We report the detection ( 3 \sigma significance level ) of a strong iron emission line in the X-ray spectrum of the afterglow of GRB 000214 ( “ Valentine ’ s Day Burst ” ) observed by BeppoSAX .
An emission line feature was observed with a centroid energy of 4.7 \pm 0.2 keV which , if interpreted as K \alpha emission from hydrogen-like iron , corresponds to a redshift of z=0.47 .
The intensity ( EW \sim 2 keV ) and duration ( tens of hours ) of the line give information on the distance , from the burst region , of the emitting material ( R \geq 3 \times 10 ^ { 15 } cm ) and its mass ( M \geq 1.4 M _ { \odot } ) .
These results are not easily reconciled with the binary merger and hypernova models for gamma ray bursts , because they require large amounts of mass ( about 1 M _ { \odot } ) , at large distances ( \approx 10 ^ { 16 } \ > cm ) , and at newtonian speeds .