//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11957 SUBJECT: GRB 110422A: Swift detection of a burst DATE: 11/04/22 16:04:43 GMT FROM: Vanessa Mangano at INAF-IASFPA V. Mangano (INAF-IASFPA), D. N. Burrows (PSU), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), B. Gendre (ASDC), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU) and C. A. Swenson (PSU) report on behalf of the Swift Team: At 15:41:55 UT, the Swift Burst Alert Telescope (BAT) triggered and located the bright GRB 110422A (trigger=451901). Swift slewed to the burst after a 12 minute observing constraint delay. The BAT on-board calculated location is RA, Dec 111.995, +75.106 which is RA(J2000) = 07h 27m 59s Dec(J2000) = +75d 06' 21" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex peak structure with a duration of about 50 sec. The peak count rate was ~24000 counts/sec (15-350 keV), at ~8 sec after the trigger. The XRT began observing the field at 15:55:30.4 UT, 814.5 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 112.0580, +75.1077 which is equivalent to: RA(J2000) = 07h 28m 13.92s Dec(J2000) = +75d 06' 27.7" with an uncertainty of 6.1 arcseconds (radius, 90% containment). This location is 58 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 821 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. Burst Advocate for this burst is V. Mangano (vanessa AT ifc.inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11958 SUBJECT: GRB 110422A: Mondy optical observations DATE: 11/04/22 17:25:29 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Klunko (ISTP), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We started observation of the field of GRB 110422A (Mangano et al. GCN 11957) with AZT-33IK on Apr. 22 (UT) 15:58. We detected new object, not presented in DSS2 in coordinates (J2000) 07 28 10.972 +75 06 24.87 with statistical uncertainty of 1" in booth coordinates. The object is close to the current XRT position. The first image was unfiltered, while after detection we started several series in R-filter. The brightness of the object in the first image taken 16 min after burst onset is R=18.3 in comparison with nearby USNOB-1.0 field stars. We suggest that the object is the afterglow of GRB 110422A. The finding chart can be found at http://grb.rssi.ru/GRB110422A/grb110422A_AZT33IK.png Observation is continuing. [GCN OPS NOTE(23apr11): Per author's request, Elunko was changed to Klunko.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11959 SUBJECT: GRB 110422A: Swift-BAT refined analysis DATE: 11/04/22 18:14:12 GMT FROM: Scott Barthelmy at NASA/GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), V. Mangano (INAF-IASFPA), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+195 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110422A (trigger #451901) (Mangano, et al., GCN Circ. 11957). The BAT ground-calculated position is RA, Dec = 112.057, 75.100 deg, which is RA(J2000) = 07h 28m 13.7s Dec(J2000) = +75d 05' 58.8" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 22%. The mask-weighted light curve shows several overlapping peaks starting at ~T-15 sec, peaking at ~T+8 sec, and ending at ~T+60 sec. At the 3-sigma level, there is another peak from T+70 to T+115 sec. T90 (15-350 keV) is 25.9 +- 0.6 sec (estimated error including systematics). The time-averaged spectrum from T-11.2 to T+40.3 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.86 +- 0.10, and Epeak of 149.4 +- 18.5 keV (chi squared 46.5 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.1 +- 0.1 x 10^-5 erg/cm2 and the 1-sec peak flux measured from T+6.90 sec in the 15-150 keV band is 30.7 +- 1.0 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.35 +- 0.00 (chi squared 118.3 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/451901/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11960 SUBJECT: GRB 110422A: MASTER earlier OT polarization observations DATE: 11/04/22 21:09:53 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs O. Gres, K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Chuvalaev Irkutsk State University E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov Ural State University, Kourovka V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka (Baykal lake) was pointed to the GRB 110422A 34 sec after notice time and 53 sec after GRB time at 2011-04-22 15:42:48.507 UT. On our first (10s exposure) double set we found optical transient within SWIFT error-box (Palmer et al.11959). The position coincided with Elunko et al. GCN 11958. The polarizated magnitude in R band is ~16.5+-0.4 . We see OT on all next images in both polarizations. Is seems some brightenning during first minutes. The reduction is continuated. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11961 SUBJECT: GRB 110422A: NOT optical observation DATE: 11/04/22 22:19:20 GMT FROM: Dong Xu at Weizmann Inst Dong Xu (WIS), Anders Thygesen, Fatemeh Kiaee (NOT), and Pall Jakobsson (U. Iceland) report on behalf of a large collaboration: We observed the field of GRB 110422A (Mangano et al., GCN 11957) at the Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 2x300 s R-band images with a median time 21:11:33.3 UT (i.e., 5.49397 hr after the BAT trigger). The images, with an airmass ~1.5, were taken under the windy condition. A new optical source is detected at coordinates (RA,Dec)(J2000.0) = (07:28:11.06, +75:06:25.00) (error-radius: ~ 0.1 arcsec), being consistent with the finding in Elunko et al. (GCN 11958) and Gres et al. (GCN 11960). Note that this position is southwest of and outside the XRT error circle reported at http://www.swift.ac.uk/sper/. The source has R~20.0 mag, calibrated with the #1651-0050630 star (R1=19.08) in the USNO B1 catalog. Further observation is planned as long as the weather could stay observable at La Palma. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11962 SUBJECT: GRB 110422A: SAO RAS optical observations DATE: 11/04/22 23:53:33 GMT FROM: Vladimir Sokolov at SAO RAS A. S. Moskvitin (SAO RAS, Niznijh Arkhyz, Russia), report: The field of GRB 110422A (Mangano et al., GCN 11957) were observed with the Zeiss-1000 telescope of SAO RAS, Russia. The observations were carried out in the B and Rc bands at 18:39:11 -- 19:00:08 UT, April, 22 (~3 hours after the trigger). The magnitude of OT (Elunko et al. GCN 11958, Gres et al. GCN 11960 and Xu et al. GCN 11961) were measured as R = 19.13 +/- 0.13 in comparison with nearby USNO-B1.0 stars (R2 magnitudes). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11963 SUBJECT: GRB 110422A: TNG optical observations DATE: 11/04/23 00:25:49 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri, P. D'avanzo, D. Fugazza (INAF-OAB) and E. Palazzi (INAF-IASFBo) on behalf of a larger collaboration report: We observed the field of GRB 110422A (Mangano et al. GCN 11957) with the 3.6m TNG equipped with the Dolores camera. Few sets of unfiltered images were acquired starting on Apr 22.89 UT (i.e. ~5.7 hours after the burst event). The optical afterglow (Elunko et al. GCN 11958; Gres et al. GCN 11960; Xu et al. GCN 11961, Moskvitin GCN 11962) is clearly detected in all our frames. The observed magnitudes (calibrated with respect to the same star used in GCN 11961) are Dt_start t_exp R_mag err [hr] [s] --------------------------------------------- 5.777 60.0 20.17 0.03 5.934 60.0 20.24 0.05 5.998 60.0 20.03 0.05 8.052 60.0 20.24 0.04 Our observations, coupled with previous observations reported on GCNs imply a power-law decay index for the optical afterglow of ~0.55. Further observations are ongoing. We thank the TNG staff for their support, in particular Massimo Cecconi and Giovanni Mainella. [GCN OPS NOTE(23apr11): Per author's request, the last sentence was added.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11964 SUBJECT: GRB 110422A: correction to the GCN circ. 11958 DATE: 11/04/23 00:35:18 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI) report: In the GCN circ. 11958 due to misprint the author's name is spelled incorrectly. The names of the author's of the GCN circ. 11958 should be read as follows: E. Klunko (ISTP), A. Pozanenko (IKI) I apologize for possible inconvenience. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11965 SUBJECT: GRB 110422A: Enhanced Swift-XRT position DATE: 11/04/23 04:00:39 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1328 s of XRT Photon Counting mode data and 3 UVOT images for GRB 110422A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 112.04671, +75.10666 which is equivalent to: RA (J2000): 07h 28m 11.21s Dec (J2000): +75d 06' 24.0" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11966 SUBJECT: GRB 110422A: THO optical observations DATE: 11/04/23 04:09:32 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report: Taurus Hill Observatory's (A95) Celestron C-14 (OTA) telescope 14" FL 3910 mm with NextGEN 0.5X optical reducer and SBIG ST-8XME camera were used to detect GRB 110422A optical afterglow. The observations were started at 2011-04-22 20:26:30 (UT) and stopped at 2011-04-22 20:57:20 (UT) (~5 hours after the trigger). Six unfiltered observations with 300s exposure time were made. The afterglow was detected at following position RA 7 28 10.98 and DEC +75 06 25.4 consistent those given by Elunko E. et al. (GCN 11958) to within positional errors. The following magnitudes were obtained from the observations using NOMAD1 1651-0051346 (R = 16.040) as the comparison: Tmid(s)+T0 Filter Exp (sec) Mag Mag err Limit (sigma 3) 17285 unfilt 300 19.5 0.7 19.7 17535 unfilt 300 19.6 0.8 19.7 18152 unfilt 300 19.4 0.7 19.7 18462 unfilt 300 19.7 0.9 19.7 A png image of the 3x300sec clear filter observations is available at the following URL link: http://cutenews.kassiopeia.net/data/upimages/GRB_110422A_OA_THO.png //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11967 SUBJECT: GRB 110422A: CQUEAN griz Observation DATE: 11/04/23 06:42:52 GMT FROM: Yiseul Jeon at SNU/CEOU Yiseul Jeon, Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ), Soojong Pak, Hyeongju Jeong, (Kyunghee University) We observed GRB 110422A (Mangano et al. GCN 11957) with griz filters using CQUEAN camera on the 2.1m telescope at the McDonald observatory, TX. The observation started at 2011 April 23, 02:53:11 UT, about 11.19 hours after the BAT trigger. We confirm a bright afterglow in all the griz images at the location reported earlier (Xu et al. GCN 11961; Evans et al. GCN 11965), with a preliminary photometry of r ~ 20.36 +- 0.05 AB mag, based on the photometric standard star data taken on the same night. Further analysis of the data is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11968 SUBJECT: GRB 110422A: Swift-XRT refined Analysis DATE: 11/04/23 11:27:20 GMT FROM: Vanessa Mangano at INAF-IASFPA V. Mangano (INAF-IASFPA) and B. Sbarufatti (INAF OAB/INAF IASFPA) report on behalf of the Swift-XRT team: We have analysed 3.5 ks of XRT data for GRB 110422A (Mangano et al. GCN Circ. 11957), from 804 s to 12.7 ks after the BAT trigger. The data comprise 394 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 11965). The light curve can be modelled with an initial power-law decay with an index of alpha=1.02 (+/-0.03), followed by a break at T+7585 s to an alpha of 2.2 (+0.5, -0.4). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.99 (+/-0.09). The best-fitting absorption column is 1.94 (+0.26, -0.24) x 10^21 cm^-2, in excess of the Galactic value of 4.2 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.13 (+0.11, -0.10) and a best-fitting absorption column of 2.28 (+0.31, -0.29) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (6.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.28 (+0.31, -0.29) x 10^21 cm^-2 Galactic foreground: 4.2 x 10^20 cm^-2 Excess significance: 12.8 sigma Photon index: 2.13 (+0.11, -0.10) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00451901. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11969 SUBJECT: GRB 110422A: Swift/UVOT Detection of optical afterglow DATE: 11/04/23 13:02:09 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (MSSL-UCL) and V. Mangano (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 110422A 822 s after the BAT trigger (Mangano et al., GCN Circ. 11957). An optical afterglow consistent with the optical position found by Klunko et al. (GCN 11958) and others is found in the UVOT, and is clearly fading. It is detected in initial exposures in both white and b, and also in v and u when the initial exposures are summed up. Preliminary magnitudes and 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 822 972 147 18.80 ± 0.12 white (summed) 1054 1766 97.2 19.5 ± 0.23 white 7837 8037 197 >20.4 v (summed) 1104 2336 156 18.72 ± 0.35 b 1029 1049 19.4 18.02 ± 0.3 b (summed) 1202 2435 156 18.97 ± 0.22 u (summed) 1004 2410 175 18.8 ± 0.26 w1 (summed) 980 2385 175 >19.4 m2 (summed) 1128 2360 156 >19.4 w2 (summed) 1079 2310 156 >19.6 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). [GCN OPS NOTE(23apr11): Per author's request, the spelling on the Klunko reference was corrected.