This file contains BOTH 050502A and 050502B! //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3322 SUBJECT: GRB 050502: ROTSE-III Detection of Possible Counterpart DATE: 05/05/02 02:55:44 GMT FROM: Sarah Yost at U.Michigan S.A. Yost, H. Swan (U Mich), B. A. Schaefer (Louisiana State), K. Alatalo (U Mich) report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responsed to GRB 050502 (Integral trigger 2484) 23.3 s after the burst (5.0s after the GCN notice time), in conditions of variable clouds across the field. The unfiltered images are calibrated relative to USNO A2.0. Despite the changes in limiting magnitude due to the clouds, we see a 14.3rd magnitude, definitely fading source at: 13:29:46.3 +42:40:27.7 (J2000) The source is not visible in DSS (2nd epoch), 2MASS, or the MPChecker database. It is at ~14.3 mag, around 23.3 s after the burst in an image with a limiting magnitude of approximately 14.9. It is presently at ~ 18.5th mag, ~ 1000 sec post-burst. Continuing observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3323 SUBJECT: GRB 050502 - A long GRB detected with INTEGRAL DATE: 05/05/02 03:10:02 GMT FROM: Diego Gotz at IASF-CNR D. Gotz, S. Mereghetti (IASF, Milano), N. Mowlavi, S. Shaw, M. Beck (ISDC, Versoix) and J. Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: A 20 s long GRB has been detected by IBAS in IBIS/ISGRI data at 02:13:57 UT on May 2. Being at the beginning of a pointing the GRB may last longer. Its coordinates (J2000) are: RA: 202.4392 [degrees] DEC: +42.6741 [degrees] with an uncertainty of 2.0 arcmin (90% c.l. radius). Its preliminary peak flux (20-200 keV, 1s integration time) is about 1.3 ph (1E-07 erg)/cmsq/s. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3324 SUBJECT: GRB050502 - Optical Candidate from the Liverpool Telescope DATE: 05/05/02 03:27:49 GMT FROM: Andreja Gomboc at LT,ARI,Liverpool JMU A. Gomboc, I. A. Steele, A. Monfardini, C. J. Mottram, C. Guidorzi, M.F. Bode, C.G. Mundell (Liverpool JMU) report: The automatic pipeline of the Liverpool Telescope detected an optical transient at RA 13:39:46.25 dec +42:40:27.50. We measure the approximate magnitude r'~15.6 at ~3 min after the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3325 SUBJECT: GRB050502 - Correction on the Optical Candidate from the Liverpool DATE: 05/05/02 03:43:01 GMT FROM: Andreja Gomboc at LT,ARI,Liverpool JMU A. Gomboc, I. A. Steele, A. Monfardini, C. J. Mottram, C. Guidorzi, M.F. Bode, C.G. Mundell (Liverpool JMU) report: Due to a typing error, we need to correct the position of the transient of the GRB 050502 to be: RA 13:29:46.25 dec +42:40:27.50. We apologize for the inconvenience. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3326 SUBJECT: GRB 050502: PAIRITEL IR Observations DATE: 05/05/02 03:57:18 GMT FROM: Josh Bloom at Harvard/CFA J.S. Bloom (UCB) and C. Blake (Harvard) report on behalf of a larger collaboration: "The PAIRITEL 1.3m telescope began observations of GRB 050502 (GCN 3323) during twilight, approximately 31 minutes after the burst. We confirm a bright point source in our J,H,K images coincident with the location reported by Yost et al. (GCN 3322). This source is below the 2MASS detection limit. Observations and analysis are continuing." