Gamma-ray Burst 030913

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

 
TITLE:          GCN/HETE BURST POSITION NOTICE
NOTICE_DATE:    Sat 13 Sep 03 17:07:01 UT
NOTICE_TYPE:    HETE S/C_Alert 
TRIGGER_NUM:    2849,   Seq_Num: 1
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13  
GRB_TIME:       61617.51 SOD {17:06:57.51} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale   
SC_LONG:        112 [deg East] 
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_ILLUM:     91 [%]
COMMENTS:       No s/c ACS pointing info available yet. 
COMMENTS:       Probable GRB.

GCN/BACODINE POSITION NOTICE

TITLE:          GCN/HETE BURST POSITION NOTICE
NOTICE_DATE:    Sat 13 Sep 03 17:07:35 UT
NOTICE_TYPE:    HETE S/C_Update
TRIGGER_NUM:    2849,   Seq_Num: 2
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13
GRB_TIME:       61617.51 SOD {17:06:57.51} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale
SC_-Z_RA:       313 [deg]
SC_-Z_DEC:        2 [deg]
SC_LONG:        112 [deg East]
WXM_CNTR_RA:    314.508d {+20h 58m 02s} (J2000),
                314.556d {+20h 58m 13s} (current),
                313.859d {+20h 55m 26s} (1950)
WXM_CNTR_DEC:    -2.209d {-02d 12' 32"} (J2000),
                 -2.195d {-02d 11' 40"} (current),
                 -2.403d {-02d 24' 11"} (1950)
WXM_MAX_SIZE:   60.00 [arcmin] diameter
WXM_LOC_SN:     3 sig/noise (pt src in image)
WXM_IMAGE_SN:   X= 3.0 Y= 2.2 [sig/noise]
WXM_LC_SN:      X= 3.7 Y= 3.5 [sig/noise]
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
SUN_DIST:       143.30 [deg]
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_DIST:       70.06 [deg]
MOON_ILLUM:     91 [%]
GAL_COORDS:     46.47,-28.96 [deg] galactic lon,lat of the burst
ECL_COORDS:     316.31,14.36 [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:    Sat 13 Sep 03 17:09:09 UT
NOTICE_TYPE:    HETE S/C_Update
TRIGGER_NUM:    2849,   Seq_Num: 3
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13  
GRB_TIME:       61617.51 SOD {17:06:57.51} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale   
SC_-Z_RA:       313 [deg]
SC_-Z_DEC:        2 [deg]
SC_LONG:        112 [deg East] 
WXM_CNTR_RA:    314.508d {+20h 58m 02s} (J2000),
                314.556d {+20h 58m 13s} (current),
                313.859d {+20h 55m 26s} (1950)
WXM_CNTR_DEC:    -2.209d {-02d 12' 32"} (J2000),
                 -2.195d {-02d 11' 40"} (current),
                 -2.403d {-02d 24' 11"} (1950)
WXM_MAX_SIZE:   60.00 [arcmin] diameter
WXM_LOC_SN:     3 sig/noise (pt src in image)
WXM_IMAGE_SN:   X= 3.0 Y= 2.2 [sig/noise]
WXM_LC_SN:      X= 3.7 Y= 3.5 [sig/noise]     
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
SUN_DIST:       143.30 [deg]   
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_DIST:       70.06 [deg] 
MOON_ILLUM:     91 [%]
GAL_COORDS:     46.47,-28.96 [deg] galactic lon,lat of the burst
ECL_COORDS:     316.31,14.36 [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:    Sat 13 Sep 03 17:10:17 UT
NOTICE_TYPE:    HETE S/C_Update
TRIGGER_NUM:    2849,   Seq_Num: 4
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13
GRB_TIME:       61617.51 SOD {17:06:57.51} UT 
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale
SC_-Z_RA:       313 [deg]
SC_-Z_DEC:        2 [deg]
SC_LONG:        112 [deg East] 
WXM_CNTR_RA:    314.508d {+20h 58m 02s} (J2000),
                314.556d {+20h 58m 13s} (current),
                313.859d {+20h 55m 26s} (1950)
WXM_CNTR_DEC:    -2.209d {-02d 12' 32"} (J2000),
                 -2.195d {-02d 11' 40"} (current),
                 -2.403d {-02d 24' 11"} (1950)
WXM_MAX_SIZE:   60.00 [arcmin] diameter
WXM_LOC_SN:     3 sig/noise (pt src in image)
WXM_IMAGE_SN:   X= 3.0 Y= 2.2 [sig/noise]
WXM_LC_SN:      X= 3.7 Y= 3.5 [sig/noise]     
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
SUN_DIST:       143.30 [deg]   
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_DIST:       70.06 [deg] 
MOON_ILLUM:     91 [%]
GAL_COORDS:     46.47,-28.96 [deg] galactic lon,lat of the burst
ECL_COORDS:     316.31,14.36 [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:    Sat 13 Sep 03 17:10:27 UT
NOTICE_TYPE:    HETE S/C_Last
TRIGGER_NUM:    2849,   Seq_Num: 5
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13
GRB_TIME:       61617.51 SOD {17:06:57.51} UT 
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale
SC_-Z_RA:       313 [deg]
SC_-Z_DEC:        2 [deg]
SC_LONG:        112 [deg East] 
WXM_CNTR_RA:    314.508d {+20h 58m 02s} (J2000),
                314.556d {+20h 58m 13s} (current),
                313.859d {+20h 55m 26s} (1950)
WXM_CNTR_DEC:    -2.209d {-02d 12' 32"} (J2000),
                 -2.195d {-02d 11' 40"} (current),
                 -2.403d {-02d 24' 11"} (1950)
WXM_MAX_SIZE:   60.00 [arcmin] diameter
WXM_LOC_SN:     3 sig/noise (pt src in image)
WXM_IMAGE_SN:   X= 3.0 Y= 2.2 [sig/noise]
WXM_LC_SN:      X= 3.7 Y= 3.5 [sig/noise]     
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
SUN_DIST:       143.30 [deg] 
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_DIST:       70.06 [deg] 
MOON_ILLUM:     91 [%]
GAL_COORDS:     46.47,-28.96 [deg] galactic lon,lat of the burst
ECL_COORDS:     316.31,14.36 [deg] ecliptic lon,lat of the burst
COMMENTS:       Probable GRB.
COMMENTS:       WXM error box is circular; not rectangular.

