GRB150910A

This page lists all entries on GRB150910A in GRBweb

Summary IPN Swift GCN 18264 GCN 18265 GCN 18266 GCN 18267 GCN 18268 GCN 18269 GCN 18270 GCN 18271 GCN 18272 GCN 18273 GCN 18274 GCN 18275 GCN 18276 GCN 18277 GCN 18278 GCN 18279 GCN 18281 GCN 18284 GCN 18285 GCN 18287 GCN 18288 GCN 18289 GCN 18295 GCN 18301 GCN 18302 GCN 18306 GCN 18312 GCN 18314 GCN 18319 GCN 18320 GCN 18327 GCN 18556

Summary table
Variable Value Source
T0 9:04:48 UTC GCN_circulars,Swift Det
ra 5.6671° Swift
decl 33.4727° Swift
pos_error 7.51e-05° Swift
T90 112.2 s Swift
T90_start 9:04:48 UTC Swift
fluence 4.80e-06 erg/cm² Swift
redshift 1.3590
T100 112.2 s
GBM_located False
mjd 57275.378333333334 GCN_circulars,Swift Det
IPN table
GRB_name GRB150910A
ra 5.6750°
decl 33.5000°
pos_error 5.00e-02°
redshift 1.3590
Swift table
GRB_name GRB150910A
t_trigger 9:04:48 UTC
ra 5.6671°
decl 33.4727°
pos_error 7.51e-05°
T90 112.2 s
fluence 4.80e-06 erg/cm²
redshift 1.3590
GCN 18264 table
GRB_name GRB150910A
GCN_number 18264
Detection_method Swift Det
t_trigger 9:04:48 UTC
ra 5.6750°
decl 33.4990°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18264 SUBJECT: GRB 150910A: Swift detection of a burst with an optical afterglow DATE: 15/09/10 09:26:53 GMT FROM: Kim Page at U.of Leicester C. Pagani (U Leicester), A. P. Beardmore (U Leicester), A. A. Breeveld (UCL-MSSL), K. L. Page (U Leicester), P. Romano (INAF-IASFPA) and T. N. Ukwatta (LANL) report on behalf of the Swift Team: At 09:04:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150910A (trigger=655097). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 5.675, +33.499 which is RA(J2000) = 00h 22m 42s Dec(J2000) = +33d 29' 55" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for image triggers, the real-time light curve does not show anything significant. The XRT began observing the field at 09:07:14.1 UT, 145.3 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 5.6669, 33.4717 which is equivalent to: RA(J2000) = +00h 22m 40.06s Dec(J2000) = +33d 28' 18.1" with an uncertainty of 5.1 arcseconds (radius, 90% containment). This location is 101 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 153 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 00:22:40.14 = 5.66723 DEC(J2000) = +33:28:21.9 = 33.47275 with a 90%-confidence error radius of about 0.71 arc sec. This position is 3.9 arc sec. from the center of the XRT error circle. The estimated magnitude is 20.27 with a 1-sigma error of about 0.18. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05. Burst Advocate for this burst is C. Pagani (cp232 AT star.le.ac.uk). 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 18265 table
GRB_name GRB150910A
GCN_number 18265
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18265 SUBJECT: GRB 150910A: KAIT Optical Afterglow Detection DATE: 15/09/10 10:00:52 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 150910A (Pagani et al., GCN 18264) starting at 09:34:20 UT, ~30 minutes after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. The UVOT afterglow reported by Pagani et al. (GCN 18264) was clearly detected in all filters. The brightness is about R~16.2 mag at ~30 minutes after the burst, and is decreasing. Follow-up observations are encouraged.
GCN 18266 table
GRB_name GRB150910A
GCN_number 18266
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18266 SUBJECT: GRB 150910A: LCOGT FTN afterglow observations DATE: 15/09/10 11:05:14 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy S. Dichiara, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana), C. Mundell (U. Bath) on behalf of a larger collaboration report: The 2-m LCOGT Faulkes Telescope North in Hawaii began observing Swift GRB 150910A (Pagani et al. GCN 18264) on September 10, 09:33:19 UT (28 minutes after the burst trigger) with SDSS r and i filters. We clearly detect the optical afterglow (Pagani et al. GCN 18264; Zheng et al. GCN 18265) with the following magnitudes: Mid Time Exposure Filter Magnitude (min) (s) ------------------------------------------------------- 29.0 60 r' 16.60 +- 0.02 35.6 60 i' 16.42 +- 0.02 ------------------------------------------------------- Calibration is done against SDSS magnitudes of nearby stars.
GCN 18267 table
GRB_name GRB150910A
GCN_number 18267
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 18267 SUBJECT: GRB 150910A: MITSuME Okayama Optical Observation DATE: 15/09/10 11:41:03 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (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 150910A (Pagani et al., GCNC 18264) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2015-09-10 10:20:44 UT (~1.3 h after the burst). We detected the previously reported afterglow (Pagani et al., GCNC 18264; Zheng and Filippenko, GCNC 18265; Dichiara et al., GCNC 18266) 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 ----------------------------------------------------------------------- 0.05630 10:25:52 540.0 17.6 0.2 18.4 0.2 17.0 0.1 ------------------------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 18268 table
GRB_name GRB150910A
GCN_number 18268
Detection_method Swift-BAT Det
ra 5.6770°
