XRF 040916
GCN Circular 2732
Subject
XRF 040916: Radio Observations
Date
2004-09-23T15:43:40Z (21 years ago)
Edited On
2025-09-09T18:37:10Z (a month ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
Edited By
courey.elliott@gmail.com
D. A. Frail (NRAO) and A. M. Soderberg (Caltech) report on behalf of a
larger collaboration:
"On 2004 Sept. 23.22 UT we carried out follow-up observations with the
VLA at 8.46 GHz centered on the optical afterglow candidate (GCN 2726)
of XRF 040916 (GCN 2712). Within a circle of 1-arcsec radius there are
no radio sources to a 3-sigma limit of 99 microJy.
No further observations are planned."
GCN Circular 2730
Subject
XRF040916: continuing decay of OT
Date
2004-09-21T12:09:48Z (21 years ago)
Edited On
2025-09-09T18:37:08Z (a month ago)
From
George Kosugi at Subaru Telescope <george@subaru.naoj.org>
Edited By
courey.elliott@gmail.com
G. Kosugi, N. Kawai, A. Tajitsu, and H. Furusawa
on behalf of the Subaru GRB Team:
We have observed the entire HETE error box for XRF040916 (=H3558,
Yamazaki et al., GCN 2712; Yamamoto et al. GCN 2713), with Subaru
Suprime Cam beginning at around 6:00 UT on September 20, 2004 in
z'-, Ic-, Rc-, V-, and B-bands. The observed field was centered
at the proposed OT candidate reported by Kosugi et al. GCN 2726.
The OT was clearly detected in all 5 bands, and shows apparent
decay of flux in Ic-, Rc-, and B-bands compared with our
previous observations on September 18. Rc-band magnitude of OT
at Septempber 20.43 UT was approximately Rc=25.
Composite color images are posted at:
http://www.naoj.org/staff/george/Distribute/XRF040916/XRF040916.html
OT is located at the center of the images.
Due to change of instruments, we cannot continue optical monitoring of
OT with Subaru for the next two weeks. Follow-up optical observation
of the OT is strongly encouraged for possible supernova rebrightening.
This message may be cited.
GCN Circular 2727
Subject
XRF040916, optical observations
Date
2004-09-19T01:48:04Z (21 years ago)
Edited On
2025-09-09T18:37:07Z (a month ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
Edited By
courey.elliott@gmail.com
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have an Ic mosaic of the field for XRF040916
(Yamazaki et al. GCN 2712) taken with the NOFS 1.0m telescope
about an hour earlier than the data reported by
Kosugi et al. (GCN 2726). Their proposed candidate appears
on that mosaic at position
23:00:55.13 -05:38:43.2 J2000
(errors 0.2arcsec) and with magnitude
Ic = 20.51 +/- 0.23
based on the calibration photometry of Henden (GCN 2719).
This would imply a very red object or rapid fading.
GCN Circular 2726
Subject
XRF040916: Optical Transient Candidate by Subaru
Date
2004-09-18T17:51:35Z (21 years ago)
Edited On
2025-09-09T18:37:05Z (a month ago)
From
George Kosugi at Subaru Telescope <george@subaru.naoj.org>
Edited By
courey.elliott@gmail.com
G. Kosugi, N. Kawai, A. Tajitsu, and H. Furusawa
on behalf of the Subaru GRB Team:
We have obtained Rc, Ic, and B-band images covering the entire
error box for XRF040916 (=H4588, Yamazaki et al., GCN 2712;
Yamamoto et al. GCN 2713) with SuprimeCam attached on the
prime-focus of the Subaru 8.2m telescope atop Mauna Kea. We
conducted a preliminary analysis and found a fading object
located at coordinates:
RA: 23:00:55.1 Dec: -05:38:43 J2000
The object was seen to fade in either of Rc, Ic, and B bands.
Observing dates and tentative Rc-band magnitudes of OT are
shown below. Photometric accuracy is roughly +/- 0.2 mag.
