GRB141121A

This page lists all entries on GRB141121A in GRBweb

Summary IPN Swift GCN 17075 GCN 17076 GCN 17077 GCN 17078 GCN 17080 GCN 17081 GCN 17082 GCN 17083 GCN 17084 GCN 17085 GCN 17086 GCN 17087 GCN 17088 GCN 17089 GCN 17090 GCN 17091 GCN 17092 GCN 17093 GCN 17096 GCN 17098 GCN 17099 GCN 17100 GCN 17101 GCN 17102 GCN 17103 GCN 17104 GCN 17105 GCN 17106 GCN 17109 GCN 17110 GCN 17111 GCN 17112 GCN 17113 GCN 17114 GCN 17116 GCN 17117 GCN 17118 GCN 17119 GCN 17124 GCN 17128 GCN 17138 GCN 17145 GCN 17156 GCN 17191 GCN 17284 GCN 17656 GCN 17108

Summary table
Variable Value Source
T0 3:36:13 UTC GCN_circulars,Konus-Wind Det
ra 122.6693° Swift
decl 22.2173° Swift
pos_error 6.47e-05° Swift
T90 549.9 s Swift
T90_start 3:50:43 UTC Swift
fluence 5.30e-06 erg/cm² Swift
redshift 1.4700 GCN_circulars,Other
T100 1419.9 s
GBM_located False
mjd 56982.15015046296 GCN_circulars,Konus-Wind Det
IPN table
GRB_name GRB141121A
ra 122.6667°
decl 22.2333°
pos_error 5.00e-02°
redshift 1.4700
Swift table
GRB_name GRB141121A
t_trigger 3:50:43 UTC
ra 122.6693°
decl 22.2173°
pos_error 6.47e-05°
T90 549.9 s
fluence 5.30e-06 erg/cm²
redshift 1.4700
GCN 17075 table
GRB_name GRB141121A
GCN_number 17075
Detection_method Swift Det
t_trigger 3:50:43 UTC
ra 122.6680°
decl 22.2250°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17075 SUBJECT: GRB 141121A: Swift detection of a burst DATE: 14/11/21 04:07:51 GMT FROM: David Palmer at LANL A. Y. Lien (GSFC/UMBC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 03:50:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141121A (trigger=619182). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 122.668, +22.225 which is RA(J2000) = 08h 10m 40s Dec(J2000) = +22d 13' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows no significant structure, as usual for an image trigger. The XRT began observing the field at 03:56:45.6 UT, 362.4 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 122.6700, 22.2177 which is equivalent to: RA(J2000) = +08h 10m 40.80s Dec(J2000) = +22d 13' 03.7" with an uncertainty of 4.8 arcseconds (radius, 90% containment). This location is 27 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. The initial flux in the 2.5 s image was 6.07e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 370 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 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 0.05. Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 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.)
GCN 17076 table
GRB_name GRB141121A
GCN_number 17076
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17076 SUBJECT: GRB141121A: BOOTES-2/TELMA upper limit DATE: 14/11/21 06:26:08 GMT FROM: Juan Carlos Tello at IAA-CSIC J. C. Tello (IAA-CSIC), J. Gorosabel (IAA-CSIC, UPV-EHU) and A, J. Castro-Tirado (IAA-CSIC, ISA-UMA), on behalf of a larger collaboration, report: Following the detection of GRB 141121A by Swift (Lien et al., GCNC 17075), the 0.6m TELMA robotic telescope at the BOOTES-2 astronomical station Malaga (Spain), responded to the GRB location in poor weather conditions (through clouds) starting at 04:01:57 UT (i.e. 11 min postburst). The co-add of 10 images (i-band) starting at 04:06:03 UT and ending in 04:17:17 UT (i.e. 16-27min post burst) (60s integrations) provides an upper limit of i > 16.5 for any object within the Swift/XRT error box. Further observations are planned.
GCN 17077 table
GRB_name GRB141121A
GCN_number 17077
Detection_method MAXI Det
t_trigger 3:44:47 UTC
ra 122.9280°
decl 22.0530°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17077 SUBJECT: GRB 141121A: MAXI/GSC detection DATE: 14/11/21 06:31:44 GMT FROM: H. Negoro at Nihon U. F. Honda, K. Fukushima, H. Negoro (Nihon U.), N. Kawai (Tokyo Tech), S. Nakahira (JAXA), M. Serino (RIKEN), S. Ueno, H. Tomida, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Morii, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), Y. Tachibana, T. Yoshii (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, D. Uchida (Osaka U.), M. Nakajima, T. Onodera, K. Suzuki, T. Namba, M. Fujita (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, A. Kawagoe (Chuo U.), M. Yamauchi, Y. Morooka, D. Itoh (Miyazaki U.), K. Yamaoka (Nagoya U.) We report the MAXI/GSC detection of GRB 141121A (Li et al. GCN 17075). The MAXI/GSC detected the source in the scan transit at 2014-11-21T03:44:47 (UT), earlier than about 6 min before the BAT trigger. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (122.928 deg, 22.053 deg) = (08 11 42, +22 03 10) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.44 deg and 0.4 deg respectively. The roll angle of long axis from the north direction is 174.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). This position is consistent with that reported as GRB 141121A. The X-ray flux averaged over the scan was 57 +- 17 mCrab (4-10keV, 1 sigma error). There was no significant excess flux in the previous transit at UT 00:39. and in the next transit at 05:17 UT with an upper limit of 20 mCrab for each. A simple power-law fit to the GSC spectrum gives a power-law index of 2.3 +/- 1.0. These nature implies that the source is a long-GRB, or a new X-ray transient. The followup observations are strongly encouraged to reveal the nature of the source.
