at La Palma. © 1997. The American Astronomical Society. All rights reserved.