--------------------------------------------
Date Magnitude(Rc-band)
Sep.16, 5.6UT 22.3
Sep.16, 8.8UT 22.7
Sep.18, 11.8UT 24.8
This message may be cited.
GCN Circular 2722
Subject
XRF040916, Ic observations
Date
2004-09-17T19:42:36Z (21 years ago)
Edited On
2025-09-09T18:37:01Z (a month ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
Edited By
courey.elliott@gmail.com
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have compared our 3 epochs of Ic imaging using the
NOFS 1.0m telescope for the candidate mentioned by Kilmartin
and Gilmore (GCN 2715). In a similar manner to Wu et al. (GCN 2721),
we find no variability within photometric errors:
UTD Ic err
040916.1869 20.08 0.17
040916.2699 19.83 0.14
040917.2932 19.89 0.09
This photometry is calibrated using the data from
Henden (GCN 2719).
GCN Circular 2721
Subject
XRF040916: optical follow-up observations
Date
2004-09-17T18:51:51Z (21 years ago)
Edited On
2025-09-09T18:37:00Z (a month ago)
From
Kuiyun Huang at IANCU <d919003@astro.ncu.edu.tw>
Edited By
courey.elliott@gmail.com
XRF040916: optical follow-up observations
W.L. Wu, K.Y. Huang, W.H. Ip (NCU)
Y. Urata, T. Tamagawa (RIKEN) report :
"We have observed the optical candidate reported by Kilmaritin et
al. (GCN 2715) with 1.0m telescope at Lulin Observatory (National
Central University, Taiwan). We obtain I-band images with 600 sec
exposure on 2004 16 Sep. 16.68 UT (16.3 hr after burst) and 17
Sep. 12.51 UT (1.5 day after burst). We can not find any variablity for
the source. The brithness of the source are
OT candidate seeing
16 Sep. 16.68 UT I = 19.6 2.0 arcsec
17 Sep. 12.51 UT I = 19.7 2.5 arcsec
The limiting magnitude is around 20.1 which comparison with USNO A.2
red magnitude."
This message may be cited
GCN Circular 2719
Subject
XRF040916, BVRcIc field calibration
Date
2004-09-16T21:28:49Z (21 years ago)
Edited On
2025-09-09T18:36:57Z (a month ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
Edited By
courey.elliott@gmail.com
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have acquired BVRcIc all-sky photometry for
a 11x11 arcmin field centered on the HETE coordinates
(trigger 3558; Yamazaki et al. GCN 2712, Yamamoto et al. GCN 2713)
for GRB/XRF040916 with the USNOFS 1.0-m telescope on one photometric
night. Stars brighter than V=13.5 are saturated and
should be used with care. We have placed the photometric data
on our anonymous ftp site:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/xrf040916.dat
The astrometry in this file is based on linear plate solutions
with respect to UCAC2. The external errors are less than 100mas.
The estimated external photometric error is about 0.03mag
and will be improved with additional calibration nights
if an afterglow is discovered.
As always, you should check the dates on the .dat file prior to
final publication to get the latest photometry. There is
a README file on the ftp directory to give you information
about the procedures used to calibrate these fields.
GCN Circular 2717
Subject
XRF 040916, optical follow-up
Date
2004-09-16T18:39:48Z (21 years ago)
Edited On
2025-09-09T18:36:55Z (a month ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Edited By
courey.elliott@gmail.com
A. de Ugarte Postigo, D. Reverte-Pay�, J. Gorosabel,
S. Guziy, M. Jel�nek, J. V�lchez and A. J. Castro-Tirado
(IAA-CSIC, Granada),
report:
We have taken R-band frames covering the error box
for the long-lasting XRF 040916 detected by HETE-2
(Yamazaki et al., GCN Circ. 2712; Yamamoto et al.
GCN Circ. 2713). A set of five images (300-s exposure
time each) was taken at the 2.5m INT (+WFC) on
La Palma during the time interval 16 Sep (02:50 UT -
04:06 UT, i.e. 2.87-4.05 hr after the burst). No new or
strongly variable object is found in the entire error box
down to R = 21, when comparing with the DSS-2 red.
This message can be quoted.