GCN 17078 table
GRB_name GRB141121A
GCN_number 17078
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 17078 SUBJECT: GRB 141121A: GROND Afterglow candidate DATE: 14/11/21 07:15:06 GMT FROM: Alexander Kann at TLS Tautenburg M. Tanga (MPE Garching), D. A. Kann (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 141121A (Swift trigger 619182; A. Y. Lien et al., GCN 17075) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 05:52 UT on November 21, 2014, 2.02 hours after the GRB trigger. They were performed at an average seeing of 1".4 and at an average airmass of 2.3. Within the XRT error circle reported by Lien et al., we detect a bright source in all bands. This source is not detected in the SDSS, therefore we consider it to be the afterglow of GRB 141121A. The source lies at: RA (J2000) = 08:10:40.62 Dec. (J2000) = +22:13:01.8 with an error of 0".3 in each coordinate. Based on total exposures of 7.7 minutes in g'r'i'z' and 8.0 minutes in JHK, at a midtime of 2.34 hrs after the burst, we measure the following preliminary magnitudes (AB magnitude system): g' = 20.0 +/- 0.1 mag, r' = 19.8 +/- 0.1 mag, i' = 19.6 +/- 0.1 mag, z' = 19.4 +/- 0.1 mag, J = 19.4 +/- 0.2 mag, and H = 19.2 +/- 0.2 mag. The magnitudes are calibrated against SDSS and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.05 in the direction of the burst (Schlegel et al. 1998).
GCN 17080 table
GRB_name GRB141121A
GCN_number 17080
Detection_method Swift-XRT Det
ra 122.6695°
decl 22.2174°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17080 SUBJECT: GRB 141121A: Enhanced Swift-XRT position DATE: 14/11/21 10:50:36 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 1073 s of XRT Photon Counting mode data and 5 UVOT images for GRB 141121A, 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 = 122.66947, +22.21741 which is equivalent to: RA (J2000): 08h 10m 40.67s Dec (J2000): +22d 13' 02.7" with an uncertainty of 1.5 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.
GCN 17081 table
GRB_name GRB141121A
GCN_number 17081
Detection_method Other
redshift 1.4700
Circular_text TITLE: GCN CIRCULAR NUMBER: 17081 SUBJECT: GRB 141121A: Keck redshift DATE: 14/11/21 12:23:41 GMT FROM: Daniel Perley at Caltech D. A. Perley, C. P. Ott (Caltech), M. Modjaz, and D. Fierroz (NYU) report: We acquired a spectrum of the afterglow of GRB 141121 (Lien et al., GCN 17075; Tanga et al., GCN 17078) using the Low-Resolution Imaging Spectrometer (LRIS) on the Keck I 10-meter telescope. A single exposure of 900 seconds was acquired using the B600 and R400 gratings, covering a wavelength range from 3116 to 10264 Angstroms. In the reduced spectrum, we identify the Mg II (2796,2803) doublet, the Fe II (2599) doublet, Fe II (2585), and Fe II (2344) at a common redshift of z=1.47 (as well as many absorption lines at bluer wavelengths). No higher-redshift absorption systems are observed and no DLA is present down to the blue limit of our spectrum (suggesting an upper limit of z<1.56) so we associate this with the redshift of the GRB.
GCN 17082 table
GRB_name GRB141121A
GCN_number 17082
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17082 SUBJECT: GRB 141121A: LCO-FTN observations DATE: 14/11/21 12:46:18 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy S. Dichiara and C. Guidorzi (U. Ferrara) on behalf of a large collaboration report: The Las Cumbres Observatory 2-m Faulkes Telescope North in Hawaii began observing Swift GRB 141121A (Lien et al. GCN Circ 17075) on November 21 at 10:42:54 UT, i.e. ~6.9 hours after the BAT trigger, with the r' and i' filters. We clearly detect the optical afterglow (Tanga et al. GCN 17078; Perley et al. GCN 17081) with the following magnitudes: Mid time from Total Exp Filter Magnitude trigger (hr) (s) ------------------------------------------------- 7.0 120x5 r' 19.62 +- 0.06 7.2 120x5 i' 19.42 +- 0.06 ------------------------------------------------- Magnitudes are calibrated against nearby SDSS stars. Compared with GROND values we note a possible hint for rebrightening or, in any case, for a very shallow decay between the two epochs.
GCN 17083 table
GRB_name GRB141121A
GCN_number 17083
Detection_method Swift-BAT Det
ra 122.6650°
decl 22.2060°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17083 SUBJECT: GRB 141121A: Swift-BAT refined analysis DATE: 14/11/21 14:40:09 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 141121A (trigger #619182) (Lien, et al., GCN Circ. 17075). The BAT ground-calculated position is RA, Dec = 122.665, 22.206 deg which is RA(J2000) = 08h 10m 39.5s Dec(J2000) = +22d 12' 22.5" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 32%. The mask-weighted light curve shows a very broad multi-peaked structure with the first emission episode running from T-50 to T+450 sec, with at least four superimposed peaks. Then there is a return to baseline followed by another episode from T+550 to T+675 sec. The spacecraft slewed away from the burst position at around T+825 sec. T90 (15-350 keV) is 549.9 +- 37.4 sec (estimated error including systematics). The time-averaged spectrum from T+46.54 to T+663.07 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.73 +- 0.13. The fluence in the 15-150 keV band is 5.3 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+230.14 sec in the 15-150 keV band is 0.9 +- 0.3 ph/cm2/sec. 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/619182/BA/
GCN 17084 table
GRB_name GRB141121A
GCN_number 17084
Detection_method Swift-XRT Other
redshift 1.4700
Circular_text TITLE: GCN CIRCULAR NUMBER: 17084 SUBJECT: GRB 141121A: RATIR Optical Observations DATE: 14/11/21 17:02:31 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/11 21.33 to 2014/11 21.53 UTC (4.00 to 8.84 hours after the BAT trigger), obtaining a total of 3.78 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections: r 19.62 +/- 0.02 i 19.45 +/- 0.02 z 19.76 +/- 0.12 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Over the course of our observations, the flux in r and i fades slightly as t^-0.15, with t measured from the time of the BAT trigger. Our measurements in z are noisier, but consistent with this shallow decay. We confirm this as the afterglow reported by Tanga et al. (GCN 17078) and Dichiara et al. (GCN 17082), for which Perley et al. (GCN 17081) report a spectroscopic redshift of 1.47. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. The RATIR team congratulates the Swift team on 10 years of operation.