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11970 SUBJECT: GRB 110422A: Further NOT observation DATE: 11/04/23 22:23:51 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS), J. P. U. Fynbo (DARK/NBI), M. Nielsen (NOT), and P. Jakobsson (U. Iceland) report on behalf of a large collaboration: We continued to observe the field of GRB 110422A (Mangano et al., GCN 11957) at the Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 2x300 s, 3x300 s, and 3x300 s images in the R, V, and I filters, respectively. The images, with an airmass ~1.5, were still taken with strong wind. The optical afterglow (Elunko et al., GCN 11958; Xu et al., GCN 11961) has decayed to R=21.41+/-0.10 mag with a median time 21:06:08.9 UT on April 23 (i.e., 29.4 hr after the BAT trigger), compared with our previous measurement R=20.00+/-0.02 mag, both calibrated with the #1651-0050630 star (R1=19.08) in the USNO B1 catalog. The observations at the two epochs indicates a power-law decay index of ~0.8 for the R-band lightcurve. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11971 SUBJECT: Konus-Wind observation of GRB 110422A DATE: 11/04/24 09:30:07 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long bright GRB 110422A (Swift-BAT trigger #451901: Mangano et al., GCN 11957; Palmer et al., GCN 11959) triggered Konus-Wind at T0(KW)=56502.948 s UT (15:41:42.948). The burst light curve shows a multipeaked structure with a duration of ~40 s. As observed by Konus-Wind the burst had a fluence of (8.56 +/- 0.02)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+18.128 s of (1.20 +/- 0.15)x10^-5 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+38.656 s) can be fitted (in the 20 keV - 2 MeV range) by the GRB (Band) model for which: the low-energy photon index is alpha = -0.65 +/- 0.06, the high energy photon index beta = -2.96(-0.19, +0.14), the peak energy Ep = 152 +/- 5 keV (chi2 = 96.8/64 dof). The spectrum at the maximum count rate (measured from T0+17.664 to T0+18.432 s) is well fitted (in the 20 keV - 2 MeV range) by the GRB (Band) model, for which: the low-energy photon index alpha = -0.53 (-0.14, +0.17), the high energy photon index beta = -2.65 (-0.62, +0.28), the peak energy Ep = 246(-34, +37) keV (chi2 = 55.7/48 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB110422_T56502/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11972 SUBJECT: GRB110422A: MITSuME Ishigakijima Optical Observation DATE: 11/04/24 13:08:22 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 110422A (Mangano et al., GCNC 11957) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2011-04-23 12:44:54 UT, (~21 hours after the burst). We detected the previously reported afterglow (Klunko et al., GCNC 11958; Gres et al., GCNC 11960) in Rc band. Photometric results and three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic ---------------------------------------------------------------------- 0.89834 13:15:32 2400.0 >21.0 20.9 0.3 >19.3 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] [GCN OPS NOTE(24apr11): Per author's request, the "110322" was changed to "110422A" in the first sentence.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11973 SUBJECT: GRB 110422A: optical observations in CrAO DATE: 11/04/24 22:48:24 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 110422A (Mangano et al., GCN 11957) with AZT-11 telescope of CrAO between Apr. 22 (UT) 19:13 and 20:11. We clearly detect the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 11960, Xu et al. GCN 11961). The photometry is based on the USNO B1.0 star 1651-0050626 (07 28 13.15 +75 06 51.5) assuming R=18.56 : T0+ Filter, Exposure, mag. (mid, d) (s) 0.1675 R 20x180 19.32 +/-0.08 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11974 SUBJECT: GRB110422A: NOT optical follow-ups DATE: 11/04/25 21:46:49 GMT FROM: Dong Xu at Weizmann Inst Dong Xu (WIS), Erkki Kankare, Tuomas Kangas (U. Turku), and Pall Jakobsson (U. Iceland) report on behalf of a large collaboration: We continued to observe the field of GRB 110422A (Mangano et al., GCN 11957) at the Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 2x360 s in the R filter with some clouds and a seeing ~0.9". The optical afterglow (Elunko et al., GCN 11958; Gres et al., GCN 11960; Xu et al., GCN 11961) has decayed to R=22.5+/-0.2 mag with a median time 21:17:58.8 UT on April 25 (i.e., 77.6 hr after the BAT trigger), calibrated with the #1651-0050630 star (R1=19.08) in the USNO