GCN Circular 633
Subject
GRB 000408, optical observations
Date
2000-04-10T22:44:36Z (25 years ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
A. Henden (USRA/USNO), C. Luginbuhl (USNO),
B. Canzian (USNO) on behalf of the USNO GRB Team,
Vijay Mohan, S. B. Pandey and Ram Sagar, UPSO (Nainital),
David Alcalde and David Martinez-Delgado, IAC (Tenerife),
Jose Maria Castro Ceron, ROA (San Fernando),
Alberto Castro-Tirado,
LAEFF-INTA (Madrid) and IAA-CSIC (Granada),
and Javier Gorosabel Urkia, DSRI report:
We have observed the entire preliminary IPN
error box for GRB 000408 (GCN#626) as well
as the refined error box (GCN#632)
from several sites and on both available nights.
Because of the shape of the error box, mosaics were
used at each site, limiting the depth of exposure
for any particular field. Only R-band observations
were made. A log of the observations is given below.
TEL. MARCH (UT) TEXP RA DEC
--------------------------------------------------
IAC80 8.9352 -- 9.0103 3800 9:10:41 +66:34:15
IAC80 9.0094 -- 9.0140 200 9:09:39 +66:34:15
IAC80 9.0141 -- 9.0187 200 9:08:39 +66:34:47
IAC80 9.0176 -- 9.0223 200 9:07:42 +66:35:15
IAC80 9.0210 -- 9.0257 200 9:06:41 +66:35:47
IAC80 9.0248 -- 9.0294 200 9:11:41 +66:34:50
IAC80 9.0292 -- 9.0338 200 9:12:40 +66:34:21
IAC80 9.0327 -- 9.0373 200 9:13:42 +66:33:52
IAC80 9.0360 -- 9.0407 200 9:14:41 +66:33:20
IAC80 9.0360 -- 9.0407 200 9:14:41 +66:33:20
IAC80 9.9319 -- 9.9741 3600 9:08:26 +66:33:28
UPSO 9.7667 -- 9.7724 500 9:48:41 +66:35:15
UPSO 9.7764 -- 9.7821 500 9:10:27 +66:35:08
USNO 9.136 -- 9.225 1800 9:13:41 +66:33:51
USNO 9.128 -- 9.216 1800 9:12:02 +66:33:51
USNO 9.121 -- 9.209 1800 9:10:20 +66:33:51
USNO 9.145 -- 9.233 1800 9:08:41 +66:33:51
USNO 9.153 -- 9.241 1800 9:07:01 +66:33:51
USNO 10.154 -- 10.176 1800 9:13:41 +66:33:51
USNO 10.176 -- 10.198 1800 9:12:02 +66:33:51
USNO 10.130 -- 10.152 1800 9:10:20 +66:33:51
USNO 10.199 -- 10.229 1800 9:08:41 +66:33:51
USNO 10.229 -- 10.251 1800 9:07:01 +66:33:51
POSS-II/F for this field is not available through
DSS. However, it is available through the USNO
PMM pixel database. We have placed three files
on the anon ftp server that cover the error box:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-1.jpg
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-2.jpg
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-3.jpg
in order of increasing RA. A finder chart from POSS-I
with the refined error box marked on it is at:
http://www.dsri.dk/~jgu/grb000408/grb000408.dss.gif
No candidate was found above the POSS-II plate limit.
The two deep exposure sets from USNO were blinked
to look for transients below the POSS-II plate
limit. While several candidates are present,
none is entirely convincing at a limiting
magnitude of approximately R=21.5. However, for
completeness, here are the two best candidates
inside the error box, both R=20.5 or fainter:
A 09:11:04.82 +66:33:31.3 J2000
B 09:08:51.36 +66:33:36.5 J2000
Preliminary BVRI all-sky calibration of the central
part of the error box can be found at
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408.dat
The external zero-point errors for this file are estimated
to be +/- 0.05mag. Refinement of this photometry
will be performed in late April if an OT is discovered.
Further data analysis is in progress.
[GCN OPS NOTE (11 Apr 00): The co-authors S.B.Pandey & David Martinez-Delgado
were added to the list.]