TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2777
SUBJECT: GRB041006 (=HETE3570): optical observations
DATE:    04/10/07 03:03:23 GMT
FROM:    Patrizia Ferrero at IASF/CNR,Bologna  <ferrero@bo.iasf.cnr.it>

P. Ferrero (IASF/CNR, Bologna; Osservatorio e Universita' di Teramo),
C. Bartolini, G. Greco, A. Guarnieri, A. Piccioni (Universita' di Bologna),
E. Mazzotti Epifani (INAF, Oss. di Capodimonte - Napoli), R. Gualandi 
(INAF, Bologna Observatory) and G. Pizzichini (IASF/CNR, Bologna) report:

we observed the OT of GRB 041006 (=HETE3570) reported by Da Costa, Noel 
and Price (GCN 2765).
By comparison with USNOA.2  star U0900_00213019, at R.A.= 00h 54m 43.41s
DEC.= +01d 15' 45.73", R mag=19.3  and  USNOB.1 star 0912-0009780, at
R.A.= 00h 54m 43.38s DEC.= +01d 15' 45.38", I mag= 18.57 , we obtain:


mean UT             filter                 exposure            mag
Oct. 6.8393           Rc                      900s             19.7
Oct. 6.8506           Rc                      900s             19.7
Oct. 6.8637           Rc                      900s             19.8
Oct. 6.8751           Ic                      900s             19.35
Oct. 6.9627           Rc                     4x900s            19.95


Magnitude errors are dominated by those on the magnitude of the 
comparison star, probably ~ 0.3 mag in both filter (Monet et al. 2003, 
ApJ 125, 984). The seeing was ~ 3".

Our images shall be available as soon as possible on a public directory 
from where it will be possible to retrieve by sftp using the hostname: 
ermione.bo.astro.it, username: publicGRB, password: GRB_bo and 
directory: GRB041006.

This message may be cited.