GCN notice #2381
K. Torii (RIKEN) reports:
"A part of the WXM error region of GRB 030913 (HETE trigger 2849) was observed by the Automated Response Telescope at RIKEN (0.25-m f/6.8 reflector equipped with unfiltered CCD AP6E). The observation started at 2003 September 13, 17:08:24 UT (87 s after trigger), and 40 s integration was repeated.
In a stacked frame (12 x 40 s), no new object brighter than about 14.5 mag (USNO A2.0 red) is identified within the central 30x30 arcminutes area of the WXM position (Seq_Num 2). Further analysis is in progress."

GCN/BACODINE POSITION NOTICE

 
TITLE:          GCN/HETE BURST POSITION NOTICE
NOTICE_DATE:    Sat 13 Sep 03 21:17:38 UT
NOTICE_TYPE:    HETE Ground Analysis
TRIGGER_NUM:    2849,   Seq_Num: 6
GRB_DATE:       12895 TJD;   256 DOY;   03/09/13
GRB_TIME:       61617.50 SOD {17:06:57.50} UT 
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE:     139  [cnts/s]  on a 1.300 [sec] timescale
SC_-Z_RA:       313 [deg]
SC_-Z_DEC:        2 [deg]
SC_LONG:        112 [deg East] 
SUN_POSTN:      171.27d {+11h 25m 05s}   +3.76d {+03d 45' 49"}
MOON_POSTN:      24.10d {+01h 36m 23s}   +7.65d {+07d 39' 04"}
MOON_ILLUM:     91 [%]
COMMENTS:       Definite GRB.
COMMENTS:       There is no position known for this trigger at this time.
COMMENTS:       Burst_Validity flag is true.
COMMENTS:       WXM data refined since S/C_Last Notice.
COMMENTS:       Invalid localization by flight code.

