TITLE:   GCN CIRCULAR
NUMBER:  7157
SUBJECT: GRB 071227: optical afterglow
DATE:    08/01/02 10:19:36 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, S. Covino, D. Fugazza, G. Tagliaferri (INAF-OAB), G. 
Chincarini (Univ. Bicocca), S. Piranomonte, V. D'Elia, L. Stella 
(INAF-OAR) and A. Moretti (INAF-OAB) report, on behalf of the MISTICI 
collaboration:

We observed again the field of the short GRB 071227 (Sakamoto et al., 
GCN 7147; Sato et al. GCN 7148 and GCN 7156) with the ESO-VLT equipped 
with the FORS2 camera in imaging mode on Dec 31.2147. We compared our 
images with respect to our first epoch of observations (Dec 28.1328; 
D'Avanzo et al., GCN 7152). Image subtraction performed with the ISIS 
package on our two sets of images clearly shows the presence of an 
optical afterglow inside the refined XRT error box (Beardmore et al., 
GCN 7153). This object is clearly associated to the candidate host 
galaxy (Berger et al. 7151; D'Avanzo et al. GCN 7152). The coordinates 
of the afterglow are (J2000):

R.A. = 03:52:31.26
Dec. = -55:59:03.5

with an uncertainty of 0.3". The afterglow is located at about 3.1" from 
the bulge, which corresponds to about 16.1 kpc at z=0.383 (D'Avanzo et 
al. GCN 7152; Berger et al. GCN 7154).

A figure showing the result of the subtraction can be found at the 
following URL:

http://www.brera.inaf.it/utenti/davanzo/public/grb/GRB071227/GRB071227_subtraction.jpg 



We acknowledge support from the ESO staff.