We present a comprehensive study of the z = 0.43 host galaxy of GRB 990712 , involving ground-based photometry , spectroscopy , and HST imaging .
The broad-band U BV RI J H K s photometry is used to determine the global spectral energy distribution ( SED ) of the host galaxy .
Comparison with that of known galaxy types shows that the host is similar to a moderately reddened starburst galaxy with a young stellar population .
The estimated internal extinction in the host is A _ { V } = 0.15 \pm 0.1 and the star-formation rate ( SFR ) from the UV continuum is 1.3 \pm 0.3 M _ { \normalsize \odot } \ > yr ^ { -1 } ( not corrected for the effects of extinction ) .
Other galaxy template spectra than starbursts failed to reproduce the observed SED .
We also present VLT spectra leading to the detection of H \alpha from the GRB host galaxy .
A SFR of 2.8 \pm 0.7 M _ { \normalsize \odot } \ > yr ^ { -1 } is inferred from the H \alpha line flux , and the presence of a young stellar population is supported by a large equivalent width .
Images from HST/STIS show that the host has two separate knots , which could be two distinct star-forming regions .