- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 18 Apr 03 09:59:59 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 2686, Seq_Num: 1
GRB_DATE: 12747 TJD; 108 DOY; 03/04/18
GRB_TIME: 35958.85 SOD {09:59:18.85} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 13.280 [sec] timescale
SC_-Z_RA: 172 [deg]
SC_-Z_DEC: -15 [deg]
SC_LONG: 234 [deg East]
SUN_POSTN: 25.97d {+01h 43m 54s} +10.75d {+10d 45' 03"}
MOON_POSTN: 228.54d {+15h 14m 10s} -17.07d {-17d 04' 13"}
MOON_ILLUM: 96 [%]
COMMENTS: Probable GRB.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 18 Apr 03 10:02:54 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 2686, Seq_Num: 2
GRB_DATE: 12747 TJD; 108 DOY; 03/04/18
GRB_TIME: 35958.85 SOD {09:59:18.85} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 6.080 [sec] timescale
SC_-Z_RA: 172 [deg]
SC_-Z_DEC: -15 [deg]
SC_LONG: 234 [deg East]
WXM_CNTR_RA: 163.781d {+10h 55m 07s} (J2000),
163.823d {+10h 55m 17s} (current),
163.150d {+10h 52m 36s} (1950)
WXM_CNTR_DEC: -7.097d {-07d 05' 47"} (J2000),
-7.114d {-07d 06' 51"} (current),
-6.830d {-06d 49' 46"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 6 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 5.2 Y= 3.0 [sig/noise]
WXM_LC_SN: X= 8.5 Y= 3.0 [sig/noise]
SUN_POSTN: 25.97d {+01h 43m 54s} +10.75d {+10d 45' 03"}
SUN_DIST: 138.23 [deg]
MOON_POSTN: 228.54d {+15h 14m 10s} -17.07d {-17d 04' 13"}
MOON_DIST: 63.80 [deg]
MOON_ILLUM: 96 [%]
GAL_COORDS: 259.27,45.69 [deg] galactic lon,lat of the burst
ECL_COORDS: 167.85,-12.92 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 18 Apr 03 10:03:17 UT
NOTICE_TYPE: HETE S/C_Last
TRIGGER_NUM: 2686, Seq_Num: 3
GRB_DATE: 12747 TJD; 108 DOY; 03/04/18
GRB_TIME: 35958.85 SOD {09:59:18.85} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 6.080 [sec] timescale
SC_-Z_RA: 172 [deg]
SC_-Z_DEC: -15 [deg]
SC_LONG: 234 [deg East]
WXM_CNTR_RA: 163.781d {+10h 55m 07s} (J2000),
163.823d {+10h 55m 17s} (current),
163.150d {+10h 52m 36s} (1950)
WXM_CNTR_DEC: -7.097d {-07d 05' 47"} (J2000),
-7.114d {-07d 06' 51"} (current),
-6.830d {-06d 49' 46"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 6 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 5.2 Y= 3.0 [sig/noise]
WXM_LC_SN: X= 8.5 Y= 3.0 [sig/noise]
SUN_POSTN: 25.97d {+01h 43m 54s} +10.75d {+10d 45' 03"}
SUN_DIST: 138.23 [deg]
MOON_POSTN: 228.54d {+15h 14m 10s} -17.07d {-17d 04' 13"}
MOON_DIST: 63.80 [deg]
MOON_ILLUM: 96 [%]
GAL_COORDS: 259.27,45.69 [deg] galactic lon,lat of the burst
ECL_COORDS: 167.85,-12.92 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 18 Apr 03 11:43:01 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 2686, Seq_Num: 4
GRB_DATE: 12747 TJD; 108 DOY; 03/04/18
GRB_TIME: 35958.84 SOD {09:59:18.84} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 6.080 [sec] timescale
SC_-Z_RA: 170 [deg]
SC_-Z_DEC: -15 [deg]
SC_LONG: 234 [deg East]
WXM_CNTR_RA: 163.721d {+10h 54m 53s} (J2000),
163.763d {+10h 55m 03s} (current),
163.090d {+10h 52m 22s} (1950)
WXM_CNTR_DEC: -6.990d {-06d 59' 22"} (J2000),
-7.007d {-07d 00' 26"} (current),
-6.723d {-06d 43' 22"} (1950)
WXM_MAX_SIZE: 18.00 [arcmin] diameter
WXM_LOC_SN: 9 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.5 Y= 6.5 [sig/noise]
WXM_LC_SN: X= 25.5 Y= 12.0 [sig/noise]
SUN_POSTN: 25.97d {+01h 43m 54s} +10.75d {+10d 45' 03"}
SUN_DIST: 138.16 [deg]
MOON_POSTN: 228.54d {+15h 14m 10s} -17.07d {-17d 04' 13"}
MOON_DIST: 63.89 [deg]
MOON_ILLUM: 96 [%]
GAL_COORDS: 259.11,45.73 [deg] galactic lon,lat of the burst
ECL_COORDS: 167.75,-12.85 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: WXM error box is circular; not rectangular.