GCN notice #2383
GRB030913 (=H2849): A GRB Possibly Localized by HETE
M. Suzuki, C. Graziani, J. Villasenor, G. Crew, R. Vanderspek, M. Galassi, G. Ricker, D. Lamb, N. Kawai, and S. Woosley on behalf of the HETE Science Team;
G. Prigozhin, J. Doty, A. Dullighan, N. Butler, T. Cline, J.G. Jernigan, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
Y. Shirasaki, M. Matsuoka, T. Tamagawa, T. Sakamoto, A. Yoshida, K. Torii, Y. Nakagawa, D. Takahashi, R. Satoh, Y. Urata, E. Fenimore, and T. Donaghy, on behalf of the HETE WXM Team;
J-L Atteia, C. Barraud, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team;
write:
At 17:06:57.52 UTC (61617.5 s UT) on 13 Sep 2002, the HETE FREGATE, WXM, and SXC instruments detected event H2849, a relatively short GRB. The WXM flight localization was reported in a GCN Position Notice at 17:07:35 UT, 37 sec after the burst. The attitude of the spacecraft experienced a brief period of oscillations at just the time of GRB030913, which degraded the flight Y-detector localization and prevented us from confirming the flight localization to a high level of confidence in initial ground analyses. For this reason, the flight localization was retracted in a GCN Notice sent at 21:18 on 13 Sep 2002.
Further analyses show that it is possible that the flight localization was indeed correct. If you have observed the flight localization, we encourage you to examine it for the afterglow, in case it is correct. The correct Y localization may be recoverable.
The WXM flight localization SNR was 3.0 in the X-detector and 2.2 in the Y-detector. The WXM flight localization can be expressed as a 90% confidence circle that is 30 arcminutes in radius and is centered at
WXM-Ground: RA = +20h 58m 02s, Dec = -02d 12' 32" (J2000).
In the FREGATE 8-40 keV band, 8-80 keV band, and 30-400 keV band, the burst had a duration of ~6 seconds (T90). The burst significance was 12 sigma in the 30-400 keV band, 6 sigma in the WXM 2-25 keV band. Based on preliminatry spectral fits, the 30-400 keV fluence is roughly 6e-7 erg/cm2 and the 7-30 keV fluence is roughly 8e-8 erg/cm2.
Further information (including a light curve) for GRB030913 is provided at the following URL:
http://space.mit.edu/HETE/Bursts/GRB030913
This message is citable.
GCN notice #2385
V. Lipunov, A. Krylov, V. Kornilov, G. Borisov, D. Kuvshinov, A. Belinski, I. Chilingarian, M. Kuznetsov, S. Potanin, V. Vitrischak, G. Antipov
Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow
report:
MASTER system (280mm, http://observ.pereplet.ru) with new AP16E CCD camera with new AP16E CCD camera (~7 square degrees) was pointed automatically after receiving HETE 2849 alert (120 seconds after GRB time). But due to weather and technical conditions the first direct image of the error box area was obtained 43 minutes after GRB. The weather conditions were poor (almost full Moon + cirrus clouds), so the limiting magnitude of the first image was about 13.5 (unfiltered instrumental magnitude). After that we received about 100 images of the 7 square degrees (2.65x2.65 deg) area around the center of error box with limiting magnitude about 16.0. We stopped the data processing after receiving cancellation report from HETE, but after receiving GCN2383 we made the data reduction of 2 images (the 1st and the best). There was no OT detected up to 13.5, 43 minutes after GRB time in a 1 degree circular error box. There was no OT detected up to 16.0, 2h41m after GRB time in the same error box.
Reduced FITS images (dark,bias substracted, flat normalized) are available at http://www.sai.msu.su/~aleks/observ/
