//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2360 SUBJECT: Lulin follow-up observations of GRB030823 DATE: 03/08/23 16:21:57 GMT FROM: Kuiyun Huang at IANCU K.Y Huang, Y. Urata, S. Takahashi, W.P. Chen , J.W. Chen, Y.S. Li, H.C. Lin, S.K. King and W.H. Ip report; "We have observed the entire error region of HETE-2 SXC of GRB030823(= H2818) with the Lulin observatory 1.0 m telescope starting at Aug. 23 12.406 UT. Muti-band images were taken by PI1300 camera (10'x 10' field of view). The limiting magnitude of R-band images taken with 60 sec exposure is 18.8 mag(SN=3, with USNO-A2.0 red magnitudes). Comparison with the DSS2 images, no new object was detected down to the limiting magnitude.The observation are in progress." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2361 SUBJECT: RAPTOR observations of GRB030823 DATE: 03/08/23 19:16:42 GMT FROM: James Wren at LANL J. Wren and W.T. Vestrand report on behalf of the RAPTOR team; Both telescope arrays of our RAPTOR stereoscopic sky monitoring system responded to the first HETE-2 ground notice for GRB030823 (2818). The first image was taken at 11:10:24.74 UT -- 4 seconds after receipt of the GCN notice and 2.3 hours after the burst itself. The initial images from RAPTOR-A reached an unfiltered limiting magnitude of 16.0. Comparison against our own archival frames and the USNO-A2.0 catalog within 10 arcminutes of the coordinates given in the second HETE ground notice (HETE 2818 seq. 4) yielded no candidate objects. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2362 SUBJECT: GRB030823: optical observation at Tokyo Tech DATE: 03/08/24 05:00:32 GMT FROM: Nobuyuki Kawai at Tokyo Tech M. Suzuki, Y. Yatsu, Y. Kuramoto, and N. Kawai report: "We have observed the field covering the entire SXC error box of GRB030823 (HETE trigger 2818; trigger time 08:52:40 UT) with the unfiltered CCD camera on the 30-cm telescope at Tokyo Tech, beginning at 10:43:19 UT. We started the observation earlier than the GCN notice, since M.S., as a member of the HETE ops team, had access to the preliminary WXM ground location before its validity was evaluated. Visual inspection of the images revealed no obvious new source compared with the DSS 2 (red) to an approximate limiting magnitude of 16.5." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2365 SUBJECT: GRB030823: Palomar observations DATE: 03/08/25 13:22:59 GMT FROM: Derek Fox at CIT D.B. Fox and M.P. Hunt (Caltech) report on behalf of the Caltech-NRAO GRB Collaboration: "We have observed the HETE-2 SXC localization region for GRB030823 with the 200-inch Hale Telescope and Large-Format Camera on Mt. Palomar on August 24.15 and August 25.23 UT. Our dithered 4x300s images cover the full localization region on each night at mean epochs of 0.78 and 1.86 days after the burst, respectively. PSF-matched image subtraction reveals no bright, variable sources within the SXC error box. We therefore derive a limit of R>22.5 on the brightness of any variable optical counterpart at the epoch of our first observation." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2366 SUBJECT: GRB030823: optical observations DATE: 03/08/25 19:53:38 GMT FROM: Alexei Pozanenko at IKI, Moscow M.A. Ibrahimov, I.M. Asfandiyarov, B.B. Kahharov (UBAI), A.Pozanenko (IKI), V.Rumyantsev, E.Pavlenko, O. Antoniuk (CrAO), G.Beskin (SAO) report: We have observed the entire SXC error box of GRB030823 (HETE trigger 2818) with different instruments. The observations started at 15:46 UT (6.9h after burst) with 1.5m telescope of Maidanak High-altitude Observatory (UBAI). Two sets of images (##1,2 in a table below) covering entire SXC error box at different epochs were