//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2363 SUBJECT: GRB 030824: Candidate Afterglow (or Variable/Flare Star?) DATE: 03/08/25 09:59:50 GMT FROM: Jane Moran at U.North Carolina J. Moran, M. Nysewander, D. Reichart, P. Yim, C. Zdanowicz, and J. Reichart report on behalf of the UNC GRB team of the FUN GRB collaboration: We are currently observing the error region of GRB 030824 (HETE 2821) with the 0.6-meter Morehead Observatory telescope in R band through haze and fog. We detect a source that does not appear in DSS/POSS-II or 2MASS, at: RA: 00:04:36 DEC: 19:48:57 This source is near our detection limit, but is clearly visible in most of our individual frames, which now span many hours. We tentatively estimate its magnitude to be R ~ 17. We cannot rule out the possibility of a variable/flare star. A more detailed analysis will follow. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2364 SUBJECT: XRF030824: Palomar observations DATE: 03/08/25 10:42:29 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 WXM localization region for XRF030824 with the 200-inch Hale Telescope and Large-Format Camera on Mt. Palomar. Our dithered 4x300s images cover 95% of the 22.4'-diameter error circle at a mean epoch of August 25.25 UT, 0.55 days after the event. Visual comparison with the Digitized Sky Survey (POSS-II) reveals no new, bright sources within the localization region to the limiting magnitude of the GSC catalog, R~18.8. "The nearest star to the location of the candidate of Moran et al. (GCN 2363) has R~20.1 in our image." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2368 SUBJECT: XRF030824: optical observations DATE: 03/08/26 19:45:11 GMT FROM: Alexei Pozanenko at IKI, Moscow M.A. Ibrahimov, I.M. Asfandiyarov, B.B. Kahharov (UBAI), A.Pozanenko (IKI),V.Rumyantsev (CrAO), G.Beskin (SAO) report: We have observed the WXM error box of XRF030824 (HETE trigger 2821) with 1.5m telescope of Maidanak High-altitude Observatory (UBAI) on August 24. The 5x300s images taken between 21:19 and 21:51 UT (4.53hrs after the burst) cover 40% around the center of WXM error circle. The OT candidate (Moran et al. GCN 2363) is out of our coverage. Visual comparison with DSS2 reveals no new sources to the limiting magnitude R~19.5. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2369 SUBJECT: XRF030824: Second-epoch Palomar observations DATE: 03/08/27 05:13:18 GMT FROM: Derek Fox at CIT D.B. Fox and M.P. Hunt (Caltech), with P.A. Price (IfA/Hawaii) report on behalf of the Caltech-NRAO GRB Collaboration: "We have reobserved the HETE-2 WXM localization region for XRF030824 with the 200-inch Hale Telescope and Large-Format Camera on Mt. Palomar. Our dithered 4x300s images cover 95% of the 22.4'-diameter error circle at a mean epoch of August 26.42 UT, 1.72 days after the event. PSF-matched image subtraction of our first-epoch image (mean epoch Aug 25.25; Fox & Hunt, GCN 2364) does not reveal any bright, stationary, variable objects within the part of the WXM localization region covered by our images. The limiting magnitude of the individual images is approximately R~24.5. Within this region we set a lower limit of R>22.5 on the magnitude of any strongly variable optical counterpart to XRF030824 at either epoch. This is a conservative lower limit, which we consider appropriate given the size of the region. Separately, we note the presence of a slow-moving (15" per hour, PA=-73 deg) object within the error circle in our Aug 25.25 image, near RA 00:05:36.69, Dec +19:59:56.9 (J2000), with an approximate R-band magnitude of 19.9. The nearest star to the location of the object reported by Moran et al. (GCN 2363) is constant in brightness in our two images. We find no variable objects in the near vicinity; however, the location is only 15" from the borders of our imaged region. Observers interested in making their own investigation of these data, or comparing with other datasets, should contact Fox by email to arrange for data transfer." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2373 SUBJECT: GRB 030824: Candidate Follow-Up DATE: 03/08/31 23:42:32 GMT FROM: Melissa Nysewander at UNC,Chapel Hill M.C. Nysewander, J.C. Clemens, J.A. Moran and D.E. Reichart (University of North Carolina) report: Upon further inspection of the images of the candidate reported by Moran et al., GCN 2363, we find that the transient was the product of faulty hardware. Our new camera had not been fully tested by the time of the burst alert, and below spec CTE problems seemed to have caused the fading/variable source apparent in the images. We apologize for any confusion. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2379 SUBJECT: XRF030824: Optical observations DATE: 03/09/04 18:42:16 GMT FROM: Arto Oksanen at Nyrola Obs., Finland A. Oksanen on behalf of the Nyrola Observatory GRB Team and the AAVSO International High Energy Network reports: Total of five 24 x 16 arcmin fields covering most of the HETE WXM error circle of XRF030824 (HETE 2821) was imaged with the 0.4m SCT at the Nyrola Observatory starting at August 24, 2003 20:40 UT, 4.0 hours after the inital burst under varying sky conditions (some clouds and haze). Total of 22 240s Rc-exposures were combined and compared to the Digitized Sky Survey (DSS2R). No new objects were found to the image limits of R = 17.5 - 19.0. Field mid UT exposure limiting R mag ------------------------------------------------ XRF030824 20:50 5 x 240s 19.0 XRF030824NE 21:15 3 x 240s 18.5 XRF030824NW 21:35 5 x 240s 17.5 (clouds) XRF030824SE 22:01 5 x 240s 19.0 XRF030824SW 22:24 4 x 240s 19.0 ------------------------------------------------ The final combined images are available on the web with an image showing the error circle and the sky coverage of each field: http://nyrola.jklsirius.fi/grb/xrf030824/ 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2402 SUBJECT: XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM DATE: 03/09/25 04:11:45 GMT FROM: Don Lamb at U.Chicago M. Galassi, C. Graziani, Y. Shirasaki, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; T. Donaghy, E. Fenimore, M. Matsuoka, T. Sakamoto, M. Suzuki, T. Tamagawa, K. Torii, A. Yoshida, Y. Nakagawa, R. Satoh, Y. Urata, T. Yamazaki and Y. Yamamoto, on behalf of the HETE WXM Team; A. Dullighan, N. Butler, G. Crew, 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 16:47:35.10 UTC (60455.10 s UT) on 24 August 2003, the HETE FREGATE and WXM instruments detected event H2821, an X-Ray Flash. The burst triggered FREGATE in the 6-80 keV energy band. The WXM flight localization was correct, but was not sent to the GCN because the low fluence of the burst and its location at the edge of the WXM FOV did not meet the criteria for automatic propagation. Ground analysis of the WXM data provided a localization that was reported in a GCN Notice at 17:47:22 UT, 60 minutes after the burst. Further ground analysis of the WXM data provided a refined localization that was reported in a GCN Notice at 19:13:33 UT. The refined WXM ground localization SNR was 6. The refined WXM localization can be expressed as a 90% confidence circle, whose radius is 11.2 arcminutes and whose center is at: WXM-Ground: R.A. = +00h 05m 02s, Dec. = +19d 55' 37" (J2000). The SXC had not yet turned on because the burst occurred just before orbit dusk. The T90 duration for the burst was > 16 seconds in the WXM 2-25 keV energy band. The peak flux of the burst in 1 second is 5.4 x 10-8 erg cm-2 s-1 in the 7-30 kev energy band and 2.1 x 10-8 erg cm-2 s-1 in the 30-400 keV energy band. The fluence of the burst is 8.9 x 10-7 erg cm-2 and 5.8 x 10-7 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 XRF030824 is provided at the following URL: http://space.mit.edu/HETE/Bursts/GRB030824 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2406 SUBJECT: XRF 030824: observations at CFHT