These are our first results with new large CCD, so we still have no pipeline to reduct them. But if anybody likes to process these data (about 7 Gigabytes including calibration frames) we can provide an access to them. Submit your requests to lipunov@sai.msu.ru
This message may be cited.
GCN notice #2386
Alain Klotz, Michel Boer (CESR/CNRS/UPS) and Jean-Luc Atteia (LAT/OMP/UPS), on behalf of the TAROT team report:
Following the GCN notices about GRB 030913, and GCNC #2383, The automated TAROT telescope took several images of the possible location of the source of GRB 030913. The images were taken between 20:33 and 20:44 UT on Sept., 13, 2003. No new object is present on the 2 deg. x 2deg. image centered on the GCN notice positon. The Moon is relatively close to the source position (72deg.), hence the limit we could obtain on the possible source magnitude is only R = 17.2
This message is citable.
GCN notice #2388
GRB030913 (=H2849): Confirmation of the Flight Localization
T. Donaghy, M. Suzuki, D. Lamb, G. Ricker, N. Kawai, and S. Woosley on behalf of the HETE Science Team;
G. Prigozhin, J. Doty, A. Dullighan, N. Butler, J. Villasenor, G. Crew, R. Vanderspek, T. Cline, J.G. Jernigan, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
Y. Shirasaki, M. Matsuoka, T. Tamagawa, T. Sakamoto, A. Yoshida, K. Torii, Y. Nakagawa, D. Takahashi, R. Satoh, Y. Urata, E. Fenimore, M. Galassi, on behalf of the HETE WXM Team;
J-L Atteia, C. Barraud, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team;
After extensive ground analysis of the WXM data for GRB030913 (=H2849), we have succeeded in localizing this burst. The WXM localization based on ground analysis can be expressed as a 90% confidence circle that is 12 arcminutes in radius and is centered at
WXM-Ground: RA = +20h 58m 07.4s, Dec = -02d 21' 54" (J2000).
GRB030913 was too faint to be localized by the SXC.
The WXM ground localization confirms the flight localization reported in a GCN Position Notice on 2003 13 Sep at 17:07:35 UT, 37 sec after the burst and in GCN Circular 2383.
Therefore, if you observed the flight localization of GRB030913, we strongly encourage you to examine your observations for the optical afterglow or to set limits on the brightness of any optical afterglow.
Further information for GRB030913, including a light curve and a sky map, is provided at the following URL:
http://space.mit.edu/HETE/Bursts/GRB030913
This message may be cited.
GCN notice #2389
GRB 030913, BOOTES observations
Antonio de Ugarte, IAA-CSIC (Granada) Petr Kubanek and Martin Jelinek, ASU (Ondrejov) Tomas de J. Mateo Sanguino, CEDEA-INTA (Huelva) Rene Hudec, ASU (Ondrejov) Tom=E1s Soria, EELM-CSIC (M=E1laga) Sergei Guziy and Alberto Castro-Tirado, IAA-CSIC on behalf of the BOOTES Team
report:
"Several images of the HETE-II error box for the GRB 030913 (Suzuki et al., GCNC 2383) were obtained right after the sunset as the automatic response to the GRB alert by the BOOTES-2 instruments in Southern Spain. Images were acquired by both the wide-field CCD (35 x 35 deg FOV) and the narrow-field CCD attached to the 0.3-m telescope (30' FOV) starting on Sep 13.797 UT (2-h after the event). Limiting magnitudes of the co- added images for the following 10-min are 12 (I-band) and 17.5 (unfiltered), which cover 100% and 70% of the refined HETE-II error box (Donaghy et al. GCNC 2388) respectively. None of them reveals any new (or strongly variable) source, in agreement with the results obtained by Torii (GCNC 2381), Lipunov et al. (GCNC 2385) and Klotz et al. (GCNC 2386). This is the first event followed up at the BOOTES-2 station. Images are posted at http://laeff.inta.es/BOOTES/ing/results/grb030913.htm
This message is quotable.

