//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16878 SUBJECT: GRB 141004A: Swift detection of a burst with an optical counterpart DATE: 14/10/04 23:29:48 GMT FROM: David Palmer at LANL V. D'Elia (ASDC), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), L. Izzo (URoma/ICRA), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 23:20:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141004A (trigger=614390). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 76.730, +12.833 which is RA(J2000) = 05h 06m 55s Dec(J2000) = +12d 49' 59" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single FRED structure with a duration of about 8 sec. The peak count rate was ~17000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 23:21:54.2 UT, 59.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 76.73435, 12.81935 which is equivalent to: RA(J2000) = 05h 06m 56.24s Dec(J2000) = +12d 49' 09.7" with an uncertainty of 4.3 arcseconds (radius, 90% containment). This location is 51 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (3.14 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.3 (+5.50/-4.31) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 64 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 05:06:56.14 = 76.73391 DEC(J2000) = +12:49:11.3 = 12.81981 with a 90%-confidence error radius of about 0.61 arc sec. This position is 2.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.39 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.32. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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: 16879 SUBJECT: GRB 141004A: a long GRB detected by INTEGRAL DATE: 14/10/05 00:20:44 GMT FROM: Sandro Mereghetti at IASF/CNR S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), E.Bozzo, C.Ferrigno (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma-ray burst lasting about 10 s has been detected by IBAS in the IBIS/ISGRI data at 23:21:02 of October 4, 2014 The refined coordinates (J2000) are: R.A.= 76.7496 deg DEC.= +12.8235 deg with an uncertainty of 2 arcmin (90% c.l.). THis burst has also been detected by Swift (D'Elia et al. GCN 16878) A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16880 SUBJECT: GRB 141004A: 1.23m CAHA optical observations DATE: 14/10/05 01:02:09 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC/UPV-EHU), S. Hellmich (DLR), S. Mottola (DLR), on behalf of a larger collaboration report: We observed the GRB 141004A (D'Elia et al. GCN 16878) field with the 1.23m CAHA telescope. The observations were done in the Ic-band starting on Oct 4.9969 UT (34.6 minutes post GRB). A preliminary analysis detects a faint optical object located at (RA, DEC)=05:06:56.17, 12:49:10.8 (+/-0.7"), so consistent with the UVOT position. We estimate a preliminary Vega magnitude of Ic~19.2, calibrated against the USNO B1.0 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16881 SUBJECT: GRB 141004A: TNG photometric and spectroscopic observations DATE: 14/10/05 02:49:18 GMT FROM: Valerio D'Elia at ASDC V. D'Elia (INAF/OAR & ASI/ASDC), S. Covino (INAF/OAB), M. Cecconi and Carmen Padilla (INAF/TNG) report on behalf of the CIBO collaboration: We observed the optical afterglow of GRB 141004A (D'Elia et al., GCN 16878; Mereghetti et al. GCN 16879) on 2014 October 5 with the 3.6m TNG telescope located in the Canary Islands, equipped with the DOLORES operated in both imaging and spectroscopic mode. The observations were carried out under good weather conditions (seeing about 1.5) at high airmass. In a 180 s image started at 01:41 UT (~2.3 hr after the GRB), the afterglow has a magnitude r = 20.9 +/- 0.1 (AB), calibrated against the APASS catalog. No correction has been applied for the Galactic extinction. The position of the afterglow is RA: 05:06:56.17 Dec: 12:49:10.54, consistent with the UVOT detection (D'Elia et al. GCN 16878) and with the CAHA observation (Gorosabel et al., GCN 16880). We also detect a fainter object (possibly extended) 5" eastward to the afterglow. We also obtained two optical spectra, each one lasting 1200 s, using the grism LR-B covering the wavelength range 3000 - 8000 AA. The observations started at 01:00 UT (~1.7 hr after the GRB). Using a preliminary wavelength calibration, in the co-added spectrum we detect a faint continuum extending down to 4000 A. No obvious absorption or emission features are detected in our preliminary analysis of the afterglow spectrum. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16883 SUBJECT: GRB 141004A: Enhanced Swift-XRT position DATE: 14/10/05 06:33:18 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2078 s of XRT Photon Counting mode data and 2 UVOT images for GRB 141004A, 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 = 76.73357, +12.81944 which is equivalent to: RA (J2000): 05h 06m 56.06s Dec (J2000): +12d 49' 10.0" with an uncertainty of 1.6 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: 16886 SUBJECT: GRB 141004A: Monte Agliale Observatory optical observations DATE: 14/10/05 08:55:29 GMT FROM: Fabrizio Ciabattari at Monte Agliale Obs F. Ciabattari, S. Donati, E. Mazzoni, G. Petroni and M. Rossi (Monte Agliale Observatory, Borgo a Mozzano, Italy) report: We observed the field of GRB 141004A (D'Elia et al. GCN 16878) with the automatic 0.5m f/4.6 Newtonian telescope + FLI Proline PL4710 camera at Monte Agliale Observatory (Borgo a Mozzano, Italy, MPC code 159). The observations started at 2014-10-04 23:25:05 UT (~ 4 minutes after the burst trigger) and we co-added 19 unfiltered CCD exposures of 30 seconds each. We detect a new source of mag. R = 17.6 +/-0.2 (USNO-B1 catalogue, not corrected for Galactic extinction in the direction of the GRB) at the following position: R.A.(J2000) = 05h 06m 56.18s Dec.(J2000) = +12d 49' 10.9" FITS files are available on request from fabciaba@alice.it The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16887 SUBJECT: GRB 141004A: RATIR Optical Observations DATE: 14/10/05 09:34:12 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), 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), 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 141004A (D'Elia, et al., GCN 16878) 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 2014/10 5.30 to 2014/10 5.35 UTC (7.82 to 9.15 hours after the BAT trigger), obtaining a total of 1.07 hours exposure in the r and i bands. We detect the source reported by Swift/UVOT (D'Elia, et al., GCN 16878) and the 3.6m TNG telescope (D'Elia, et al., GCN 16881). We obtain the following detections: r 22.35 +/- 0.13 i 22.11 +/- 0.12 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the earlier TNG observations we note that the GRB has faded with an approximate temporal power-law index of t^(-1.0). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16890 SUBJECT: GRB 141004A: Swift/UVOT Detection DATE: 14/10/05 16:07:41 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 141004A 65 s after the BAT trigger (D'Elia et al., GCN Circ. 16878).The GRB was also detected by Integral (Mereghetti et al, GCN Circ. 16879), and in the optical by CAHA (Gorosabel et al, GCN Circ. 16880), TNG (D'Elia et al., GCN Circ. 16881), at Monte Agliale Observatory (Ciabatta et al. GCN Circ. 16886) and by RATIR (Littlejohns et al., GCN Circ. 16887). A source consistent with the XRT position (Osborne et al. GCN Circ. 16883) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 05:06:56.14 = 76.73393 (deg.) Dec (J2000) = +12:49:11.3 = 12.81981 (deg.) with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence). 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 65 215 147 17.64 +/- 0.07 v 606 1922 156 18.94 +/- 0.24 b 532 1156 58 18.94 +/- 0.20 u 277 527 246 17.93 +/- 0.09 w1 656 1453 97 18.67 +/- 0.24 m2 806 7273 216 >20.5 w2 582 13683 582 20.69 +/- 0.35 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.32 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16891 SUBJECT: GRB141004A: NOT imaging and spectroscopy DATE: 14/10/05 16:28:34 GMT FROM: Steve Schulze at U of Iceland S. Schulze (PUC, MAS), T. Kruehler (ESO Chile), D. Xu, J. P. U. Fynbo (DARK/NBI), N. R. Tanvir (U Leicester), P. Jakobsson (U. Iceland), S. Galleti (INAF-OAB) report on behalf a larger collaboration: We observed the field of GRB 141004A (D'Elia et al. GCN 16878, Mereghetti et al. GCN 16879) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. Observations started at 01:52:22 UT on October 5 (i.e., 2.52 hr after the burst). We obtained a 200-s image in the R band. The afterglow reported in D'Elia et al. (GCN 16878) and Gorosabel et al. (GCN 16880) is clearly detected. It has an R-band magnitude of 20.6 mag (not corrected for foreground extinction), calibrated against several USNO stars. The mid-exposure time is 2.55 hr after the trigger. Compared to D’Elia et al (GCN 16881), the brightness of the afterglow did not decrease. In addition, we obtained an optical spectrum, with a total exposure of 3 x 1800 s, using Grism #4 and covering the wavelength range 3750 - 9000 AA at a resolution of 17 AA. Observations started at 02:17:23 UT (i.e. 2.9 hr after the burst). The continuum is detected down to ~3750 AA. No absorption line is visible in the spectrum. A tentative emission line is detected at 5866.4 AA, which could be [OIII]-5007 at z=0.17 or [OII] at z=0.57. A higher S/N spectrum is needed to elucidate the nature of this feature. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16892 SUBJECT: GRB 141004A: Swift-BAT refined analysis DATE: 14/10/05 17:11:58 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), 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 141004A (trigger #614390) (D'Elia, et al., GCN Circ. 16878). The BAT ground-calculated position is RA, Dec = 76.721, 12.828 deg, which is RA(J2000) = 05h 06m 53.0s Dec(J2000) = +12d 49' 41.