COMMENTS: Burst_Validity flag is true.
COMMENTS: WXM data refined since S/C_Last Notice.
- GCN notice #2148
P.A. Price, R. McNaught, G.J. Garradd, M.A. Verrender and T.M. Smith
(RSAA, ANU) report:
We have observed the error-circle of HETE trigger #2686 (GRB 030418) with
the Siding Spring Observatory 40-inch telescope + Direct Imager. Our
observations consisted of 5x300 sec exposures in R-band, commencing at
April 18.51 UT. We identify in our images a source not present on the
DSS2 F or N plates. The source has no apparent proper motion between
our images, and is located at:
RA: 10:54:33.69 Dec: -7:01:40.8 J2000
with an estimated error of 0.5 arcsec. We estimate that the source was
R ~ 18.8 mag at the time of our observations.
Further observations are planned.
This message may be cited.
- GCN notice #2149
P.A. Price, R. McNaught, G.J. Garradd, M.A. Verrender and T.M. Smith
(RSAA, ANU) report:
A finding chart for the GRB 030418 optical afterglow candidate (GCN #2148)
is available from:
http://www.mso.anu.edu.au/~pap/grb030418finder.ps
The offset from star A (marked) to the optical afterglow candidate is
29.02" W, 22.05" S.
This message may be cited.
- GCN notice #2150
P.A. Price, R. McNaught, G.J. Garradd, M.A. Verrender and T.M. Smith
(RSAA, ANU) report:
We have re-observed the GRB 030418 optical afterglow candidate (GCN #2148)
with the Siding Spring Observatory 40-inch telescope + Direct Imager.
Our observations consisted of another 5x300 sec exposures in R-band,
commencing at April 18.61 UT. Comparison of our two epochs reveals that
the source faded by about 1 magnitude between the two observations, being
R ~ 19.8 mag in the second epoch. We therefore believe this source is the
optical afterglow of GRB 030418.
This message may be cited.
- GCN notice #2151
H. Mito, S. Nishiura and Y. Urata on behalf of the Kiso GRB team:
" We have observed the field of GRB030418(=H2686) using the Kiso
observatory 1.05 m Schmidt telescope with near infrared camera KONIC.
The KONIC has circular field of view with 8.5'radius. We started to
observe the center region of HETE S/C_Update (Seq_Num 2) with J, H, Ks
band at 21 min after the burst. The afterglow reported Price et
al. (GCN2148) is out of these images.
We re-pointed to the field including the afterglow position at 69 min
after the burst, . We obtained five J-band images with 300 s
exposures.
We could not identify the afterglow with the limiting magnitude J ~
13 (3 sigma) at the 69 min after the burst. We estimated it comparison
with 2MASS J1054356-070118.
The more accurate analysis are in progress."
This message may be cited.
- GCN notice #2152
W. M. Wood-Vasey, Lawrence Berkeley National Laboratory, using images
obtained by R. Bambery, S. Pravdo, M. Hicks, and K. Lawrence
(Near-Earth Asteroid Tracking project, Jet Propulsion Laboratory),
reports historical upper limits for the optical transient for
GRB 030418 of Price et. al (GCN #2148) from images taken with the
Haleakala MSSS 1.2-m and Palomar Oschin 1.2-m telescopes from
2001 Apr 19 -- 2003 Mar 28.
A co-addition of these images (Haleakala: 2001 Apr 19, May 7, 2002 Jan
8, Jan 14, Feb 4; Palomar: 2002 Feb 7, Feb 17, Mar 9, Apr 8, Apr 19,
May 11, 2003 Mar 28) shows nothing at this location to a combined
limiting magnitude of 22.81 (S/N = 3).
The co-addition is available at:
http://supernova.lbl.gov/~wwoodvas/GRB/#GRB030418
This message may be cited.
All dates UT.
- GCN notice #2153
Smith, D. A., Rykoff, E. S., McKay, T. A. report on behalf of the ROTSE
collaboration:
The ROTSE-IIIa robotic telescope at Siding Springs Observatory, NSW, responded
automatically to the two HETE alerts for this burst, in each case beginning a
~45 minute sequence of unfiltered observations within six seconds of the alert
time stamp, the first of which was 238 s after the burst. Each image sequence
began with 10 5-s images and then continued with 90 20-s images.
