We would like to thank S. Beckwith of the Space Telescope Science Institute for making the HST /STIS observations of GRB 990123 available to the astronomical community. We would also like to thank H. Ferguson for his useful comments. S. H. is supported by the Danish Centre for Astrophysics with the HST . This work was supported by the Danish Natural Science Research Council.
© European Southern Observatory (ESO) 1999
Online publication: March 29, 1999