TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  654
SUBJECT: GRB000418, K'-band photometry
DATE:    00/04/28 18:11:26 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

B. Stecklum, S. Klose (Thueringer Landessternwarte Tautenburg), 
O. Fischer (Universitaets-Sternwarte Jena),
J. Gorosabel (DSRI, Copenhagen),  
C. Sanchez-Fernandez (LAEFF-INTA, Madrid),
A. Castro-Tirado (LAEFF-INTA, Madrid, and IAA-CSIC, Granada), 
D. Butler (Max-Planck-Institut fuer Extraterrestrische Physik, Garching),
S. Hippler, Th. Ott, M. Kasper, R. Weiss
   (Max-Planck-Institut fuer Astronomie, Heidelberg),
L. Montoya, A. Aguirre (Max-Planck-Institut fuer Astronomie, Heidelberg, 
   and Calar Alto observatory),
A. Henden (USRA/USNO), on behalf of the USNO GRB team,
D. H. Hartmann (Clemson University, Clemson), and
J. Greiner (AIP Potsdam)


report:

As a supplement to our previous GCN report (Klose et al., GCN #645) we
can provide now a more accurate estimate of the K'-band magnitude of
the afterglow of GRB 000418. It is based on the assumption that the
B-R colours of three USNO stars on the detection image are
representative for their spectral types. A value of K' = 17.5 was
found with an uncertainty of 0.5 mag.

In addition, in GCN #645 one should read: The limiting magnitude of the 
(3.5-m) K'-band images is about 18.5.

This message is quotable.