GCN 17085 table
GRB_name GRB141121A
GCN_number 17085
Detection_method Swift-UVOT Det
ra 122.6693°
decl 22.2173°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17085 SUBJECT: GRB 141121A: Swift/UVOT Detections DATE: 14/11/21 19:03:15 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 141121A 371 s after the BAT trigger (Lien et al., GCN Circ. 17075). A source consistent with the optical position (Tanga et al. GCN Circ. 17078) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:10:40.63 = 122.66928 (deg.) Dec (J2000) = 22:13:02.2 = 22.21728 (deg.) with an estimated uncertainty of 0.5 arcsec. (radius, 90% confidence). The source shows an unusual light curve with little evidence for variability. The source is detected in all UVOT filters although the detections in v and w2 are not highly significant. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 371 520 147 >20.1 white 6067 6266 197 20.2 +/- 0.2 v 527 547 19 >18.3 v 15373 16025 635 20.3 +/- 0.3 b 5862 6062 197 19.8 +/- 0.2 u 5562 5714 149 19.4 +/- 0.2 u 27756 28325 556 19.3 +/- 0.1 w1 3830 3897 66 19.4 +/- 0.3 w1 26850 27750 886 19.7 +/- 0.1 m2 21039 21939 886 20.4 +/- 0.2 w2 9514 12083 771 21.2 +/- 0.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).
GCN 17086 table
GRB_name GRB141121A
GCN_number 17086
Detection_method Swift-XRT Other
redshift 1.4700
Circular_text TITLE: GCN CIRCULAR NUMBER: 17086 SUBJECT: GRB 141121A: Swift-XRT refined Analysis DATE: 14/11/22 00:08:04 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), J.A. Kennea (PSU), V. Mangano (PSU) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 7.3 ks of XRT data for GRB 141121A (Lien et al. GCN Circ. 17075), from 355 s to 58.1 ks after the BAT trigger. The data comprise 305 s in Windowed Timing (WT) mode (the first 5 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. 17080). The late-time light curve (from T0+3.8 ks) can be modelled with a series of power-law decays. The initial decay index is alpha=1.50 (+/-0.13). At T+15.8 ks the decay steepens to an alpha of 4.3 (+1.2, -0.7) before breaking again at T+25.6 ks to a final decay with index alpha=0.1 (+0.6, -1.5). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.52 (+/-0.04). The best-fitting absorption column is 6.2 (+/-1.0) x 10^21 cm^-2, at a redshift of 1.47, in addition to the Galactic value of 4.3 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.93 (+/-0.12) and a best-fitting absorption column of 3.9 (+2.2, -2.0) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 4.3 x 10^20 cm^-2 Intrinsic column: 3.9 (+2.2, -2.0) x 10^21 cm^-2 at z=1.47 Photon index: 1.93 (+/-0.12) If the light curve continues to decay with a power-law decay index of 0.1, the count rate at T+24 hours will be 0.032 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x 10^-12 (1.3 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00619182. This circular is an official product of the Swift-XRT team.
GCN 17087 table
GRB_name GRB141121A
GCN_number 17087
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17087 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/11/23 07:05:41 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 22.28 to 2014/11 22.53 UTC (26.79 to 32.94 hours after the BAT trigger), obtaining a total of 4.93 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r 20.84 +/- 0.03 i 20.68 +/- 0.03 z > 20.02 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The source has faded in r and i by 1.2 magnitudes or roughly t^-0.73 since our observations on the first night (Watson et al., GCN 17084), confirming that it is the afterglow. This fading is steeper than the t^-0.15 fading seeing during our observations on the first night. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17088 table
GRB_name GRB141121A
GCN_number 17088
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 17088 SUBJECT: GRB 141121A: MITSuME Akeno Optical observation DATE: 14/11/23 11:44:55 GMT FROM: Taketoshi Yoshii at Tokyo Tech S. Kurita, Y. Saito, Y. Tachibana, T. Yoshii, H. Ohuchi, Y. Yano, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 141121A (Lien et al., GCN Circular #17075) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2014-11-21 12:59:47 UT (~9 h after the burst). We detected the previously reported optical afterglow (Tanga et al., GCN Circular #17078) in the g',Rc and Ic band. The measured magnitudes are listed below. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ---------------------------------------------------------------------- 32947 17:07:07 12840 20.8 +/- 0.2 19.7 +/- 0.1 19.4 +/- 0.2 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.