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3327 SUBJECT: GRB 050502: Confirmed variability of the afterglow candidate + DATE: 05/05/02 07:11:15 GMT FROM: Josh Bloom at Harvard/CFA C. Blake (Harvard) and J. S. Bloom (UCB) report: PAIRITEL has continued to image the Yost et al. optical candidate afterglow (GCN #3322). We confirm that the IR source (#3326) initially faded, strongly confirming the hypothesis from Yost et al. In particular, from T+47min to T+94 min the source faded by ~1.1 mag in J. But from T+94 min to T+121 min, there is some evidence for brightening by ~0.1 mag in J-band. A similar result is found in H and Ks. Based on an astrometric tie of 2MASS to a 141 sec J-band image from (start) 2005-05-02 02:52:40 UT, we find IRT: RA = 13:29:46.33, Dec = 42:40:27.3 --Offset to IRT-- A : RA = 13:29:42.78, Dec = 42:40:49.2 21.83" S, 39.19" E B: RA = 13:29:44.23, Dec = 42:38:13.1 134.20" N, 23.21" E The uncertainty in the absolute WCS is ~0.5 arcsec. Sources A and B are nearby bright sources suitable for blind offset spectroscopy." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3328 SUBJECT: GRB050502: ANU 1m optical Observations DATE: 05/05/02 10:04:50 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) Josh Rich, Brian Schmidt (Australian National University) and Jessie Christiansen (UNSW) report on behalf of a larger collaboration: "We observed a 5' region covering the BAT position of the SWIFT burst GRB 050502B(GCN#3237) using the ANU 1m telescope on May 2.40 UT in V band. Preliminary comparison with the DSS shows no OT to V=18. Further observations are continuing." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3329 SUBJECT: GRB 050502: INTEGRAL results DATE: 05/05/02 10:19:06 GMT FROM: Sandro Mereghetti at IASF/CNR D. Gotz and S. Mereghetti (IASF Milano) on behalf of the IBAS Localization Team report: Further analysis of the IBIS/ISGRI data for GRB 050502 (GCN Circ. n. 3323) indicates that the peak flux is 1.8 photons (2.E-07 ergs)/cmsq/s (1 s integration time) and the fluence is 14.7 photons (1.4E-6 ergs)/cmsq (21 s integration time). Both values refer to the 20-200 keV energy range. A plot of the light curve can be found at: http://ibas.mi.iasf.cnr.it/IBAS_Results.html Note that the data before 02:13:56 UT are missing in the plot because the satellite was performing a slew and that the short gap at 02:14:10 UT is due to satellite telemetry saturation. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3330 SUBJECT: Swift Detection of the Bright Burst GRB050502b DATE: 05/05/02 10:42:36 GMT FROM: David Burrows at PSU/Swift A. Falcone, D. N. Burrows, M. Chester (PSU), P. Schady (MSSL), J. Cummings (GSFC/NRC), D. Palmer (LANL), C. Pagani (PSU), B. Zhang (UNLV), K. Page, M. Goad (U.Leicester), N. Gehrels (GSFC) on behalf of the Swift Team. At 09:25:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB050502b (trigger=116116). The BAT on-board calculated location is RA, Dec = 142.543, +17.002 (09:30:10, +17:00:07) (J2000) with an uncertainty of 3 arcmin (radius, 3-sigma, including estimated systematic uncertainty). The BAT light curve showed a 7-second long peak with complex structure from t-4 to t+3. The maximum count rate was 4000 counts per second (15-350 keV) in the 1 second time interval centered around t+1. The spacecraft slewed promptly and the XRT began observations at 09:26:43 UT. The initial centroiding image detected only 5 counts, insufficient to produce a centroid. Further analysis will require the ground-processed data, which will be available at the Swift MOC at about 12:30 UT. The Swift Ultra Violet/Optical (UVOT) observations began at 09:26:40 UT, 60 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 135 sec after the BAT trigger. This image was sent directly to the ground via TDRSS with the FOV pixel binning set at 8 x 8 to reduce telemetry. A comparison against the USNO-B1 reveals a new source inside the BAT error circle at RA, Dec 09:30:12.58, +17:02:00.7 (J2000). This is 118 arcseconds from the BAT position. The V-band magnitude was 17.7 +/- 0.1. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3331 SUBJECT: GRB050502B: Optical Limits from ANU 1m DATE: 05/05/02 11:55:43 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) Joshua Rich, Brian Schmidt (Australian National University) and Jessie Christiansen (UNSW) report on behalf of a larger collaboration: Images taken with ANU 1m telescope show no source at the position of the SWIFT OT reported by Falcone et al. (GCN 3330) at the following (approximate) limits Band Time (UT) Age (Minutes) Limit V 9:35 9 V>19 V 9:48 22 V>21 I 9:58 32 I>20.5 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3332 SUBJECT: GRB 050502A: Redshift measurement based on Keck HIRES Observations DATE: 05/05/02 12:37:32 GMT FROM: Hsiao-Wen Chen at MIT/CSR Jason X. Prochaska (UCO/Lick Obs.), Sara Ellison (U. Victoria), R. J. Foley (UCB), J. S. Bloom (UCB), & H.-W. Chen (MIT) report on behalf of the GRAASP collaboration: "We observed the afterglow of GRB 050502a for 3600s with HIRES on the KeckI telescope starting at UT 05:53:46 on May 02, 2005, 3.5 hours after the initial burst. We obtained a low SNR, high resolution spectrum (R~40000). We report a tentative redshift of z=3.793 based on the following lines of evidence: 1. We detect a prominent flux discontinuity at 4400 Ang, blueward of which no flux is present. We interpret the flux decrement at 4400 A as the Lyman limit absorption produced by the host of the GRB. 2. The flux blueward of ~5870 Ang is 'patchy', i.e. indicative of the Lya forest. A broad absorption feature is present at 5820 Ang, which we interpret as the Lya absorption due to the ISM of the host galaxy. 3. We identify a strong absorption feature at 6040 Ang, which is consistent with SiII1260 at z=3.793. Further analysis is underway. This message can be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3333 SUBJECT: GRB 050502b: Swift XRT Position DATE: 05/05/02 12:53:52 GMT FROM: David Burrows at PSU/Swift C. Pagani, A. Falcone, D. N. Burrows, J. Kennea, S. Kobayashi (PSU), F. Marshall, and Neil Gehrels (GSFC) report on behalf of the Swift XRT team: The Swift XRT observed GRB 050502b (Falcone et al., GCN 3330) beginning at 09:26:43 UT. As reported in GCN 3330, the XRT obtained only 5 photons in its initial centroiding image and was not able to report a prompt centroid. Analysis of the first orbit of data reveals a bright, transient, uncataloged X-ray source at the following position: RA(J2000) = 09:30:10.1 Dec(J2000) = +16:59:44.3 The estimated uncertainty is 5 arcseconds radius (90% containment). We note that this position is 23.1 arcseconds from the BAT position reported in GCN 3330, and 141 arcseconds from the UVOT position reported in GCN 3330. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3334 SUBJECT: GRB 050502b : optical observation at Lulin observatory DATE: 05/05/02 15:47:37 GMT FROM: Yuji Urata at RIKEN K. Sanchawala, W.L. Wu, K.Y. Huang, W.H. Ip(NCU), Y. Qiu, W. Zhou (BAO), Y.Q. Lou (THCA), Y. Urata (RIKEN) on behalf of the EAFON report: " We have imaged the Swift XRT position of GRB 050502b (Pagani. C. et al., GCN 3333) using 1-m telescope at Lulin Observatory, Taiwan. The R band observations started from 13.45 UT (~ 3.98 hours after the burst). The limiting magnitude of R-band co-added image is R~21.8 compared with USNO-B1.0 stars. No source was detected under the limiting magnitude at the XRT position." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3335 SUBJECT: GRB 050502a : R band observation at Lulin observatory DATE: 05/05/02 16:49:12 GMT FROM: Yuji Urata at RIKEN K. Sanchawala, W.L. Wu, K.Y. Huang, W.H. Ip(NCU), Y. Qiu, W. Zhou (BAO), Y.Q. Lou (THCA), Y. Urata (RIKEN), on behalf of EAFON report: " We have observed the position of GRB 050502a optical afterglow (Yost et al. GCN 3322) using 1-m telescope at Lulin Observatory, Taiwan. Under unstable weather condition, single R band image was taken at 15.59 UT (~ 13.37 hours after the burst). The limiting magnitude is R~ 21 compared with USNO-B1.0 stars. No source was