GCN notice #2390
Arto Oksanen, Arne Henden, Cristovao Jacques, Andrea Tasselli, Odd Trondal, Michel Bonnardeau and Bruce Gary report on behalf of the AAVSO International High Energy Network:
We have observed the GRB030913 (=H2849) error circle starting September 13, 2003 18:56 UT, less than 2 hours from the burst. The revised error circle (Donaghy et al., GCN 2388), was covered completly by several observers.
The earlier larger error circle (M. Suzuki et al., GCN 2383) was covered by 90 percent in 7.9 hours.
All images vere visually checked and most images were also checked by software against USNOA2.0 and USNOB1.0 catalogs to detect any optical transients.
No new objects were found to the image limits. At 2.85 hrs after the burst, no afterglow was detected to R=18 (defined by images marked with stars on the following summary).
Summary of all observations:

                    total    image center   limiting  from
    mid UT        exposure  RA (J200.0) DEC  mag (R) burst(h) obs
-----------------------------------------------------------------
2003-09-13T18:56    20x10s  20 58 11 -02 17    15.5   1.83    OT 
2003-09-13T19:13     6x60s  20 58 38 -01 57    18.0   2.10    AO *
2003-09-13T19:21     6x60s  20 57 15 -02 00    18.0   2.23    AO *
2003-09-13T19:29     6x60s  20 58 44 -02 12    18.0   2.37    AO *
2003-09-13T19:37     6x60s  20 57 23 -02 14    18.0   2.50    AO *
2003-09-13T19:49     6x60s  20 59 01 -02 20    18.0   2.70    AO *
2003-09-13T19:58     6x60s  20 57 39 -02 22    18.0   2.85    AO *
2003-09-13T20:53     6x60s  20 58 49 -01 53    17.5   3.77    AO
2003-09-13T21:05     6x60s  20 57 11 -02 00    17.5   3.97    AO
2003-09-13T21:15     6x60s  20 58 45 -02 12    17.5   4.13    AO
2003-09-13T21:23     6x60s  20 57 21 -02 14    17.0   4.27    AO
2003-09-13T21:30    42x60s  20 57 49 -02 22    18.0   4.39    AT 
2003-09-13T21:31     6x60s  20 58 51 -02 26    17.5   4.40    AO
2003-09-13T21:39     6x60s  20 57 26 -02 29    17.5   4.53    AO
2003-09-13T22:26    10x45s  20 57 50 -02 14    18.0   5.32    CJ 
2003-09-13T22:38    10x45s  20 57 49 -01 59    18.0   5.52    CJ
2003-09-13T22:50    10x45s  20 57 55 -02 32    18.0   5.72    CJ
2003-09-13T23:38     6x45s  20 56 32 -02 17    17.5   6.52    CJ
2003-09-13T23:50     4x45s  20 56 29 -02 01    17.5   6.43    CJ
2003-09-14T00:24     4x45s  20 59 14 -02 14    17.5   7.28    CJ
2003-09-16T02:40    18x60s  20 58 02 -02 12    20.3  57.53    BG
2003-09-17T03:55    8x900s  20 58 06 -02 35    22.7  82.82    AH
-----------------------------------------------------------------

Observer details:
AO: Arto Oksanen, Finland FOV: 24 x 16 arc min Equipment: 0.40m SCT f/5.0, ST8XE CCD, Rc-filter
OT: Odd Trondal, Norway FOV: 20 x 15 arc min Equipment: 0.25 m f5.75, MX916 CCD, R-filter
CJ: Cristovao Jacques, Brazil FOV: 25 x 17 arc min Equipment: 0.30m SCT f/3.0 , ST7E CCD, unfiltered
BG: Bruce Gary, Arizona, U.S.A. FOV: 23 x 15 arc min Equipment: 0.35 m SCT, AO-7 stabilizer, ST-8XE CCD, unfiltered
AT: Andrea Tasselli, UK FOV: 16 x 22 arc min Equipment: 0.15 m Maksutov Cassegrain f/7, MX716 CCD
AH: Arne Henden, Arizona, U.S.A. FOV: 11 x 11 arcmin Equipment: 1.0m, CCD, R-filter
The AAVSO International High Energy network is grateful for a generous grant from the Curry Foundation and to NASA for the financial support for the High Energy Workshops for Amateur Astronomers.