GCN 17089 table
GRB_name GRB141121A
GCN_number 17089
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17089 SUBJECT: GRB 141121A: AAO optical observations DATE: 14/11/23 13:36:48 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), A. Volnova (IKI), Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with AS-32 (0.7m) telescope of Abastumani Observatory. Observations were performed under mean seeing (FWHM) of 3.5". We obtained several unfiltered images on Nov. 21 starting on (UT) 20:01:35. Within enhanced XRT position (Evans et al., GCN 17080) we clearly detected afterglow of GRB 141109A (Tanga et al., GCN 17078; Perley et al., GCN 17081). Preliminary photometry is following: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-21 20:01:35 0.73241 clear 54*120 20.08 0.05 The photometry is based on several SDSS-DR9 stars R magnitudes transformed from SDSS-DR9 based on Lupton transformations: SDSS_id R(Lupton) J081028,70+221318,9 16,317 J081049,68+221012,2 17,148 J081048,76+220822,7 14,413 J081106,66+221346,9 14,626
GCN 17090 table
GRB_name GRB141121A
GCN_number 17090
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17090 SUBJECT: GRB 141121A: Continued RATIR Optical Observations - Rebrightening DATE: 14/11/23 16:20:16 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 23.31 to 2014/11 23.54 UTC (51.53 to 57.18 hours after the BAT trigger), obtaining a total of 3.80 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections: r = 20.60 +/- 0.03 i = 20.44 +/- 0.03 z = 20.06 +/- 0.29 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow appears to have rebrightened by about 0.24 magnitudes in r and i compared to our observations at 30 hours (Butler et al., GCN 17087). We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17091 table
GRB_name GRB141121A
GCN_number 17091
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 17091 SUBJECT: GRB 141121A: MITSuME Ishigakijima Optical Observation DATE: 14/11/24 01:39:20 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 and OISTER collaboration: We observed the field of GRB 141121A (Lien et al., GCNC 17075) 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 2014-11-23 17:42:18 UT (~2.6 days after the burst). We detected the previously reported afterglow (Tanga et al., GCNC 17078; Perley et al., GCNC 17081) in all the three bands. Photometric results of the OT are listed below. We used SDSS-DR7 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err -------------------------------------------------------------------------- 2.61049 18:29:49 4800.0 21.02 0.08 20.44 0.07 19.64 0.09 -------------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 17092 table
GRB_name GRB141121A
GCN_number 17092
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17092 SUBJECT: GRB 141121A: LCO-FTN rebrightening confirmation DATE: 14/11/24 09:58:43 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy S. Dichiara and C. Guidorzi (U. Ferrara) on behalf of a large collaboration report: The Las Cumbres Observatory 2-m Faulkes Telescope North in Hawaii re-observed Swift GRB 141121A (Lien et al. GCN Circ 17075) on November 23 at 10:43:39 UT, i.e. ~2.29 days after the BAT trigger, with the r' and i' filters. We confirm the rebrightening of the optical afterglow reported by RATIR (Watson et al. GCN 17090) with the following magnitudes: Mid time from Total Exp Filter Magnitude trigger (days) (s) ------------------------------------------------- 2.31 120x10 r' 20.61 +- 0.04 2.29 120x10 i' 20.34 +- 0.05 ------------------------------------------------- Magnitudes are calibrated against nearby SDSS stars. Observations are going on.
GCN 17093 table
GRB_name GRB141121A
GCN_number 17093
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17093 SUBJECT: GRB 141121A: Mondy optical observations DATE: 14/11/24 16:56:28 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), E. Klunko (ISTP), A. Volnova (IKI), M. Eselevich (ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy) on Nov., 23 starting on (UT) 20:57:39. We obtained several images in R-filter. In a combined image we clearly detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry is based on nearby SDSS stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-23 20:57:39 2.74025 R 39*120 20.53 0.04 We confirm re-brightening of the afterglow reported early (Watson et al. GCN 17090; Kuroda et al. GCN 17091; Dichiara et al. GCN 17092).
GCN 17096 table
GRB_name GRB141121A
GCN_number 17096
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17096 SUBJECT: GRB 141121A: RATIR Optical Observations - Fading Again DATE: 14/11/24 18:04:30 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 24.27 to 2014/11 24.53 UTC (74.70 to 80.86 hours after the BAT trigger), obtaining a total of 4.93 hours exposure in the r, i, and z band. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 20.68 +/- 0.03 i = 20.51 +/- 0.04 z > 20.48 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow has faded by about 0.08 magnitudes in r and i compared to our observations at 54 hours (Watson et al., GCN 17090). This corresponds to a shallow decay close to t^-0.2. Thus, the rebrightening reported by Watson et al. (GCN 17090) and confirmed by Dichiara et al. (GCN 17092) appears to have ended. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17098 table
GRB_name GRB141121A
GCN_number 17098
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 17098 SUBJECT: GRB 141121A: MITSuME Ishigakijima Optical Observation after 3 days DATE: 14/11/25 01:46:25 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 and OISTER collaboration: We observed the field of GRB 141121A (Lien et al., GCNC 17075) 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 2014-11-24 17:17:04 UT (~3.6 days after the burst). We detected the previously reported afterglow (Tanga et al., GCNC 17078; Perley et al., GCNC 17081; Kuroda et al., GCNC 17091) in all the three bands. Photometric results of the OT are listed below. We used SDSS-DR7 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err -------------------------------------------------------------------------- 3.60810 18:26:22 5100.0 21.39 0.13 20.37 0.08 19.90 0.12 -------------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 17099 table
GRB_name GRB141121A
GCN_number 17099
Detection_method AMI
Circular_text TITLE: GCN CIRCULAR NUMBER: 17099 SUBJECT: GRB 141121A: AMI 15 GHz detection DATE: 14/11/25 17:31:36 GMT FROM: Gemma Anderson at U of Oxford G. E. Anderson, R. P. Fender, T. D. Staley (University of Oxford), A. J. van der Horst (University of Amsterdam), A. Rowlinson (CASS) We observed the position of GRB 141121A (Lien et al., GCN 17075) at 15 GHz with the Arcminute Microkelvin Imager (AMI-LA) starting on 2014 Nov 24.17 to 24.33 UT, corresponding to 3 days post-burst. We have detected a radio source coincident with the optical counterpart (Tanga et al., GCN 17078) with a preliminary flux of 0.46 +/- 0.05 mJy. Earlier observations were conducted on 2014 Nov 21.16 to 21.25 UT and Nov 22.05 to 22.21 UT, corresponding to <6 minutes and 0.9 days post-burst, yielding a 3 sigma flux upper limit of 0.26 mJy and a marginal detection of 0.18 +/- 0.06 mJy, respectively. Further AMI monitoring is planned. We thank the AMI staff for scheduling these observations.