detected down to the limiting magnitude at the position. This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3337 SUBJECT: Swift UVOT refined analysis DATE: 05/05/02 22:32:34 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL), A. Falcone (PSU), S. Holland (GSFC/NRC), S. Koch (PSU), A. Breeveld, K. Mason (MSSL), J. Nousek (PSU), N. Gehrels (GSFC) on behalf of the UVOT Swift team On further analysis of the Swift UVOT data, the afterglow candidate reported in GCN 3330 (Falcone et al.) is not observed in the 1 x 1 binned first 100 sec exposure taken in the V filter. Starting with data taken ~192s after the BAT trigger (Falcone et al., GCN 3330) we have co-added the early time data of GRB 050502b in each of the UVOT V, B and U bands. The co-added images are made up of 9 x 10s exposures. No source is detected at the position of the afterglow candidate reported in GCN 3330 (Falcone et al.) or within the XRT error circle (Pagani et al., GCN 3333) in any of the bands. We estimate the five sigma magnitude upper limits from the co-added images to be: Filter Upper limit V 18.5 B 19.4 U 19.2 The magnitudes are based on preliminary zero-points, measured in orbit, and will require refinement with further calibration. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3338 SUBJECT: GRB050502B: I band source in XRT error circle DATE: 05/05/03 00:04:58 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) Joshua Rich, Brian Schmidt (Australian National University) and Jessie Christiansen (UNSW) report on behalf of a larger collaboration: Images taken with ANU 1m telescope show a source within the SWIFT XRT error circle (Pagani et al., GCN 3333) at I=19.5 located at RA=09:30:10.024 DEC=+16:59:48.07 J2000. This object does not vary by more than +/- 0.1 mag from 2 May 2005 UT 9:58 through to UT 11:05. The object is not detected in V to V>21. The object is 4.01+/-0.1 mag fainter than the star located at RA=09:30:12.616 DEC=+17:00:05.55 in I. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3339 SUBJECT: GRB050502B Swift-BAT refined analysis DATE: 05/05/03 01:15:39 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. Cummings (GSFC/NRC), L. Barbier (GSFC), S. Barthelmy (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), M. Tashiro (Saitama U.), J. Tueller (GSFC), on behalf of the Swift/BAT team: At 09:25:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB050502B (trigger=116116) (GCN Circ 3330, Falcone et al.). The refined BAT ground position is (RA,Dec) = 142.543, +17.002, [deg; J2000] +- 3 arcmin, (95% containment). This is 24 arc seconds from the position determined by the XRT (GCN Circ 3333, Pagani, et al.). The burst was 10 degrees off the Swift boresight, within the fully-coded BAT field of view. The BAT mask-weighted light curve shows one main peak of about 6 seconds duration centered at the trigger time preceded by two smaller peaks 16 and 10 seconds earlier with a softer spectrum. T90 (15-350 keV) is (17.5 +- 0.2) seconds (estimated error including systematics). The spectrum is well fit by a single power law with photon index of 1.6 +- 0.1. The fluence in the 15-350 keV band is (8.0 +- 1.0) x 10^-7 erg/cm2. The peak photon flux in the 15-350 band is (1.73 +- 0.15) ph/cm2/s. All the quoted errors are at the 90% confidence level. We note that this burst appears to be well-suited for ground follow-up observations, as it is located 90 degrees from the Sun, 180 degrees from the Moon, close to the ecliptic, and away from the Galactic center. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3340 SUBJECT: GRB050502A: Optical Observations DATE: 05/05/03 02:42:36 GMT FROM: Aaron Price at AAVSO D.T. Durig (Cordell-Lorenz Observatory - The University of The South) reports on behalf of the AAVSO International High Energy Network on optical observations of GRB050502A (GCN #3323, Gotz et al.): Durig reports the following rapidly fading behavior: Date (UT) Mag 02.17880 19.8 02.18243 20.8 02.18606 20.3 02.18969 20.4 02.19331 20.5 02.19694 20.9 02.20056 21.4 02.20418 21.4 02.20781 21.0 02.21144 21.3 Observations were made unfiltered based on a V zeropoint. Uncertainly is +/- 0.4 magnitudes. Details of the observation are below along with a link to the co-added FITS image. Full Observation Details Name: Dr. Douglas T. Durig email: ddurig@sewanee.edu Observer: D. T. Durig ( CLW01) Site: Cordell-Lorenz Observatory Location: Sewanee, TN, USA LatitudeLongitude: 35 12 N 85 55 W Elevation: 600 m Scope: SCT 0.30 m ScopeFocalRatio: f/5.8 1766 mm FL CCDVendor: SBIG ST1001E CCDDetector: KAF1001E CCDSize: 1024x1024 CCDPixelScale: 2.8 arc sec/ pixel CCDFOV: 48x48 full, 12x12 cropped submitted Object: GRB050502 ObsDate: 2005 05 02 ObsMidPointTime: 2.15912 (04 40 58 UT ) TimePerFrame: 300 sec NumberOfFrames: 11 Filters: CV Processing: dark, flat, registered, added, quarter frame cropped Seeing: 4 to 5 arc sec LimitingMag (SNR=3): 21.0 ??? Sky: very clear afterglowmag: 20 fading to 21 during first hour afterglowerr: 0.4 compstars: 900 USNO B1.0 stars Report: I could see the afterglow candidate in my first few images but it was fading fast and I had to stack to see it well in later images. Ave Position:13 29 46.28 +42 40 27.7 I get the following magnitudes for co-added (10min) frames: 02.17880 19.8 CV 02.18243 20.8 CV 02.18606 20.3 CV 02.18969 20.4 CV 02.19331 20.5 CV 02.19694 20.9 CV 02.20056 21.4 CV 02.20418 21.4 CV 02.20781 21.0 CV 02.21144 21.3 CV A FITS image has been uploaded to ftp://ftp.aavso.org/grb/Dr.DouglasT.Durig_GRB050502_2453492.77287_.fits The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3341 SUBJECT: GRB 050502A: WSRT Radio Observations DATE: 05/05/03 12:36:59 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst, R.A.M.J. Wijers and K. Wiersema (University of Amsterdam) report on behalf of a larger collaboration: "We observed the position of the GRB 050502A afterglow at 1.4 and 4.9 GHz with the Westerbork Synthesis Radio Telescope at May 2 16.33 UT to May 3 4.31 UT, i.e. 14.10 - 26.08 hours after the burst (GCN 3323). We do not detect a radio source at the position of the optical afterglow (GCN 3322). The formal flux measurements for a point source at the location of the optical afterglow is 0 +/- 28 microJy at 1.4 GHz, and -69 +/- 29 microJy at 4.9 GHz." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3342 SUBJECT: GRB 050502a: RBO Observations DATE: 05/05/03 15:03:37 GMT FROM: Melissa Nysewander at UNC,Chapel Hill D. Allen, J. Silvey and R. Canterna report on behalf of the RBO Team of the FUN GRB Collaboration: We observed the position of the afterglow of GRB 050502a (Yost et al., GCN 3322; Gotz et al., GCN 3323) with the Red Buttes Observatory 24-inch telescope under high humidity and non photometric conditions. We do not detect the afterglow down to the following values: UT Start Time Filter Limiting Since GRB (hr) Magnitude 08:04 5.83 R 19.1 09:08 6.90 R 20.1 09:19 7.08 I 18.3 10:40 8.43 I 19.0 10-sigma limiting magnitudes were derived from the USNO-B1.0 catalogue. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3344 SUBJECT: GRB050502a: P60 Observations DATE: 05/05/03 21:02:27 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 field of GRB050502a (GCN 3323) with the automated Palomar 60-inch Telescope. Observations consisted of 30 x 120 s exposures in the Kron R band. We detect no emission at the position of the afterglow reported by Yost et. al. (GCN 3322). Our 3-sigma limiting magnitude, estimated by comparison with several Guide Star Catalog sources in the field, is approximately R > 21.5. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3345 SUBJECT: GRB050502a: P60 Observations (Correction) DATE: 05/05/03 21:37:41 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 field of GRB050502a (GCN 3323) with the automated Palomar 60-inch Telescope. Observations consisted of 30 x 120 s exposures in the Kron R band, taken at a mean epoch of 9:30 May 3 UT (~ 30.3 hours after the burst). We detect no emission at the location of the afterglow reported by Yost et. al. (GCN 3322). Our limiting magnitude, estimated by comparison with several Guide Star Catalog sources in the field, is approximately R > 21.5. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3346 SUBJECT: GRB 050502b, Optical observations DATE: 05/05/04 06:49:22 GMT FROM: T.P. Prabhu at Indian Astro. Obs. The field of GRB 050502b (GCN 3330, 3333) was observed by B.C. Bhatt, S. Ramya and G.C. Anupama on 2005 May 2, 14:45 UT, using the 2-m Himalayan Chandra Telescope, Indian Astronomical Observatory, Hanle. The co-added 40 min (4 x 600s) R frame does not show any optical transient down to R ~ 22.5 mag. This message may be quoted in publications. -- T.P. Prabhu, on behalf of the GRB followup team of Indian Astronomical Observatory, Hanle //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3350 SUBJECT: GRB 050502b, V band Observations DATE: 05/05/04 09:49:37 GMT FROM: Kuntal Mishra at ARIES,Nainital,India Kuntal Misra, S. B. Pandey (ARIES Naini Tal), on behalf of larger Indian GRB collaboration We observed the SWIFT burst (trigger = 116116) using 1-m Sampurnanand Telescope at ARIES, Naini Tal. The observations were carried out in V band (12*300sec). In the combined V band image (around May 02.654 UT, mean epoch of observations), we did not reveal any new source down to ~ 21.5 mag, in comparison to a nearby star 09:30:06.62 +16:58:59.0 (V mag 15.992). This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3357 SUBJECT: GRB050502b: Afterglow Confirmation DATE: 05/05/05 06:25:50 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko, Derek B. Fox (Caltech), Joshua Rich, Brian Schmidt (ANU), Jessie Christiansen (UNSW), and Edo Berger (Carnegie) report: We have further analyzed our images of the field of GRB050502b (GCN 3330) taken with the 1-m ANU telescope (GCN 3338). Additionally, we have imaged the field with the automated Palomar 60-inch telescope (P60). Observations at the P60 consisted of 10 x 120 s exposures in the Gunn i band taken at a mean epoch of 5:40 4 May 2005 UT (43.8 hours after the burst). Based on extrapolations from the 2MASS and USNO-B2 catalogs, we adopt values of V=16.7, I=15.8, R=16.1 for the star located at RA = 09:30:12.616, Dec = +17:00:05.55 (J2000.0). We find the magnitude of the afterglow candidate identified by Rich, Schmidt, and Christiansen (GCN 3338) as follows: Filter Facility UT Age Limit (3-sig) or measure ======================================================== V ANU1m 9:35 May 2 9.5 min V>20.7 V ANU1m 9:41 May 2 15 min V>20.2 V ANU1m 9:43 May 2 18 min V>20.8 V ANU1m 9:46 May 2 20 min V>21.8 I ANU1m 9:58 May 2 23 min I=19.84+/-0.09 i P60 5:40 May 4 43.8 hr i>21.7 We therefore identify this source as the afterglow of GRB050502b. To reiterate the coordinates (J2000.0): RA: 09:30:10.024 Dec: +17:00:05.55 Finally, we note the spectral slope at early times, beta > 2.9, indicates that GRB050502b may be either highly extinguished or at moderately high redshift. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3358 SUBJECT: GRB050502b: Afterglow Confirmation: Correction to OT Coordinates DATE: 05/05/05 10:38:37 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) S. Bradley Cenko, Derek B. Fox (Caltech), Joshua Rich, Brian Schmidt (ANU), Jessie Christiansen (UNSW), and Edo Berger (Carnegie) report: We have further analyzed our images of the field of GRB050502b (GCN 3330) taken with the 1-m ANU telescope (GCN 3338). Additionally, we have imaged the field with the automated Palomar 60-inch telescope (P60). Observations at the P60 consisted of 10 x 120 s exposures in the Gunn i band taken at a mean epoch of 5:40 4 May 2005 UT (43.8 hours after the burst). Based on extrapolations from the 2MASS and USNO-B2 catalogs, we adopt values of V=16.7, I=15.8, R=16.1 for the star located at RA = 09:30:12.616, Dec = +17:00:05.55 (J2000.0). We find the magnitude of the afterglow candidate identified by Rich, Schmidt, and Christiansen (GCN 3338) as follows: Filter Facility UT Age Limit (3-sig) or measure ======================================================== V ANU1m 9:35 May 2 9.5 min V>20.7 V ANU1m 9:41 May 2 15 min V>20.2 V ANU1m 9:43 May 2 18 min V>20.8 V ANU1m 9:46 May 2 20 min V>21.8 I ANU1m 9:58 May 2 23 min I=19.84+/-0.09 i P60 5:40 May 4 43.8 hr i>21.7 We therefore identify this source as the afterglow of GRB050502b. To reiterate the coordinates (J2000.0): RA 09:30:10.024 DEC +16:59:48.07 Finally, we note the spectral slope at early times, beta > 2.9, indicates that GRB050502b may be either highly extinguished or at moderately high redshift. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3363 SUBJECT: GRB 050502a: Optical Observations DATE: 05/05/06 01:03:13 GMT FROM: Nestor Mirabal at U Michigan N. Mirabal (U. Michigan), M. Boettcher, J. Shields, M. Joshi (Ohio U.), and J. P. Halpern (Columbia U.) report on behalf of the MDM GRB follow-up team: "We monitored the optical afterglow (Yost et al., GCN #3322) of GRB 050502a with the MDM 1.3m telescope beginning on 2005 May 2.163 UT and spanning from 1.8 hr to 8.2 hr after the burst. Preliminary photometry referenced to a USNO-B1.0 star at (J2000) R.A. 13:29:59.84, Decl. +42:43:00.2 listed as R = 16.01, indicates that the OT faded from approximately R~19.3 on May 2.163 to R~21.4 on May 2.36, and continued to decline until the end of the monitoring period. The corresponding power-law decay index is -1.44 +/- 0.2. This is steeper than the decay index of -1.03 estimated from the earlier observations of Yost et al. (GCN #3322)." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3355 SUBJECT: GRB050502: P200 Observations DATE: 05/05/05 00:14:01 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko, Derek B. Fox, and P. Brian Cameron report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: We have imaged the field of GRB050502 (GCN 3323) with the Large Format Camera (LFC) mounted on the Palomar 5-m Hale Telescope. Observations consisted of 2 x 600 s exposures in the Sloan r' filter. At a mean epoch of ~ 11:30 4 May 2005 UT (57.3 hours after the burst), we find no emission at the afterglow position reported by Yost et al. (GCN 3322). Our 3-sigma limiting magnitude, calculated by comparison with several Guide Star Catalog sources in the field, is approximately r' > 23.5. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3356 SUBJECT: GRB050502: P200 Observations (Correction) DATE: 05/05/05 00:39:15 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko, Derek B. Fox, and P. Brian Cameron report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: We have imaged the field of GRB050502 (GCN 3323) with the Large Format Camera (LFC) mounted on the Palomar 5-m Hale Telescope. Observations consisted of 2 x 600 s exposures in the Sloan r' filter. At a mean epoch of ~ 11:30 3 May UT (33.3 hours after the burst), we find no emission at the afterglow position reported by Yost et al. (GCN 3322). OUr 3-sigma limiting magnitude, calculated by comparison with several Guide Star Catalog sources in the field, is approximately r' > 23.5 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3374 SUBJECT: GRB 