We observed with ISO the region of the sky containing the entire BeppoSAX GBR error box for GRB 970402. Two target-of-opportunity observations were carried out as a result of the rapid BeppoSAX detection of the event. The main result is that with the exception of the variable star BL Cir, none of the 40 objects within the GRB error box displayed significant variability Therefore no strong additional and variable emission appeared following the X-ray afterglow, allowing strict upper limits to be placed on the variable IR emission at 12 µm and 174 µm. There is a possibility of detecting a fading (or faded) source in a future ISO observation. There are plans for further observations of GRB error boxes.
© European Southern Observatory (ESO) 1998
Online publication: January 8, 1998