GCN 17100 table
GRB_name GRB141121A
GCN_number 17100
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17100 SUBJECT: GRB 141121A: RATIR Optical Observations - Steeper Fading DATE: 14/11/25 18:21:54 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 25.27 to 2014/11 25.54 UTC (98.75 to 105.00 hours after the BAT trigger), obtaining a total of 4.58 hours exposure in the r, i, and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 20.96 +/- 0.04 i = 20.75 +/- 0.04 z > 19.93 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow has faded by about 0.25 magnitudes in r and i compared to our observations at 78 hours (Butler et al., GCN 17096). This corresponds to a steepening of the temporal power law from t^-0.2 between 54 and 78 hours (Butler et al., GCN 17096) to t^-0.9 between 78 and 102 hours. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17101 table
GRB_name GRB141121A
GCN_number 17101
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17101 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/11/26 16:47:33 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 26.31 to 2014/11 26.53 UTC (123.55 to 128.80 hours after the BAT trigger), obtaining a total of 4.04 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 21.27 +/- 0.04 i = 21.04 +/- 0.04 z > 21.04 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow has faded by about 0.3 magnitudes in r and i compared to our observations at 102 hours (Watson et al., GCN 17100). This corresponds to a further steepening of the temporal power law from t^-0.9 between 78 and 102 hours (Watson et al., GCN 17100) to t^-1.3 between 102 and 126 hours. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17102 table
GRB_name GRB141121A
GCN_number 17102
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17102 SUBJECT: GRB 141121A: Continued Mondy optical observations DATE: 14/11/26 22:52:46 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy) on Nov., 26 starting on (UT) 20:16:58. We obtained several images in R-filter. In a combined image we clearly detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry is based on nearby SDSS stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-26 20:16:58 5.7120 R 39*120 21.38 0.09 The magnitude of the afterglow decreased about 0.9 mag since our previous observation (Mazaeva et al., GCN 17093) at 2.74 days after the burst trigger and thus we confirm gradual steepening of the afterglow light curve (Butler et al., GCN 17101).
GCN 17103 table
GRB_name GRB141121A
GCN_number 17103
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17103 SUBJECT: GRB 141121A: TSHAO optical observations DATE: 14/11/27 00:21:38 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Kusakin (Fesenkov Astrophysical Institute), E. Mazaeva (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory starting on Nov. 22 (UT) 21:45:26. We obtained several images in R-filter. In a combined image we clearly detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry is based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-22 21:45:26 1.8093 R 26*300 20.88 0.03
GCN 17104 table
GRB_name GRB141121A
GCN_number 17104
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17104 SUBJECT: GRB 141121A: WSRT radio detection DATE: 14/11/27 13:34:17 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst (University of Amsterdam) reports on behalf of a large collaboration: "We observed the position of the GRB 141121A afterglow at 4.9 GHz with the Westerbork Synthesis Radio Telescope at November 26 22.54 UT to November 27 09.34 UT, i.e. 5.78 - 6.23 days after the burst (GCN 17075). We detect a radio source with a flux density of 0.17 +/- 0.04 mJy at the position of the optical counterpart (GCN 17078). We would like to thank the WSRT staff for scheduling and obtaining these observations."
GCN 17105 table
GRB_name GRB141121A
GCN_number 17105
Detection_method Swift-XRT Other
redshift 1.4700
Circular_text TITLE: GCN CIRCULAR NUMBER: 17105 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/11/27 16:16:55 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 27.31 to 2014/11 27.54 UTC (147.50 to 153.22 hours after the BAT trigger), obtaining a total of 4.62 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections: r = 21.59 +/- 0.04 i = 21.39 +/- 0.04 z = 20.89 +/- 0.26 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow has faded by about 0.33 magnitudes in r and i compared to our observations at 126 hours (Butler et al., GCN 17101). This corresponds to a further steepening of the temporal power law from t^-1.3 between 102 and 126 hours (Watson et al., GCN 17100) to t^-1.8 between 126 and 150 hours. We detect a source 2.3 arcsec to the east of the optical transient, with r = 23.22 +/- 0.13, i = 23.11 +/- 0.13, and z > 21.02. This source is visible in earlier images, but due to its proximity to the brighter optical transient our automatic pipeline failed to produce photometry for it from those earlier images. We expect better photometry for this source once the afterglow has faded further. For a flat universe with H0 = 70 km/s/Mpc and OmegaM = 0.29, and at a redshift of 1.47 (Perley et al., GCN 17081) the angular separation of the afterglow and this source corresponds to a projected separation of 20 kpc. This separation is consistent with the source being the host galaxy of the GRB. If this source is the host galaxy, our photometry suggests that it is among the brightest ever observed at this redshift for optically bright GRBs (Hjorth et al. 2012, ApJ, 756, 187; Perley et al. 2013, ApJ, 778, 128). We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17106 table
GRB_name GRB141121A
GCN_number 17106
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17106 SUBJECT: GRB 141121A: three epochs of SAO RAS optical observations DATE: 14/11/27 18:23:54 GMT FROM: Vladimir Sokolov at SAO RAS A.S. Moskvitin and V.N. Komarova report on behalf of a larger team: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the SAO RAS 1-m Zeiss-1000 telescope at three nights: 2014.11.24/25, 25/26, 26/27. The GRB OT (Tanga et al., GCN 17078) is clearly detected in our stacked frames each night. Our charts can be found at ftp://ftp.sao.ru/pub/grb/GRB141121A/GRB141121A_z1000_24_25_26.jpg We used nearby SDSS stars for calibration. The "ugriz" magnitudes were converted to "UBVRI" with the Lupon-2005 equations. Our OT brightness measurements are in good agreement with R-band values estimated within the close epochs and reported in the GCN circulars: Kuroda et al. (GCN 17098), Mazaeva et al. (GCN 17102). Our OT magnitudes are also similar to r-band measurements by Watson et al. (GCN 17100) and Butler et al. (GCN 17101). Our preliminary results are presented in the following table: ----------------------------------------------------- Date T-T0 UT_start-end Exp.,s R_mag ----------------------------------------------------- 24.942 3.782 20:14--00:59 900 20.31+/-0.09 25.956 4.796 22:16--23:38 3600 20.86+/-0.04 26.980 5.820 22:12--00:50 4800 21.36+/-0.09 -----------------------------------------------------