050502a: Swift XRT Upper Limit DATE: 05/05/06 20:50:21 GMT FROM: Cheryl Pauline Hurkett at Leicester U C. Hurkett, K.Page, J. P. Osborne (U Leicester), B. Zhang (UNLV), J. Kennea, D. N. Burrows (PSU) and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: The Swift XRT observed the INTEGRAL burst GRB 050502a for ~2.5ks from 13:17 UT to 18:42 UT on 02 May 2005; for ~2.5 ks from 15:00 UT to 20:01 UT on 03 May 2005 and for ~43 ks from 00:28 on 04 May 2005 to 23:10 on 05 May 2005. In the first observation (02 May 2005) we detect no source in a 20 arcsec radius circle centred at the position of the optical counterpart identified by Yost et al 2005 (GCN 3322), with a 90% confidence upper limit of 1.03e-3 counts/s (0.2 - 10.0 keV). Combining data from all three observations, we obtain 35.5 ks of good data after normal data screening. We still detect no source in a 20 arcsec radius circle centred at this position, with a 90% confidence upper limit of 1.8e-4 counts/s (0.2 - 10.0 keV). Assuming a Crab-like spectrum, this corresponds to 7e-15 ergs/cm2/s (0.5 - 10.0 keV). Compared to other Swift XRT afterglows, GRB 050502a is unusually faint at these times. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3421 SUBJECT: GRB050502b: Early Observation DATE: 05/05/13 13:59:21 GMT FROM: Koji Noda at ICRR,U of Tokyo M. Sasaki, N. Manago, K. Noda, Y. Asaoka report on behalf of the Ashra collaboration: We have observed the field of GRB050502b (09:25:40 UT) covering the SWIFT XRT error circle (Pagani et al., GCN 3333) by the Ashra-AFT (Automated Follow-up for Transients) telescope at the Haleakala observatory in Hawaii (latitude = 20d 42' 37" N, longitude = 156d 15' 31" W, altitude = 3020m). The telescope (12" Meade LX200GPS with a KAI-2020M CCD) is served as a follow-up detector to quickly respond to triggers from Ashra optical transient survey monitor as well as from GRB satellites. The telescope automatically slewed to the GRB and took the first image of 1.4sec-exposure at 09:26:36 UT (56 seconds after the burst and 32 seconds after the BAT alert socket). We also took following 363 images of 4sec-exposure every 9 to 10 seconds (09:26:36 UT - 10:25:47 UT). These images are unfiltered to maximize the detection sensitivity, of which peak is between B and V. No new source was found within the SWIFT XRT position. From the earliest 4 images and the co-added images (3 x 4sec, 25 x 4sec), we preliminarily obtained 4-sigma limiting magnitudes of B1 and R1 in the USNO-B1.0 catalog as follows. ----------------------------------------------------- start end exposure limit mag. after GRB (s) (s) B1 R1 ----------------------------------------------------- 56.0 57.4 1.4 16.2 14.6 66.0 70.0 4.0 16.9 15.5 76.0 80.0 4.0 16.2 14.6 85.0 89.0 4.0 16.2 14.6 ----------------------------------------------------- 66.0 89.0 12.0 17.2 16.2 66.0 294.0 100.0 18.5 17.0 ----------------------------------------------------- URL: http://www.icrr.u-tokyo.ac.jp/~ashra/GRB050502b/ This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4113 SUBJECT: GRB 050502b: Optical limit DATE: 05/10/19 04:41:38 GMT FROM: Ken ichi Torii at RIKEN K. Torii (Osaka U.) reports on behalf of the ART collaboration: The error region of the bright GRB 050502b (Falcone et al. GCN 3330) was observed by the 14 inch Automated Response Telescope. Ic band imaging was started at 2005 May 2 10:19:30 UT (54 minutes after the burst) and 60s exposure was repeated. The optical afterglow (Rich et al. GCN 3338) is not detected in our frames and the following 3-sigma upper limit is derived for a stacked image. ------------------------------------------ StartUT-EndUT Filter Limit Exposure ------------------------------------------ 10:55:59-13:00:20 Ic >18.6 87x60s ------------------------------------------