Spectra of GRB 970228 from the Transient Gamma-Ray Spectrometer

D. M. Palmer, T. L. Cline, N. Gehrels +7

Visible afterglow counterparts have now been detected for two GRBs (970228 and 970508) but are absent, with $L_{opt}/L_{\gamma }$ ratios at least two orders of magnitude lower, for other G…