B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11975 SUBJECT: GRB 110422A: Herschel observation scheduled DATE: 11/04/25 21:51:12 GMT FROM: Dong Xu at Weizmann Inst Dong Xu (WIS), Maohai Huang (CAS), Bing Zhang (UNLV) report on behalf of a large collaboration: European Space Agency's Herschel Space Observatory is scheduled to make far infrared photometric observations of GRB 110422A on 30 April around 14UT in 70ìm and 170ìm bands, and two follow-ups on 2-3 May (time to be decided) in 70,170,250,350,500ìm bands, and on 6-7 May in 250,350,500ìm bands. This would be the first time a cosmological GRB is observed in 70-350ìm. Other facilities are encouraged to obtain results of GRB 110422A across the spectrum on those Herschel observing days. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11976 SUBJECT: GRB 110422A: Suzaku WAM observation of the prompt emission DATE: 11/04/26 11:08:37 GMT FROM: Masanori Ohno at ISAS/JAXA W. Iwakiri, Y. Terada, M. Tashiro, K. Takahara, T. Yasuda (Saitama U.), T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.), N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), S. Sugita (Nagoya U.), Y. E. Nakagawa (Waseda U.), N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The bright GRB 110422A (Swift/BAT trigger #451901 ; Mangano et al., GCN 11957; Palmer et al., GCN 11959) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 15:41:45 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-2s, ending at T0+35s with a duration (T90) of about 22 seconds. The fluence in 100 - 1000 keV was 3.60 (+/- 0.14) x10-5 erg/cm2. The 1-s peak flux measured from T0+18s was 14.5 (+/- 0.9) photons/cm2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-2s to T0+35s is well fitted by a single power-law with a photon index of 2.83 (+/- 0.11) (chi2/d.o.f = 21.3/14). All the quoted errors are at statistical 90% confidence level. The light curves for this burst will be appeared at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11977 SUBJECT: GRB 110422A: tentative redshift from TNG DATE: 11/04/26 15:51:06 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), D. Fugazza (INAF/Brera), P. D'Avanzo (INAF/Brera), V. D'Elia (ASI/ASDC), A. Melandri (INAF/Brera), S. Piranomonte (INAF/Roma), J.P.U. Fynbo (DARK/NBI), M. Cecconi (INAF/TNG), G. Mainella (INAF/TNG), report on behalf of a larger collaboration: We observed the afterglow of GRB 110422A (Mangano et al., GCN 11957; Klunko et al., GCN 11958) with the Italian TNG located in La Palma. A single 700 s spectroscopic exposure could be taken due to rising humidity (see also Melandri et al., GCN 11963). Observations started on 2011 April 22.998 UT (8.25 hr after the GRB). The adopted grism was LR-B, covering the wavelength range 3600-8200 AA. We detect a clear absorption feature at 4290 AA. Interpreting this as the (unresolved) CIV doublet yields a redshift of z = 1.77. At the same redshift we find a few other lines which we interpret as due to Si IV and Fe II. We thus propose z = 1.77 to be the redshift of GRB 110422A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11978 SUBJECT: GRB 110422A: Redshift confirmation from GTC DATE: 11/04/26 17:34:58 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (DARK/NBI), A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC) report on behalf of a larger collaboration: We have observed the afterglow of GRB 110422A (Mangano et al., GCNC 11957; Klunko et al., GCNC 11958) using the 10.4m GTC telescope located in La Palma (Spain). Spectroscopic observations were performed with mean epoch of April 25th at 22:55 UT (3.3 days after the burst) and consisted of a single 1800s exposure using the R500B grating (resolution ~500). The spectrum shows several absorption features that we identify as due to C IV, Al II, Al III, Fe II, Mg II, and Mg I at a redshift of 1.770+/-0.001, consistent with the results of Malesani et al. (GCNC 11977). We hence confirm this to be the redshift of the GRB. We acknowledge excellent support from the GTC staff, in particular Rene Ruten. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11979 SUBJECT: GRB 110422A: optical observations in CrAO, second epoch DATE: 11/04/26 20:25:41 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 110422A (Mangano et al., GCN 11957) with AZT-11 telescope of CrAO between Apr. 24 (UT) 19:21 - 21:10. We detect the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 11960, Xu et al. GCN 11961). The photometry is based on the USNO B1.0 star 1651-0050626 (07 28 13.15 +75 06 51.5) assuming R=18.56: T0+ Filter, Exposure, mag. (mid, d) (s) 2.1910 R 36x180 21.3 +/-0.3 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11985 SUBJECT: GRB 110422A: Update of Herschel FIR observation schedule DATE: 11/04/29 17:15:41 GMT FROM: Maohai Huang at NAOC Maohai Huang (NAOC), Bing Zhang (UNLV), Dong Xu (WIS), Jinsong Deng (NAOC), Liping Xin (NAOC), Yulei Qiu (NAOC) report on behalf of Herschel OT1_mhuang01 Open Time program: This is an update of ESA's schedule to search and observe far infrared after glowof GRB 110422A using photometers of PACS (70,110micron) and SPIRE (250, 350, 500micron) instruments on-board Herschel Space Observatory, with sensitivities of several mJy/beam. Date ----- Time ---- Instrument 2011-04-30T13:59:28UT PacsPhoto 2011-04-30T14:15:29UT PacsPhoto 2011-05-03T19:28:25UT SpirePhoto 2011-05-04T01:24:55UT PacsPhoto 2011-05-04T01:40:56UT PacsPhoto 2011-05-08T02:43:38UT SpirePhoto 2011-05-09T21:41:44UT PacsPhoto 2011-05-09T21:57:45UT PacsPhoto 2011-05-13T18:47:21UT SpirePhoto For more details and updates (if any) see http://herschel.esac.esa.int/observing/ScheduleReport.html We strongly encourage ground and space instruments to collect data across full spectral range, especially in X-ray, optical, near/mid IR, millimeter/submillimeter, and radio bands, of GRB 110422A on observing days of Herschel. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11986 SUBJECT: GRB 110422A: optical observations in CrAO DATE: 11/05/01 10:22:01 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI), E. Klunko (ISTP) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 110422A (Mangano et al., GCN 11957) with ZTSh telescope of CrAO on Apr. 28 between (UT) 20:43: and 21:52. We clearly detect the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 11960, Xu et al. GCN 11961). The photometry is based on the USNO B1.0 star 1651-0050626 (07 28 13.15 +75 06 51.5) assuming R=18.56 : T0+ Filter, Exposure, mag. (mid, d) (s) 6.2328 R 55x60 22.28 +/-0.14 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12006 SUBJECT: GRB 110422A: Herschel FIR observation preliminary report DATE: 11/05/05 03:12:33 GMT FROM: Maohai Huang at NAOC Maohai Huang (NAOC), Bing Zhang (UNLV), Dong Xu (WIS), Jinsong Deng (NAOC), Liping Xin (NAOC), Yulei Qiu (NAOC) report on behalf of Herschel OT1_mhuang01 Open Time program: Herschel Space Observatory has observed GRB 110422A according to the plan (Huang et al GCN 11985). Preliminary data reduction has shown statistically significant (S/N ~ 10) detection in 170um and 250um bands at a few mJy level. Scheduled follow-up observations and further analyses of foreground/background sources will be conducted to determine whether the emission is variable (dominated by the afterglow) or from the host galaxy of GRB 110422A and Galactic ISM. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12007 SUBJECT: GRB 110422A: MASTER first 30 min OT light curve DATE: 11/05/05 06:42:02 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs O. Gres, K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Chuvalaev Irkutsk State University V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka (Baykal lake) was pointed to the GRB 110422A (Mangano et al., GCN Circ 11957) 53 sec after GRB time at 2011-04-22 15:42:48.507 UT (Gres et al., GCN Circ 11960). We see OT (Klunko et al. GCN 11958) on all images in both polarizations in R-band. The results of the our photometry are: mag err exp t-t_trig mag err exp t-t_trig R/ s mean (hours) R\ s mean (hours) 14.89 0.29 10 0.0166 15.28 0.43 10 0.0163 15.03 0.17 20 0.0272 15.3 0.25 20 0.0272 16.04 0.47 30 0.0400 15.73 0.31 30 0.0397 15.73 0.38 40 0.0551 15.77 0.38 40 0.0548 16.35 0.41 50 0.0729 16.05 0.27 50 0.0724 16.53 0.37 60 0.0938 16.53 0.32 60 0.0934 16.36 0.45 80 0.1190 16.35 0.41 80 0.1186 16.68 0.34 100 0.1502 16.78 0.33 100 0.1498 17.74 0.79 120 0.1871 17.17 0.34 120 0.1868 17.78 0.59 150 0.2319 17.52 0.33 150 0.2315 17.26 0.3 180 0.2834 17.56 0.32 180 0.2831 17.22 0.33 180 0.3403 17.78 0.48 180 0.3399 17.2 0.32 180 0.3957 18.32 0.87 180 0.3952 17.59 0.45 180 0.4513 18.71 1.27 180 0.4510 18.08 0.91 180 0.5066 19.25 2.64 180 0.5063 The LC's are available at: http://observ.pereplet.ru/images/GRB110422/grb110422.png The message may be cited.