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single FRED peak starting with a weak emission at T-1 sec, the FRED peak starting at T_0.0, peaking at T+0.1 sec, and returning to baseline at ~T+20 sec. T90 (15-350 keV) is 3.92 +- 1.07 sec (estimated error including systematics). The time-averaged spectrum from T-0.84 to T+5.34 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.86 +- 0.08. The fluence in the 15-150 keV band is 6.7 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 6.1 +- 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/614390/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16896 SUBJECT: GRB 141004A: Swift-XRT refined Analysis DATE: 14/10/05 21:30:04 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), V. Mangano (PSU) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 7.1 ks of XRT data for GRB 141004A (D'Elia et al. GCN Circ. 16878), from 46 s to 54.0 ks after the BAT trigger. The data comprise 5 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 16883). The light curve can be modelled with an initial power-law decay with an index of alpha=0.66 (+0.08, -0.11), followed by a break at T+3318 s to an alpha of 1.9 (+0.7, -0.6). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.79 (+0.21, -0.12). The best-fitting absorption column is consistent with the Galactic value of 3.1 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.1 (+/-1.1) x 10^21 cm^-2 Galactic foreground: 3.1 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.79 (+0.21, -0.12) If the light curve continues to decay with a power-law decay index of 1.9, the count rate at T+24 hours will be 4.5 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-14 (2.6 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00614390. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16899 SUBJECT: GRB 141004A: GROND observations DATE: 14/10/06 19:23:19 GMT FROM: Sebastian Schmidl at TLS Tautenburg S. Schmidl (TLS Tautenburg), J. F. Graham, and J. Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 141004A (Swift trigger 614390; V. D'Elia et al., GCN #16878) 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). We detect the afterglow at the UVOT position reported by V. D'Elia et al. (GCN #16878). From coadded observations, starting on October 06 and spanning from 05:31 to 09:09 UT, we report the following preliminary AB magnitudes of: g' = 24.6 +/- 0.3, r' = 24.0 +/- 0.2, i' = 23.5 +/- 0.2, and z' = 23.4 +/- 0.2. Given magnitudes are calibrated against GROND zeropoints and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.32 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16900 SUBJECT: GRB 141004A: Fermi GBM observation DATE: 14/10/06 19:47:12 GMT FROM: Veronique Pelassa at UAH V. Pelassa (UAH) reports on behalf of the Fermi GBM Team: "At 23:20:54.42 UT on 4 October 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 141004A (trigger 434157657 / 141004973), which was also detected by the Swift/BAT (D'Elia et al. 2014, GCN 16878) and the INTEGRAL/IBIS (Mereghetti et al 2014, GCN 16879). The GBM on-ground location is consistent with the Integral position, which lies at an angle of 100.4 degrees from the Fermi LAT boresight. The GBM light curve consists of a short FRED peak followed by a faint tail with a duration (T90) of about 3 s (50-300 keV). The time-averaged spectrum from T0-0.320 s to T0+0.768 s (main peak) is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.3 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 147 +/- 28 keV (Castor stat 398.59 for 365 d.o.f.). The event fluence (10-1000 keV) in this time interval is (2.2 +/- 0.2)E-06 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.000 s in the 10-1000 keV band is 18 +/- 2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16902 SUBJECT: GRB141004A: Host galaxy redshift form GTC DATE: 14/10/07 10:39:48 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC), D. Malesani (DARK/NBI), S. Schulze (PUC, MAS), R. Sanchez-Ramirez (UPV/EHU, IAA-CSIC), J. Gorosabel (UPV/EHU, IAA-CSIC), C.A. Alvarez Iglesias (GTC, IAC), J. Molgo (GTC), and M. Rivero (GTC) report on behalf of a larger collaboration: We obtained spectroscopy of the optical counterpart of GRB 141004A (D'Elia et al., GCN 16878, Mereghetti et al., GCN 16879) with OSIRIS at the 10.4m GTC telescope on October 7, starting at 5:10 UT (~30 hr after the GRB). In a preliminary reduction of a 2x600 s exposure with the R1000R grism (covering from 5100 to 10000 A with a resolution of ~1000), we detected several emission lines corresponding to [O II], H-beta and [O III] at a common redshift of 0.573. This confirms that the tentative emission line detection reported by Schulze et al. (GCN 16891) was indeed real and that it corresponds to the [O II] 3727/3729 doublet. We also detect emission from another galaxy within the slit at a similar redshift of 0.571, with a projected distance of 22" to the East, which corresponds to ~150 kpc at that redshift, probably belonging to the same galaxy group. The nearby galaxy reported by D'Elia et al. (GCN 16881) shows multiple emission features at a redshift of 0.279, and it is therefore unrelated to the GRB. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16936 SUBJECT: GRB 141004A: La Palma late-time observations and possible brightening DATE: 14/10/20 21:09:31 GMT FROM: Steve Schulze at U of Iceland S. Schulze (PUC, MAS), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), K. Wiersema (U. Leicester), D. Xu (DARK/NBI), N. R. Tanvir (U. Leicester), D. Malesani, J. P. U. Fynbo (DARK/NBI), P. Jakobsson (U. Iceland), V. Nascimbeni (INAF/OAPd), J. Harmanen (NOT), and O. Vaduvescu (ING) report on behalf of a larger collaboration: We monitored the optical counterpart of GRB 141004A (D'Elia et al., GCN 16878; Mereghetti et al., GCN 16879) with the 2.5-m Nordic Optical Telescope (NOT), the 4.2-m William Herschel Telescope (WHT), and the 10.4-m Gran Telescopio Canarias (GTC). The latest NOT observation was secured with ALFOSC on October 14.17 (9.19 days after the burst) and consisted of 9x240-s in i' band. In the same night we obtained a deep 8x300-s image with ACAM mounted at the WHT in r' band starting at October 14.17. A GTC observation was secured on October 18.24 (13.27 days after the burst) and consisted of 3x180 s in r' band and 4x120 s in i' band. We applied differential photometry to check for variability using six unsaturated nearby stars. The transient did not change its brightness in r’ band by more than ~0.10 mag, but in the i' band our photometry indicates a tentative brightening by 0.46 +/- 0.27 mag. While the detected variability is only marginally significant, this behaviour is consistent with the emergence of a SN similar to SN 1998bw, both in terms of brightness and color evolution. We encourage further follow-up to test for the presence of an emerging SN. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16937 SUBJECT: GRB 141004A: RATIR Late Time Optical and NIR Observations DATE: 14/10/21 21:58:12 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), 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), 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 141004A (D'Elia, et al., GCN 16878) 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 2014/10 21.31 to 2014/10 21.51 UTC (392.08 to 396.95 hours after the BAT trigger), obtaining a total of 3.89 hours exposure in the r, i and z bands. We continue to detect the source reported from the previous epoch of RATIR observations (Littlejohns, et al., GCN 16887). We obtain the following detections and upper limit (3-sigma): r 24.21 +/- 0.24 i 23.24 +/- 0.14 z > 21.47 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. These magnitudes suggest the source to remain brighter than expected if determined purely from a typical GRB power-law decay. This may corroborate the claim of re-brightening (Schulze, et al., GCN 16936), however, it may also indicate the detection of the host galaxy (de Ugarte Postigo, et al., GCN 16902). We also note that these magnitudes are broadly consistent with those observed by GROND at an approximate epoch of 32 hours after the initial Swift/BAT trigger (Schmidl, et al., GCN 16899). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16963 SUBJECT: GRB 141004A: Continued RATIR Late Time Optical and NIR Observations DATE: 14/10/26 19:23:33 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), 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), 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 again observed the field of GRB 141004A (D'Elia, et al., GCN 16878) 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 2014/10 26.26 to 2014/10 26.52 UTC (21.27 to 21.55 days after the BAT trigger), obtaining a total of 4.98 hours exposure in the r, i and z bands. We continue to detect the source reported in previous epochs of RATIR observations (Littlejohns, et al., GCN 16937, Littlejohns, et al., GCN 16887), with the following detections and upper limit: r 23.94 +/- 0.20 i 23.38 +/- 0.15 z > 20.97 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. These magnitudes are broadly consistent with our previous epoch of observations (Littlejohns, et al., GCN 16937). Further observations are planned. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17003 SUBJECT: GRB 141004A: Continued Late Time RATIR Optical and NIR Observations DATE: 14/10/31 18:59:43 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), 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), 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 again observed the field of GRB 141004A (D'Elia, et al., GCN 16878) 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 2014/10 31.31 to 2014/10 31.46 UTC (26.34 to 26.48 days after the BAT trigger), obtaining a total of 2.84 hours exposure in the r, i and z bands. We continue to detect the source reported from previous epochs of RATIR observations (Littlejohns, et al., GCN 16963; GCN 16937; GCN 16887). We obtain the following detections and upper limit (3 sigma): r 23.62 +/- 0.19 i 23.17 +/- 0.15 z > 21.09 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to our previous epochs of observations, the source appears to have brightened in the r and i bands, consistent with an emerging supernova similar to SN 1998bw (Schulze, et al., GCN 16936). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.