We report on multi-band ( UBVRIZJ _ { s } K _ { s } ) observations of the host galaxy of the April 18 , 2000 gamma-ray burst .
The Spectral Energy Distribution ( SED ) is analysed by fitting empirical and synthetic spectral templates .
We find that : ( i ) the best SED fit is obtained with a starburst template , ( ii ) the photometric redshift is consistent with the spectroscopic redshift , ( iii ) the colours of the host are inconsistent with an old stellar population , and ( iv ) the global extinction is constrained to be in the range A _ { V } = 0.12 – 0.61 mag .
The derived global extinction agrees with the one reported for the afterglow ( A _ { V } = 0.4 – 0.9 mag ) , suggesting a homogeneous distribution of the interstellar medium ( ISM ) in the host galaxy .
These findings are supplemented by morphological information from Hubble Space Telescope ( HST ) imaging : the surface brightness profile is smooth , symmetric and compact with no underlying structures ( like dust lanes , spiral arms or disks ) .
A natural scenario which accounts of all the above results is a nuclear starburst that harbours a young population of stars from which the GRB originated .