//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3347 SUBJECT: GRB (?) 050504: IR Observations, Intriguing Source DATE: 05/05/04 08:58:23 GMT FROM: Josh Bloom at Harvard/CFA J. S. Bloom (UCB) and J. X. Prochaska (UCSC): "In observing the field of Integral trigger 2486 with the PAIRITEL 1.3m we note a bright source near the center of the localization error circular. This source, at 13:24:03.027 +40:41:47 (J2000), is BD+41 2391 (=SAO 44596), is listed in the 2MASS catalogue with J=7.249, H=6.480 and Ks=6.289 mag and is of spectral type K2. Aside from the spatial coincidence, we have no other evidence connecting this source with the Integral trigger." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3348 SUBJECT: GRB 050504: A long GRB detected with INTEGRAL DATE: 05/05/04 09:13:04 GMT FROM: Sandro Mereghetti at IASF/CNR S. Mereghetti, D. Gotz (IASF, Milano), N. Mowlavi, S. Shaw, M. Beck, M. Turler (ISDC, Versoix) and J. Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: A long GRB has been detected by IBAS in IBIS/ISGRI data at 08:00:52.5 UT on May 4. Its coordinates (J2000) are: RA: 200.9986 [degrees] DEC: +40.6959 [degrees] with an uncertainty of 1.5 arcmin (90% c.l. radius). Note that this burst is located at high galactic latitude (b=+75 deg) and not affected by Galactic absorption. It is therefore a good target for optical follow-up searches. Analysis of the IBIS/ISGRI data yields a peak flux of 0.5 photons (6E-8 ergs)/cmsq/s (1 s integration time) and a fluence of 14.4 photons (1.5E-6 ergs)/cmsq (80 s integration time). Both values refer to the 20-200 keV energy range. The burst lasted about 80 s and had a FRED profile. A plot of the light curve can be found at: http://ibas.mi.iasf.cnr.it/IBAS_Results.html This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3349 SUBJECT: GRB050504: P60 Observations DATE: 05/05/04 09:35:00 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko and Derek B. Fox report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: We have imaged the error circle of GRB050504 (GCN 3348) with the automated Palomar 60-inch Telescope. Observations began at ~ 8:04 UT, 3 minutes after the burst. A coaddition of our first five Kron R band images (3 x 60 s, 2 x 120 s, mean epoch 8:14 UT), yields no new sources in the error circle compared with the Digital Sky Survey. Our limiting magnitude, calculated with respect to several Guide Star Catalog sources in the field, is approximately R > 21.0. We note, however, the bright source mentioned by Bloom & Prochaska (GCN 3347) affects our sensitivity over a significant fraction of the error circle. Further observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3351 SUBJECT: GRB050504: Faulkes North optical robotic limit DATE: 05/05/04 10:04:13 GMT FROM: Alessandro Monfardini at JMU/Liverpool Robotic Tele A. Monfardini, C. Guidorzi, I. Steele, C. Mottram, D. Carter, A. Gomboc, C. Mundell and M. Bode (Liverpool) on behalf of the ROBONET collaboration report: "The 2m Faulkes Telescope North on Haleakala automatically reacted to the INTEGRAL trigger for GRB050504 (GCN3348). The robotic pipeline, based on a series of short exposures, didn't detect any new source up to R ~ 19 at 3.7 minutes after the burst. The bright source mentioned in GCN3347 and GCN3349 by Cenko et al. affects our sensitivity over a significant fraction of the error circle too. Further observations are in progress." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3352 SUBJECT: GRB 050504, R band Observations DATE: 05/05/04 15:17:42 GMT FROM: Kuntal Mishra at ARIES,Nainital,India Kuntal Misra, S. B. Pandey (ARIES Naini Tal), on behalf of larger Indian GRB collaboration We monitored the INTEGRAL error-box (GCN 3348) of GRB 050504 using 1-m reflector at Naini Tal in R_c passband. In 300 sec exposure time, we did not reveal any new source up to ~ 20 mag, in comparison to the nearby USNO A2.0 star 1275-08249328. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3353 SUBJECT: Swift UVOT observation of GRB 050504 DATE: 05/05/04 18:50:47 GMT FROM: Massimiliano de Pasquale at MSSL-UCL M. De Pasquale (MSSL), A. Blustin (MSSL), A. Morgan (PSU), T. Poole (MSSL), M. Still (GSFC), N. Gehrels (GSFC), K. Mason (MSSL), J. Nousek (PSU), on behalf of the Swift UVOT team The Swift UVOT began observing the field of GRB 050504 (Mereghetti et al, GCN 3348) 5.45 hours after the trigger. We have co-added all UVOT V-band exposures of GRB 050504 taken between 13:27 UT and 13:45 UT, for a total exposure time of 989 seconds. No new source is detected within a 2 arcmin radius error circle around the position given by Mereghetti et al. We obtain a three sigma upper limit from the summed image of V=20.2. The magnitudes are based on preliminary zero-points, measured in orbit, and will require refinement with further calibration. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3354 SUBJECT: GRB 050504 : R band observation at Lulin observatory DATE: 05/05/04 19:18:08 GMT FROM: Kuiyun Huang at IANCU GRB 050504 : R band observation at Lulin observatory K. Sanchawala, Y.L. Wu, K.Y. Huang, W.H. Ip(NCU), Y. Urata, (RIKEN), Y. Qiu (BAO), Y.Q. Lou (THCA), on behalf of EAFON report: " We have imaged the error region of GRB 050504(GCN 3348) using 1-m telescope at Lulin Observatory, Taiwan. The R band observations ( 60s x 15 frames) started from 13.27 UT to 13.55 UT (~ 5.26 hours to 5.54 hours after the burst). The limiting magnitude of R band co-added image is R ~ 21 compared with USNOB1.0 stars. No new source was found down to the limiting magnitude. This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3359 SUBJECT: GRB 050504: Swift XRT position DATE: 05/05/05 17:31:15 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea, D. N. Burrows (PSU), K. Page, C. P. Hurkett (U. Leicester), B. Zhang (UNLV) and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: INTEGRAL detected GRB050504 at 08:00:52 UT on 4th May 2005 (GCN Circ 3348). The Swift observatory executed an Target of Opportunity observation of the INTEGRAL position and the XRT began taking data at 13:27:40 UT. In ground processing of 9218s of Photon Counting mode data we detect a faint uncataloged X-ray source located at: RA(J2000) = 13:24:01.3, Dec(J2000) = +40:42:12 We estimate an uncertainty of 6.9 arcseconds radius (90% containment). This position is 35 arcseconds from the INTEGRAL position reported in GCN 3348. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3426 SUBJECT: GRB 050504: Swift XRT afterglow candidate has faded DATE: 05/05/16 17:39:05 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea, D. N. Burrows (PSU), B. Zhang (UNLV) and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: Swift perfomed a follow up observation of the X-ray afterglow candidate of GRB050504 repored in GCN 3359. The new observation began on 01:38:23UT on 14th May 2005, and Swift-XRT collected 7 ks of photon counting mode data. Analysis of the ground processed data on GRB050504 from the second epoch observations reveal no detection of the source found in the first epoch. The 90% confidence level upper limit is 7.9 x 10^-4 cts/s compared to a source brightness in the first epoch of 3.5+/-0.7 x 10^-3 cts/s. We therefore conclude that the X-ray source reported in GCN 3359 has faded, and is most likely the X-ray afterglow of GRB050504. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3499 SUBJECT: GRB050504: Ashra-P2/3 monitor and Ashra-AFT response DATE: 05/05/28 14:38:57 GMT FROM: Koji Noda at ICRR,U of Tokyo M.Sasaki, N.Manago, Y.Aita, T.Aoki, Y.Asaoka, M.Jobashi, K.Noda, A.Okumura (ICRR, Univ.Tokyo), S.Ogawa (Toho Univ.), T.Chonan, Y.Watanabe (Titech) report on behalf of the Ashra collaboration: We have observed the field of GRB050504 (08:00:59 UT) covering the Integral error circle (Mereghetti et al, GCN 3348) by Ashra-P2/3 (Prototype of 2/3 scale) and Ashra-AFT at the Haleakala observatory in Hawaii (latitude = 20d 42' 37" N, longitude = 156d 15' 31" W, altitude = 3020m) in conditions of variable clouds across the field. The Ashra-P2/3 continuously monitored the Integral field with 5sec-repeat of unfiltered 4sec exposures from 1 second before the burst. The Ashra-AFT automatically responded to the Integral trigger and took the first image of 4sec-exposure at 08:01:57 UT (58 seconds after the burst and 37 seconds after the alert socket). We also took following 10 unfiltered images of 4sec-exposure every 9 to 10 seconds (08:01:57 UT - 08:03:29 UT). No new source was found within the Integral position by the two telescopes. We compared the co-added 10 images (10 x 4sec) from Ashra-P2/3 with BT in the Tycho catalog and the earliest 3 images and the co-added images (10 x 4sec) from Ashra-AFT with the USNO-B1.0 respectively. We preliminarily obtained 4-sigma limiting magnitudes as follows: Ashra-P2/3 limiting magnitude ----------------------------------------------------- start end exposure limit mag. after GRB (s) (s) BT ----------------------------------------------------- -1 49 40.0 8.0 ----------------------------------------------------- Ashra-AFT limiting magnitude ----------------------------------------------------- start end exposure limit mag. after GRB (s) (s) B1 R1 ----------------------------------------------------- 58 62 4.0 16.7 15.0 68 72 4.0 16.9 15.1 77 81 4.0 16.8 15.1 ----------------------------------------------------- 58 150 40.0 17.7 16.0 ----------------------------------------------------- URL: http://www.icrr.u-tokyo.ac.jp/~ashra/ This message can be cited.