GCN notice #2391
GRB 030913, possible optical counterpart
S. Guziy, A. de Ugarte Postigo,=20 A.J. Castro-Tirado, J.Gorosabel (IAA-CSIC/STScI),=20 P. Amado, Antonio Herrer=EDa (IAA-CSIC), Pilar Ruiz-Lapuente (Univ. Barcelona),=20 Javier M=E9ndez (ING, La Palma), J. M. Castro Cer=F3n (STScI), and A. Zurita (ING, La Palma)
report:
"On Sep 18.04 UT (4.25 days after the burst) we imaged 80%=20 of the HETE-II error box for GRB 030913 (Suzuki et al.,=20 GCNC 2383) with WHT at La Palma trough Johnson V filter.=20 We detected an uncatalogued point like source of=20 20.9 +/- 0.1 at the following coordinates +/- 2":
```
  RA(J2000) =3D 20:58:46.5
  DEC(J2000)=3D -02:20:59
```
On Sept 19.87 UT we imaged again the same field from the 1.5m telescope at Sierra Nevada Observatory (OSN, Granada) and detected an object at V mag =3D 23.6 +/- 0.5 on an equivalent position. Images of the field are posted on: http://www.iaa.es/~deugarte/GRBs/GRB030913/ Further images in R and B bands have been obtained that=20 confirm the detection. Other observations are encouraged=20 to confirm the relation of this object with GRB030913"
This message may be quoted.
GCN notice #2392
A. Henden (USRA/USNO) and A. Oksanen (Nyrola Obs.) report on behalf of the AAVSO International High Energy Network:
We have examined the early-time R-band images from Nyrola Observatory near the location of the proposed optical transient of Guziy et al. (GCN 2391). A stack of the f5.fit and f5b.fit composite images, giving an effective mid-exposure time of t_0 + 3.5hrs, does not convincingly show any object at the position shown in the Guziy et al. finding chart. A jpeg copy of the stack can be found at http://nyrola.jklsirius.fi/grb/grb030913/f5f5b.jpg Based on nearby USNO-B stars, we can place a limiting magnitude of R=19.5 for any object at this location. Combined with the V=20.9 at t_0 + 4.25day measure of Guziy et al., this would give an unrealistic decay slope for a typical GRB. Either this object is unrelated to the afterglow, or the afterglow increased in brightness after 4hrs.
The AAVSO International High Energy network is grateful for a generous grant from the Curry Foundation and to NASA for the financial support for the High Energy Workshops for Amateur Astronomers.
GCN notice #2394
V. Lipunov, A. Krylov, V. Kornilov, G. Borisov, D. Kuvshinov, A. Belinski, I. Chilingarian, M. Kuznetsov, S. Potanin, V. Vitrischak, G. Antipov Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow
report:
We have observed the error box of GRB030913 (Suzuki et al., GCNC 2383) with MASTER system (GCN 2385, http://observ.pereplet.ru) equipped with new AP16E CCD during the first night after the GRB. 25 frames, obtained during first 4 hours after the burst, were combined to achieve the better magnitude limit (the first image was obtained 43 minutes after GRB time).
No new sources were detected up to 17.5 unfiltered instrumental magnitude with S/N ratio of 3.
The part of processed frame is available at http://observ.pereplet.ru/images/grb030913OT.gif. North is up, east is left.
Position of possible OT, reported by Guziy et al. (GCN 2391) is marked on the image. No source brighter than 17.5 is seen there.
This message is citable.
GCN notice #2395
E. S. Rykoff and D. A. Smith, on behalf of the ROTSE collaboration report:
"The ROTSE-3c telescope at the H.E.S.S. site at Farm Goellschau, Namibia, responded automatically to HETE-2 alert 2849 (GRB 030913) on 13 September, and started taking images during early twilight within 7 s of the GCN notice distribution. Our first image with sky background low enough to perform photometric and astrometric calibration was taken at 17:38:14.11 UTC, 31 minutes after the burst, with observations continuing for another hour. All exposures were 60-s in duration. Initial analysis of the revised 12' error box reported by Donaghy, et. al (GCN 2388) revealed no new sources not present on the Digitized Sky Survey POSS2 red plate, and no sources that varied significantly over the duration of our observations, to an unfiltered limiting magnitude of 17.0 mag.
Co-adding our first set of ten usable images reveals no sources not present in the DSS to an unfiltered limiting magnitude of 19.2 mag. In particular, the proposed optical counterpart reported by Guziy et al. (GCN 2391) is not evident at t_0 + 36 min to this limiting magnitude."
GCN notice #2396
G. Kosugi, H. Furusawa, Y. Komiyama, K. Sekiguchi, M. Iye, and N. Kawai on behalf of the Subaru GRB team report:
We have observed the afterglow candidate of GRB 030913 (=H2849: GCN 2383, 2388) with the Subaru 8.2m telescope atop Mauna Kea on 2003 September 22.4 UT (9 days after the burst). A 600 sec V-band imaging observation was taken place with SuprimeCam (FOV: 24'x30') centered at the OT candidate reported by Guziy et al (GCN 2391). A galaxy (V = 23.0 +/- 0.2) was detected at the position of the OT candidate. We also detected a point-like source (V = 25.2 +/- 0.3) at about 1.5 arcsec north from the galaxy.
Images of the field center are posted on: http://www.naoj.org/staff/george/Distribute/GRB030913/GRB030913.html
This message may be cited.
UT 2003/09/22 08:55 V-Band image (600 sec exposure)

Magnified Image

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Jochen Greiner, last update: 23-Sep-2003 [Disclaimer]