GCN 17109 table
GRB_name GRB141121A
GCN_number 17109
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17109 SUBJECT: GRB 141121A: RATIR Optical and NIR Observations DATE: 14/11/28 16:04:21 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 28.29 to 2014/11 28.54 UTC (171.20 to 177.06 hours after the BAT trigger), obtaining a total of 4.62 hours exposure in the r, i, and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 21.87 +/- 0.05 i = 21.62 +/- 0.05 z > 21.03 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Compared to our previous observations (Butler et al., GCN 17101; Watson et al., GCN 17105), the afterglow continues to fade roughly as t^-1.7. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17110 table
GRB_name GRB141121A
GCN_number 17110
Detection_method INTEGRAL
Circular_text TITLE: GCN CIRCULAR NUMBER: 17110 SUBJECT: GRB 141121A: SPI-ACS/INTEGRAL observations DATE: 14/11/28 18:10:04 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), P. Minaev (IKI), V. Vybornov (IKI), A. Volnova (IKI), E. Mazaeva (IKI) report: We inspected the SPI-ACS data of INTEGRAL observatory covering trigger time of the Swift GRB 141121A (Lien et al., GCN 17075) and MAXI/GSC (Honda et al., GCN 17077). At the BAT/Swift trigger time of the GRB 141121A (UT) T0=03:50:43 we do not found any significant emission above background in SPI-ACS data in different time scales (0.05 s, 5 s, and 50 s). We also do not find any activity at the second BAT episode (T0+550 s to T0+675 s). At the time of about T0-800 s we found in SPI-ACS data the activity corresponding to the first Konus-Wind episode (Golenetskii et al., GCN 17108). The duration of the activity is about 200 s and clearly visible in SPI-ACS light curve. The start time of the maximal count rate of SPI-ACS light curve (binning with 50 s bin duration) is T0-725 s. In both cases TO and T0-725 s the boresight of SPI-ACS is the same and equal to 119 degrees. If this episode is related to the GRB 141121A and taking into account SPI-ACS energy threshold (>~ 80 keV) one can suggest the this episode of GRB 141121A is harder than main activity detected by BAT/Swift. We do not detect any significant activity at the time of the MAXI/GSC detection (Honda et al., GCN 17077). The SPI-ACS light curves can be found at http://grb.rssi.ru/GRB141121A/grb141121_spi-acs_50sec.png http://grb.rssi.ru/GRB141121A/grb141121_spi-acs_5sec.png
GCN 17111 table
GRB_name GRB141121A
GCN_number 17111
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17111 SUBJECT: GRB 141121A: Mondy optical observations DATE: 14/11/28 19:21:59 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy) on Nov., 27 starting (UT) 19:13:37. We obtained several images in R-filter ander favorable weather and mean FWHM of 1.8 arcsec. In a combined image we clearly detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). We do not detect the nearby source reported in (Watson et al., GCN 17075). Instead of we detect a Source (possible host?) 3 arcsec to the West from OT. The Source is absent in SDSS DR9. Coordinates of the OT and the Source are OT (J2000) 08 10 40.55 +22 13 03.0 with accuracy of 0.4" in both coordinates The Source to the West (J2000) 08 10 40.35 +22 13 03.0 with accuracy of 0.5" in both coordinates Astrometry solutions are based on USON-B1.0 catalog. A preliminary photometry of the OT is based on nearby SDSS stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-27 19:13:37 6.6923 R 72*120 21.57 0.05 And preliminary photometry of the Source is R 22.95 ± 0.11. The source is barely visible in our earlier observations (Mazaeva et al., GCN 17102) and photometry of the early observation reported in (Mazaeva et al., GCN 17102) might be biased of this Source. The finding chart can be found in http://grb.rssi.ru/GRB141121A/GRB141121A.Mondy_host_chart.png
GCN 17112 table
GRB_name GRB141121A
GCN_number 17112
Detection_method IPN Triangulation
ra 46.5430°
decl 16.6300°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17112 SUBJECT: IPN Triangulation of GRB 141121A (initial episode) DATE: 14/11/28 20:00:34 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, and A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The possible initial emission episode of GRB 141121A reported by Konus-Wind (Golenetskii et al., GCN Circ. 17108) has been also observed by INTEGRAL (SPI-ACS) and MESSENGER (GRNS) at about 13083 s UT (03:38:03; =T0(BAT)-760 s), so far. We have triangulated it to a INTEGRAL-MESSENGER annulus centered at RA(2000)=46.543 deg (03h 06m 10s) Dec(2000)=+16.630 deg (+16d 37' 49"), whose radius is 71.291 +/- 0.356 deg (3 sigma). The distance between the Swift-XRT position of GRB 141121A (Evans et al., GCN Circ. 17080) and the central line of the annulus is 32 arcsec, which strengthen the association of the episode with GRB 141121A. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB141121A/IPN/
GCN 17113 table
GRB_name GRB141121A
GCN_number 17113
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17113 SUBJECT: GRB 141121A: Khureltogot optical observations DATE: 14/11/28 22:40:39 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of We observed the field of GRB 141121A (Lien et al., GCN 17075) with ORI-40 telescope of Khureltogot observatory. We obtained several images in R-filter on Nov. 21 starting on (UT) 17:07:01. In a combined image we marginally detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). Preliminary photometry is following and based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-21 17:07:01 0.5977 R 120*60 19.0 0.3
GCN 17114 table
GRB_name GRB141121A
GCN_number 17114
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 17114 SUBJECT: GRB 141121A: MITSuME Ishigakijima Optical Observation after 7 days DATE: 14/11/29 02:41:50 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 and OISTER collaboration: We observed the field of GRB 141121A (Lien et al., GCNC 17075) 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 2014-11-28 15:13:00 (~7.5 days after the burst). We detected the previously reported afterglow (Tanga et al., GCNC 17078; Perley et al., GCNC 17081; Kuroda et al., GCNC 17091) in g' and Rc bands. Three sigma upper limit and photometric results of the OT are listed below. We used SDSS-DR7 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic -------------------------------------------------------------------------- 7.50078 15:51:50 2400.0 21.9 0.3 21.0 0.2 >20.5 -------------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 17116 table