DATE: 03/10/05 11:57:54 GMT FROM: Michel Boer at CESR-CNRS A. Klotz, F. Malacrino, J.L. Atteia, M. Boer (CESR-LAT/OMP Toulouse), D. Fox, M.P. Hunt (Caltech), and C. Veillet (CFHT) communicate: We observed the error box of XRF 030824 (HETE 2821) with MEGAPRIME at the Canada-France-Hawaii Telescope, and i' filter, on September 21, 7h56 UT (two 300 sec exposures). This XRF has a relatively low "pseudo-z" (see Atteia, 2003, A&A, 407, L1), and we were looking for the possible rise of an associated type Ib,c supernova. Comparison with frames acquired at the 200-inch Hale Telescope and Large- Format Camera on Mt. Palomar (Fox and Hunt GCNC # 2364 and 2369) reveals two new objects at the following J2000.0 coordinates: Object 1: 0h05m12.30s, +20d06'29.4" +-0.2", i'=22.7+-0.2; no host galaxy detected. Object 2: 00h05m06.82s +20d05m00.4s +-0.4", i'=22.6+-0.4; offset from apparent host anonymous galaxy 0.56"W and 0.55"N, host magnitude i' = 21.5+-0.2 . While the objects are visible on both CFHT i' frames, they are not visible on Palomar images. No catalogued asteroid is associated with any object on the frames. Given the wide area scanned, these objects may be supernovae not associated with the GRB, or TNOs, or one of them can be associated with XRF 030824. Images and first analysis of the frames are available at the following URL: http://www.cesr.fr/~klotz/grb030824/cand.htm New observations are underway at CFHT. This message is citable //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2407 SUBJECT: XRF 030824: Early follow-up observation at Kiso observatory DATE: 03/10/06 06:37:06 GMT FROM: Yuji Urata at RIKEN Y. Urata, T. Soyano, T. Tamagawa on behalf of the Kiso GRB team, J. Jugaku (NAOJ), T. Kawamoto (Hokkaido University) report: "We have observed XRF030824 field (M. Galassi et al. GCN 2402) using the 105cm Schmidt telescope (Kiso Observatory, Institute of Astronomy, the University of Tokyo) and 2kx2k CCD camera with 2 degree objective prism from 76 to 153 min after the burst (from 16 min after HETE-2 alert). We have checked two candidates reported by Klotz et al (GCN 2406) comparing with Palomar images (Fox and Hunt GCN 2364 and 2369). We could not find these two candidates brighter than R~17 limited magnitude. We have also observed this field again at the end of September using the same instruments. Further analysis is in progress. These images can be found at http://cosmic.riken.go.jp/urata/XRF030824.gif (left image: Kiso 2D spectrum image, right image: Palomar image). We thank to Dr. D. Fox for suppling Palomar images." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2418 SUBJECT: XRF 030824: additional observations at CFHT DATE: 03/10/10 14:11:11 GMT FROM: Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse A. Klotz, F. Malacrino, J.L. Atteia, M. Boer (CESR-LAT/OMP Toulouse) communicate: Additonal observations of the field of XRF 030824 (HETE 2821) have been obtained with MEGAPRIME at the Canada-France-Hawaii Telescope. Two 800 sec exposures with i' filter, starting on Oct 3, 08:07 UT, and Two 300 sec exposures with r' filter, starting on Oct 4, 06:57 UT These data are being analyzed, in comparison with the data acquired with MEGAPRIME on Sept 21st (i' filter, Klotz et al., GCN 2406) and with the images of the Large Format Camera recorded on August 25 and 26th (R filter, Fox et al., GCN 2364 & 2369) A first result of these observations is to discard the two sources mentioned in GCN 2406 as being possibly associated with XRF 030824. These objects where selected as being significantly brighter in the September images than in the August images (as expected for a SN associated with XRF 030824). The new observations show that they are in fact very red objects, very faint in R but clearly visible in all i' images, and not variable. The whole set of observations is being re-analyzed to search for or to constrain a possible supernova associated with XRF 030824.