GCN Circular 704

Stephen Holland, Johan Fynbo, Bjarne Thomsen (University of Aarhus),
Michael Andersen (University of Oulu),
Gunnlaugur Bjornsson (University of Iceland),
Jens Hjorth (University of Copenhagen),
Andreas Jaunsen (University of Oslo),
Priya Natarajan (University of Cambridge, & Yale), and
Nial Tanvir (University of Hertfordshire)

	We have obtained 1240 seconds of STIS images with the 50CCD
(clear) aperture and 1185 seconds with the F28X50LP (long pass)
aperture of the host galaxy of GRB 980425.  This data was taken as
part of the Survey of the Host Galaxies of Gamma-Ray Bursts (Holland
et al. GCN 698
Not found
 
 
) approximately 778 days after the burst.  Combined
images are now available at
"http://www.ifa.au.dk/~hst/grb_hosts/data/index.html" and a GIF image
of the host galaxy is available at
"http://www.ifa.au.dk/~hst/grb_hosts/data/grb980425_colour.gif".

	An astrometric solution from VLT V-, R-, and I-band images
(P.I., B. Libundgut) suggests that the supernova is located at X = 987
+/- 2, Y = 1064 +/- 2 on our drizzled long pass image.  This is in an
extended object with AB magnitudes of 26.2 +/- 0.1 in the STIS clear
filter and 26.3 +/- 0.1 in the STIS long pass filter.  An
extrapolation of the V-band late-time light curve of SN 1998bw
(McKenzie & Schaefer 1999, PASP, 111, 964) suggests that the SN
remnant will have a magnitude of ~28.4 in the clear filter, which is
near the detection limit of our data.  The extended object has a
full-width at half-maximum, in the long pass image, of 0.13
arcseconds.  When the resolution limit (0.088 arcsec) is taken into
account the object has a diameter of, at most, ~0.09 arcsec.  For z =
0.0085, and a cosmology with H0 = 65, Omega_matter = 0.2 and
Omega_lambda = 0, this corresponds to a diameter of less than ~17 pc.
The colour and size of the object is consistent with it being a young
star cluster.  The extended object is embedded in a large extended
feature (possibly an HI region) with a diameter of ~75 pc and an
estimated colour of V-R ~= 0.7 +/- 0.3.  A GIF image of the region
containing the supernova is available at
"http://www.ifa.au.dk/~hst/grb_hosts/data/grb980425cd_sfr.gif".  A
detailed analysis of these images is in progress (Holland et al. 2000,
in preparation).