GRB_name GRB141121A
GCN_number 17116
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17116 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/11/29 16:15:21 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 29.29 to 2014/11 29.53 UTC (195.13 to 200.87 hours after the BAT trigger), obtaining a total of 4.62 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 22.15 +/- 0.06 i = 21.97 +/- 0.06 z > 21.04 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The afterglow continues to fade with a steepening temporal index. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17117 table
GRB_name GRB141121A
GCN_number 17117
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17117 SUBJECT: GRB 141121A: TSHAO optical observations DATE: 14/11/29 18:03:22 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Kusakin (Fesenkov Astrophysical Institute), A. Volnova (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory starting on Nov. 26 (UT) 22:12:24. We obtained several images in R-filter. In a combined image we clearly detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry is based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-26 22:12:24 5.8118 R 14*300 21.48 0.09
GCN 17118 table
GRB_name GRB141121A
GCN_number 17118
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17118 SUBJECT: GRB 141121A: Mondy optical observations DATE: 14/11/30 14:40:57 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), E. Klunko (ISTP), A. Volnova (IKI), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy) Nov., 29 starting on (UT) 20:20:38. We obtained several images in R-filter under unfavorable seeing. In a combined image we detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry of the OT is based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-29 20:20:38 8.7458 R 84*120 22.03 0.17 Due to bad seeing the photometry above includes both afterglow and possible host (Watson et al., GCN 17105; Mazaeva et al., GCN 17111).
GCN 17119 table
GRB_name GRB141121A
GCN_number 17119
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17119 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/11/30 17:27:01 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/11 30.28 to 2014/11 30.54 UTC (218.99 to 225.08 hours after the BAT trigger), obtaining a total of 4.98 hours exposure in the r, i and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS DR9, we obtain the following detections and upper limits (3-sigma): r = 22.32 +/- 0.07 i = 22.14 +/- 0.07 z > 21.00 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17124 table
GRB_name GRB141121A
GCN_number 17124
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17124 SUBJECT: GRB 141121A: VLA radio detection DATE: 14/12/01 05:54:12 GMT FROM: Alessandra Corsi at Texas Tech U A. Corsi (Texas Tech U.) reports on behalf of a larger collaboration: We imaged the position of GRB 141121A (Lien et al., GCN 17075) with the Karl G. Jansky Very Large Array (VLA), at a mean epoch of about 8.4 days after the burst. We detect the radio afterglow of GRB 141121A (Anderson et al., GCN 17099; van der Horst, GCN 17104) at a position consistent with the optical counterpart (Tanga et al., GCN 17078). At this time, we estimate a preliminary flux of about 207 uJy at 14 GHz. The map rms is about 5 uJy.
GCN 17128 table
GRB_name GRB141121A
GCN_number 17128
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17128 SUBJECT: GRB 141121A: Continued RATIR Optical Observations DATE: 14/12/01 16:07:08 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2014/12 1.30 to 2014/12 1.54 UTC (243.35 to 249.19 hours after the BAT trigger), obtaining a total of 4.56 hours exposure in the r, i, and z bands. For a source within the Swift-XRT error circle, in comparison with the SDSS, we obtain the following detections and upper limits (3-sigma): r = 22.38 +/- 0.16 i = 22.21 +/- 0.16 z > 20.41 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Compared to our observations on previous nights (Watson et al., GCN 17116; Butler et al., GCN 17119), the fading appears to be slowing and is now behaving as t^-0.5. This may be evidence for an underlying host galaxy more closely coincident with the GRB than the candidate reported by Watson et al. (GCN 17105). We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 17138 table
GRB_name GRB141121A
GCN_number 17138
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17138 SUBJECT: GRB 141121A: Mondy optical observations DATE: 14/12/05 14:58:30 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We continue observations of the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy). We obtained several images in R-filter on Nov., 30, Dec. 1 - 2. In a combined image we detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry of the OT is based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-30 18:45:29 9.7139 R 119*120 22.20 0.10 2014-12-01 18:35:23 10.6644 R 72*120 22.25* 0.17 2014-12-02 18:09:52 11.6606 R 92*120 22.40* 0.25 *)Due to bad seeing the photometry includes both afterglow and nearby source (Watson et al., GCN 17105; Mazaeva et al., GCN 17111).
GCN 17145 table
GRB_name GRB141121A
GCN_number 17145
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17145 SUBJECT: GRB141121A: Discovery Channel Telescope Optical Observations DATE: 14/12/07 21:48:55 GMT FROM: Vicki Toy at UMD V. Toy (UMD), J. Capone (UMD), A. Cucchiara (NASA-GSFC), S.B. Cenko (NASA-GSFC), E. Troja (NASA-GSFC), A. Kutyrev (NASA-GSFC), and S. Veilleux (UMD) report on behalf of a larger collaboration: We observed the field of GRB141121A (Swift trigger 619182, Lien et al., GCN 17075) with the Large Monolithic Imager (LMI) on the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ from 2014/12/07 6:44 to 2014/12/07 11:01 UTC (starting 386.1 hours after the Swift trigger). A source is clearly detected at the location of the optical afterglow in g', r', i', and z'. Using nearby point sources from SDSS R8 for calibration we measure i' = 23.26 +/- 0.12. This magnitude is reported in AB magnitude and is not corrected for Galactic extinction in the direction of the GRB. Compared to RATIR observations on 12/01 (Watson, GCN 17128) the afterglow has steepened to a decay index of ~ t^-2.1. At this time we cannot confirm if this is the host galaxy. Further observations are planned. We thank the staff of the Discovery Channel Telescope for assistance with these observations.
