The Optical Afterglow of Grb 971214: R and J Photometry

We present an R-band and J-band photometry of an optical transient which is likely to be associated with the gamma-ray burst event GRB 971214. Our first measurement took place 13 hours after the gamma-ray event. The brightness decayed with a power-law exponent α = −1.20 ± 0.02, which is similar to those of GRB 970228 and GRB 970508 which had exponents of α = −1.10 ± 0.04 and α = −1.141 ± 0.014 respectively. The transient decayed monotonically during the first four days following the gamma-ray event in contrast with the optical transient associated with GRB 970508 which increased in brightness, peaking two days after the burst, before settling to a power-law decay.