taken with 1.5m telescope. Visual comparison of images at two different epochs reveals no bright variable source. Observations at Crimean Astrophysical Observatory were carried out with AT-64 and K-380 telescopes. Visual comparison of all images with DSS2 reveals no new sources down to limiting magnitude indicated in the table. # Mid. Time Telescope Exposure Limiting (UT) magnitude (R) 1 23.6651 1.5m (UBAI) 300s 19.5 2 23.7805 1.5m (UBAI) 300s 20.5 3 23.7826 AT-64 (CrAO) 7x180s 20.5 4 23.8131 K-380 (CrAO) 6x300s 19.0 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2370 SUBJECT: GRB 030823 observation at Ouda DATE: 03/08/28 11:35:23 GMT FROM: Taichi Kato at Kyoto U GRB 030823 observation at Ouda A. Imada, T. Kato (Kyoto U) and H. Yamaoka (Kyushu U) report: "We observed the entire SXC error circle of GRB (XRF) 030823 with Ouda 0.60-m telescope starting at Aug. 24.61 UT, i.e., 1.24 days after the burst. The limiting magnitude of a stacked Rc-band image (60 x 60 seconds exposure) is 20.5 mag, compared with USNO-A2.0 rmag. Visual comparison with the DSS 2 red image yields no new source." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2401 SUBJECT: XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC DATE: 03/09/25 03:55:45 GMT FROM: Don Lamb at U.Chicago Y. Shirasaki, G. Crew, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; T. Donaghy, C. Graziani, T. Tamagawa, M. Suzuki, M. Matsuoka, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, Y. Nakagawa, R. Satoh, Y. Urata, T. Yamazaki and Y. Yamamoto, on behalf of the HETE WXM Team; A. Dullighan, N. Butler, J. Doty, G. Prigozhin, R. Vanderspek, J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams; M. Boer, J-F Olive, J-P Dezalay, C. Barraud and K. Hurley on behalf of the HETE FREGATE Team; report: At 08:52:40.64 UTC (31960.64 s UT) on 23 August 2003, the HETE FREGATE, WXM, and SXC instruments detected event H2818, an X-Ray Flash. The burst triggered FREGATE in the 6-80 keV energy band. The burst occurred at the extreme edge of the FOV of the WXM Y-detector, and therefore no flight localization was possible. Ground analysis of the WXM data provided a localization that was reported in a GCN Notice at 11:10:20 UT. The WXM ground localization SNR was 19. The localization can be expressed as a 90% confidence rectangle, whose center is at: WXM-Ground: R.A. = 21h 30m 46s, Dec. = +21d 55' 43" (J2000), and whose corners lie at: R.A. = 21h 31m 02.6s, Dec. = 21d 37' 55" R.A. = 21h 30m 21.1s, Dec. = 21d 37' 23" R.A. = 21h 30m 29.0s, Dec. = 22d 13' 30" R.A. = 21h 31m 10.6s, Dec. = 22d 14' 02" (J2000). The SXC Y-camera detected the burst, but the X-camera did not. The SXC Y-camera localization further constrains the WXM location to an error box that was reported in a GCN Notice at 12:06:16 UT. This joint WXM/SXC localization can be expressed as a 90% confidence rectangle, whose center is at: SXC/WXM-Ground: R.A. = 21h 30m 47s, Dec. = +21d 59' 46" (J2000), and whose corners lie at: R.A. = 21h 30m 26.9s, Dec. = 22d 01' 44" R.A. = 21h 30m 25.9s, Dec. = 21d 57' 14" R.A. = 21h 31m 07.4s, Dec. = 22d 02' 17" R.A. = 21h 31m 06.5s, Dec. = 21d 57' 50" (J2000). The T90 duration of the burst was 56 seconds in the WXM 2-25 keV energy band. The peak flux of the burst in 1 second is 4.5 x 10-8 erg cm-2 s-1 in the 7-30 keV energy band and 5.5 x 10-8 erg cm-2 s-1 in the 30-400 keV energy band. The fluence of the burst is 2.3 x 10-6 erg cm-2 and 1.5 x 10-6 erg cm-2 in the same energy bands, respectively. Thus S(2-30 keV)/S(30-400 keV) = 1.5, making this burst an X-ray flash. A light curve and skymap for XRF030823 is provided at the following URL: http://space.mit.edu/HETE/Bursts/GRB030823