1998A&A...335L...5G

We report the detection of the GRB971214 counterpart in the near-infrared by means of two images in the K'-band taken at Calar Alto only ∼3.5 and ∼5 hours after the gamma-ray event. We detect the transient at K'=18.03±0.18 and K'=18.00±0.22 respectively. Our data seem to indicate the existence of a plateau with duration 1.5≤T≤6.7 hours (between 3.5 and 10.2 hours after the high-energy event). Moreover the power-law decline should be steeper than the one given by the index α_K'=0.45. There is also a change in the slope of the broad-band spectrum at some wavelength between the J and K' bands (possibly around the H-band).