The 20-s images reached typical limiting magnitudes of 17.5 calibrated against
the USNO A2.0 catalog in R band, while the 5-second images reached
16.9. Sensitivity was degraded by the full moon. Automated software searched
these frames for variable sources not in the USNO catalog and failed to
identify any counterpart candidates. In particular, no source was initially
detected at the location of the optical counterpart reported by Price et al.
(GCN Circ. 2148).
Co-addition of multiple frames, however, yielded significant detections of the
optical transient. We co-added our 200 observations into groups of ten, and
found that from 10:05:23 to 10:50:05, and again from 11:43:07 to 12:20:42, we
measure the transient to vary irregularly between 18.7 and 17.4, with errors of
order 0.15 mag. This means that from 360 s to 2.3 h after the burst, the
transient showed no evidence for decay, in marked contrast to other bursts that
have been observed at early times, such as 990123 and 021211.
- GCN notice #2158
V. Lipunov, A. Krylov, V. Kornilov, G. Borisov, A. Belinski, I. Chilingarian,
D. Kuvshinov, M.V. Kuznetsov, S. Potanin, V. Vitrischak
Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow
report:
The error box of GRB030418 (HETE 2679) was
observed with MASTER system (280mm, http://observ.pereplet.ru). We
obtained 20 measurements in R filter. Our observations started at Apr 18,
21:00 UT (11 hours after the GRB) and had been lasting for 2.5 hours
up to Apr 18 22:36 UT (12,5 hours after the GRB).
There is no OT brighter than 16.5 (R-band) in error box. Transparency was
quite poor due to low altitude of the field above the horizont.
Our fits-images are available at:
http://observ.pereplet.ru/images/GRB030418/30S9.zip
This message may be cited.
- GCN notice #2168
Optical Observations of GRB 030418 with Magellan
A. Dullighan, N. R. Butler, G. R. Ricker, J. L. Elliot, K. Clancy
(MIT), and D. Osip (Las Campanas Observatory)
report:
On 2003 April 21.01 UT, we observed the optical afterglow (Price et
al; GCN2148) of the HETE-localized GRB 030418 (=H2686) with the
Magellan 6.5 meter Clay telescope at Las Campanas Observatory in
Chile. Our observations consisted of three 300s R-Band images and
one 300s I-Band image, taken with the MagIC instrument. The
afterglow brightness had declined significantly since the
measurement reported in GCN2148, consistent with a power law decay
index = 1.3+/-0.1. The afterglow was still point-like in our images,
with a FWHM of 0.5 arcsec. Our results were as follows:
UT t-t0 (days) Mag
2003-04-21.02 2.60 R=23.64 +/- 0.07
2003-04-21.03 2.61 I=22.60 +/- 0.05
The magnitudes reported above are relative to those of the USNO B1
catalog star at RA = 10h 54m 32.71s, Dec = -07:02:16.4 (J2000), taken
as having R=19.33 and I=18.31. Magnitude errors for the USNO star
were not available, and so are not included in the errors we report
here. Possible errors in the magnitudes of the USNO catalog star
should be taken into account when comparing our afterglow magnitudes
to other measurements. Further observations are planned.
This message may be cited.
- GCN notice #2210
Y. Shirasaki, C. Graziani, T. Donaghy, M. Matsuoka, M. Suzuki, T.
Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi,
T. Tavenner, Y. Nakagawa, D. Takahashi, R. Satoh, and Y. Urata, on
behalf of the HETE WXM Team;
N. Butler, R. Vanderspek, G. Crew, J. Doty, J. Villasenor, G. Monnelly,
T. Cline, J. G. Jernigan, A. Levine, F. Martel, E. Morgan, G.
Prigozhin, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on
behalf of the HETE Operations and HETE Optical-SXC Teams;
G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of
the HETE Science Team;
M. Boer, J-F Olive, J-P Dezalay, C. Barraud and K. Hurley on behalf of
the HETE FREGATE Team;
write:
At 09:59:18.85 UTC (35958.85 s UT) on 18 April 2003, the HETE FREGATE
and WXM instruments detected event H2686, a long, X-ray-rich GRB.
The burst triggered FREGATE in the 30-400 keV energy band. The WXM
flight localization was correct and was reported in a GCN Notice at
10:02:54 UTC, 215 sec after the beginning of the burst.
Ground analysis of the WXM data produced a refined location, which was
reported in a GCN Notice at 11:43:01 UTC, 104 minutes after the
beginning of the burst. The WXM ground localization SNR was 9. The
WXM localization can be expressed as a 90% confidence circle that is 9
arcminutes in radius and is centered at:
R.A. = 10h 54m 53s, Dec. = -06d 59' 22" (J2000).