GCN 17156 table
GRB_name GRB141121A
GCN_number 17156
Detection_method VLA Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17156 SUBJECT: GRB 141121A: further VLA observations DATE: 14/12/10 03:48:36 GMT FROM: Alessandra Corsi at Texas Tech U A. Corsi (Texas Tech U.), S.B. Cenko (NASA-GSFC), A. Cucchiara (NASA-GSFC), D. A. Perley (Caltech), A. Horesh (Weizmann Institute), D. A. Frail (NRAO) report: We imaged again the the position of GRB 141121A (Lien et al., GCN 17075) with the Karl G. Jansky Very Large Array (VLA), at a mean epoch of about 16.3 days after the burst. At this time, we detect the radio afterglow of GRB 141121A (Anderson et al., GCN 17099; van der Horst, GCN 17104; Corsi, GCN 17124), and estimate a preliminary flux of about 228 uJy at 6.2 GHz and 186 uJy at 14 GHz. The map rms is about 9 uJy at 6.2 GHz and 7 uJy at 14 GHz. Further observations are planned.
GCN 17191 table
GRB_name GRB141121A
GCN_number 17191
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17191 SUBJECT: GRB 141121A: Keck observations DATE: 14/12/18 12:15:16 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) reports: I observed the location of GRB 141121A (Lien et al., GCN 17075) using the imaging mode of the Low-Resolution Imaging Spectrometer (LRIS) on the Keck I 10-meter telescope between 10:55 and 11:16 UT on 2014-12-18. A short sequence of exposures in g, R, and i-bands was acquired. The optical counterpart (Tanga et al., GCN 17078) is clearly detected in all filters. Calibrating relative to SDSS, the magnitude is: i = 23.96 +/- 0.07 (t = 27.3 days) This measurement is significantly fainter than that reported by Toy et al. based on DCT observations on 2014-12-07, and the counterpart appears point-like in 0.8-arcsecond seeing. This suggests that the light is still dominated by the afterglow.
GCN 17284 table
GRB_name GRB141121A
GCN_number 17284
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17284 SUBJECT: Radio upper limit on the GRB 141121A with the GMRT DATE: 15/01/06 14:20:02 GMT FROM: Nayana A J at NCRA-TIFR A. J. Nayana (NCRA-TIFR) and Poonam Chandra (NCRA-TIFR) report: We carried out the Giant Metrewave Radio Telescope (GMRT) observations of GRB 141121A (GCN Circ 17075) in the 1390 MHz band on 2014 December 22h56m06s UT. We do not detect radio afterglow of the GRB in this frequency. The 3-sigma upper limit at the GRB position (GCN Circ. 17078) is 118 uJy. We thank GMRT staff for making these observations possible.
GCN 17656 table
GRB_name GRB141121A
GCN_number 17656
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17656 SUBJECT: GRB 141121A: GMG observation DATE: 15/03/30 06:23:44 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, Y. X. Xin, and J.-M. Bai (YNAO) report: We observed the field of GRB 141121A (Lien et al., GCN 17075) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatory. We obtain the following results of optical counterpart: Date begin UT r' begin UT i' Nov. 21, 2014 17:00:04 20.45+/-0.04 17:41:21 19.90+/-0.03 Nov. 22, 2014 17:57:44 22.46+/-0.09 18:38:40 21.89+/-0.08 Nov. 25, 2014 17:16:11 21.32+/-0.05 17:36:44 20.99+/-0.04 Nov. 27, 2014 18:28:57 22.60+/-0.08 18:49:23 21.99+/-0.05 Due to the poor seeing, we could not distinguish between the afterglow and the possible host galaxy. J. Mao apologizes for this very late GCN circular submission.
GCN 17108 table
GRB_name GRB141121A
GCN_number 17108
Detection_method Konus-Wind Det
t_trigger 3:36:13 UTC
redshift 1.4700
Circular_text TITLE: GCN CIRCULAR NUMBER: 17108 SUBJECT: Konus-Wind observation of GRB 141121A DATE: 14/11/28 14:34:54 GMT FROM: Dmitry Svinkin at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 141121A (Swift-BAT trigger #619182: Lien et al., GCN 17075; Krimm et al., GCN 17083; MAXI/GSC detection: Honda et al., GCN 17077) was detected by Konus-Wind in the waiting mode. The burst light curve shows two emission episodes. The first started at ~T0(BAT)-870 s with a duration of about 190 s and the second weaker episode, which corresponds to the first BAT episode reported in GCN 17075, started at ~T0(BAT)+50 s with a duration of about 270 s. The second BAT episode (from T0(BAT)+550 to T0(BAT)+675 s) is not seen in KW data. The first KW episode is likely related to GRB 141121A, since the KW ecliptic latitude response and IPN localization of the episode are consistent with the position of GRB 141121A. The details of the IPN localization will be given in a forthcoming GCN circular. During the first episode the burst source was outside the BAT FoV (private communication with the BAT team). The total burst duration is about 1200 s. Such a long duration and long periods of low-level emission or quiescence is common for ultra-long GRB. The KW light curve contains several data gaps. One of them (from ~T0(BAT)-670 s to ~T0(BAT)-270 s) may bias the estimated duration of the first episode. The MAXI/GSC detection at ~T0(BAT)-356 s falls into this gap. As observed by Konus-Wind, the first episode had a fluence of ~8x10^-6 erg/cm2 and a 2.944 s peak flux, measured from ~T0(BAT)-752 s, of ~2x10^-7 erg/cm2/s (both estimated in the 20 keV - 10 MeV energy range). The second episode had a fluence of ~6x10^-6 erg/cm2 estimated in the same energy range. Assuming the redshift z=1.47 (Perley et al., GCN 17081) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~8x10^52 erg, the peak luminosity L_iso is ~10^51 erg/s. The K-W light curve of this burst is available at http://www.ioffe.ru/LEA/GRBs/GRB141121A/