The SXC was off because of illumination by the full moon.
The T_90 duration of the burst in the 30-400 keV band was ~ 135 s. The
fluence of the burst was ~ 1.2 x 10^-6 erg cm^-2 in the 2-25 keV energy
band and ~ 2.5 x 10^-6 erg cm^-2 in the 30-400 keV energy band; thus
S(2-25)/S(30-400 keV) ~ 0.5. Therefore this burst is an X-ray-rich
GRB.
A light curve and skymap for GRB030418 is provided at the following
URL:
http://space.mit.edu/HETE/Bursts/GRB030418
- GCN notice #2216
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 at the coordinates
of the optical transient (Price et al. GCN 2148)
for the HETE burst GRB030418 (H2686; Shirasaki et al. GCN 2210)
with the USNOFS 1.0-m telescope on one marginal 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/grb030418.dat
The astrometry in this file is based on linear plate solutions
with respect to UCAC2. The external errors are less than 100mas.
Due to drifting smoke from prescribed forest fires, the external
photometric error is potentially larger than normal. We will
acquire additional photometry in the next week or so to
reduce the external error.
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 notice #2236
GRB 030418: Second Epoch Optical Observations with Magellan
A. Dullighan, N. R. Butler, G. R. Ricker, J. L. Elliot, K. Clancy
(MIT), and D. Osip (Las Campanas Observatory)
report:
On 2003 April 25.00 UT, we observed the optical afterglow (Price et
al; GCN2148) of the HETE-localized GRB 030418 (Shirasaki et al;
GCN2210) with the Magellan 6.5 meter Clay telescope at Las Campanas
Observatory in Chile. Our observations consisted of two 400s R-Band
images, one 400s I-Band image, and one 400s V-Band image taken with
the MagIC instrument.
The afterglow declined in brightness with respect to our previous
measurements (Dullighan et al; GCN2168). The R band data is
consistent with a revised power law decay index = 1.2 +/- 0.1, when
the two data points from Price et al. (GCN2148 and GCN2150) are
included. The afterglow was still point-like, but very close to the
limiting magnitudes of the images. No evidence of a host galaxy is
observed. We can, however, place a limit on the redshift of the
afterglow of z<~5, due to the small V-R color difference we observe
(i.e., no evidence for a Lyman alpha break). Our second epoch results
were as follows:
UT t-t0 (days) Mag
2003-04-25.00 6.58 R=24.9 +/- 0.4
2003-04-25.01 6.59 I>24 (limiting magnitude)
2003-04-25.02 6.60 V=25.1 +/- 0.5
The magnitudes reported above are referenced to the photometry
reported by A. Henden (GCN2216). We have also recalibrated the
magnitudes we reported in GCN 2168 to A. Henden's photometry
(GCN2216). The errors in calculating relative magnitudes have now
been taken into account. Our revised first epoch results are as
follows:
UT t-t0 (days) Mag (Original) Mag (Revised)
2003-04-21.02 2.60 R=23.64 +/- 0.07 R=23.3 +/- 0.1
2003-04-21.03 2.61 I=22.60 +/- 0.05 I=23.0 +/- 0.1
This message may be cited.
- GCN notice #2284
P. Ferrero and G. Pizzichini (IASF-CNR, Bologna),
C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University),
and A. De Blasi (Bologna Astronomical Observatory) report:
On 2003, April 18 we observed the optical afterglow of HETE GRB
030418 (Shirasaki et al., GCN 2210, Price et al., GCN 2148) with
the 152 cm telescope in Loiano in V, Rc and I.
Using the star at RA 163.623207 Dec -7.039357 , R = 19.852 +/- 0.245
reported by Henden (GCN 2216), in unfavorable conditions due to the
moon, we obtained the following R magnitudes:
exp time starting time (UT) mag
(2 X 600 sec, co-added) 19:31:05 and 19:44:50 R = 20.50 +/- 0.30
(2 X 600 sec, co-added) 20:10:03 and 20:23:05 R = 20.65 +/- 0.29
Our images in .jpg form can be retrieved by sftp using
hostname: ermione.bo.astro.it
username: publicGRB
password: GRB_bo
where a log of our recent observations of GRBs error boxes and OTs in
Loiano can also be found. We plan to update it by adding the list of
previous observations.
This message may be cited.
- Early light curve (from Rykoff et al,
ApJ 601, 1013)
Early-time light curve for GRB 030418. The optical emission rises during the first 600 s, slowly varies
for 1400 s, and then fades as a power law. The triangles are unfiltered ROTSE-IIIa data, the mult crosses
are unfiltered SSO 40 inch data, and the squares are R-band SSO 40 inch data.