decl 33.4660°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18268 SUBJECT: GRB 150910A: Swift-BAT refined analysis DATE: 15/09/10 13:19:46 GMT FROM: Scott Barthelmy at NASA/GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), C. Pagani (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), 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 downlinks, we report further analysis of BAT GRB 150910A (trigger #655097) (Pagani, et al., GCN Circ. 18264). The BAT ground-calculated position is RA, Dec = 5.677, 33.466 deg, which is RA(J2000) = 00h 22m 42.5s Dec(J2000) = +33d 27' 56.8" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 14%. The mask-weighted light curve shows the burst definitely starting at ~T-150 sec (and posibly before T-240 when we start having data), peaking at ~T+83 sec, and ending at ~T+450 sec. T90 (15-350 keV) is 112.2 +- 38.3 sec (estimated error including systematics). The time-averaged spectrum from T-5.00 to T+149.75 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.42 +- 0.12. The fluence in the 15-150 keV band is 4.8 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+82.89 sec in the 15-150 keV band is 1.1 +- 0.4 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/655097/BA/
GCN 18269 table
GRB_name GRB150910A
GCN_number 18269
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18269 SUBJECT: GRB 150910A: Nanshan optical observations DATE: 15/09/10 14:50:26 GMT FROM: Dong Xu at NAOC/CAS D. Xu (NAOC/CAS), Y. Qin (Geneva Observatory), Y.-D. Hu (IAA-CSIC), Y.-H. Han (NAOC/CAS, HUST), X. Zhang, A. Esamdin, L. Ma (XAO) report: We observed the field of GRB 150910A (Pagani et al., GCN 18264) using the 1m telescope located at Nanshan, Xinjiang, China. We obtained 3x600s R-band frames with some floating clouds in the sky. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is detected in each of the frames. Preliminary results are as follows Mid Time Exposure Mag MagErr (hr) (s) 4.91 600 19.40 0.20 5.14 600 19.55 0.20 5.31 600 19.30 0.20 and calibrated with the nearby SDSS field.
GCN 18270 table
GRB_name GRB150910A
GCN_number 18270
Detection_method Swift-UVOT Det
ra 5.6671°
decl 33.4727°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18270 SUBJECT: GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow DATE: 15/09/10 16:11:49 GMT FROM: Marissa McCaule at PSU L. M. McCauley (PSU) and C. Pagani (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150910A 154 s after the BAT trigger (Pagani et al., GCN Circ. 18264). A source consistent with the XRT position (Pagani et al. GCN Circ. 18264) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 00:22:40.11 = 5.66713 (deg.) Dec (J2000) = +33:28:21.9 = 33.47274 (deg.) with an estimated uncertainty of 0.58 arc sec. (radius, 90% confidence). Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) show a very rapid and steep rise in the luminosity of the afterglow over the first 1 ks of observation. Further investigation is strongly encouraged. Preliminary detections for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 153 303 147 19.90 white 156 303 144 19.93 white 592 612 19 17.09 white 765 785 19 16.67 white 866 1016 147 16.30 v 135 145 9 >17.23 v 642 662 19 16.64 v 815 835 19 16.91 v 1046 1066 19 16.11 b 568 588 19 17.56 b 741 761 19 16.87 u 312 561 245 18.03 u 312 561 245 18.02 u 716 736 19 16.14 uvw1 692 712 19 16.76 uvw2 1022 1041 19 >17.97 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 18271 table
GRB_name GRB150910A
GCN_number 18271
Detection_method Swift-XRT Det
ra 5.6672°
decl 33.4728°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18271 SUBJECT: GRB 150910A: Enhanced Swift-XRT position DATE: 15/09/10 19:10:24 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 1428 s of XRT Photon Counting mode data and 5 UVOT images for GRB 150910A, 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 = 5.66723, +33.47278 which is equivalent to: RA (J2000): 00h 22m 40.14s Dec (J2000): +33d 28' 22.0" with an uncertainty of 1.4 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 18272 table
GRB_name GRB150910A
GCN_number 18272
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18272 SUBJECT: GRB 150910A: Swift-XRT refined Analysis DATE: 15/09/10 22:26:03 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU) and C. Pagani report on behalf of the Swift-XRT team: We have analysed 8.0 ks of XRT data for GRB 150910A (Pagani et al. GCN Circ. 18264), from 136 s to 35.1 ks after the BAT trigger. The data comprise 938 s in Windowed Timing (WT) mode (the first 7 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. 18271). The late-time light curve (from T0+6.4 ks) can be modelled with a series of power-law decays. The initial decay index is alpha=0.67 (+0.23, -0.21). At T+10.9 ks the decay steepens to an alpha of 3.17 (+0.86, -0.30) before breaking again at T+20.3 ks to a final decay with index alpha=1.3 (+/-0.4). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.56 (+/-0.04). The best-fitting absorption column is 1.30 (+0.16, -0.15) x 10^21 cm^-2, in excess of the Galactic value of 5.4 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.77 (+0.09, -0.08) and a best-fitting absorption column of 7.1 (+2.3, -1.7) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 7.1 (+2.3, -1.7) x 10^20 cm^-2 Galactic foreground: 5.4 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.77 (+0.09, -0.08) If the light curve continues to decay with a power-law decay index of 1.3, the count rate at T+24 hours will be 0.033 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-12 (1.4 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/00655097. This circular is an official product of the Swift-XRT team.
GCN 18273 table
GRB_name GRB150910A
GCN_number 18273
Detection_method Optical
redshift 1.3590
Circular_text TITLE: GCN CIRCULAR NUMBER: 18273 SUBJECT: GRB 150910A: Kast spectroscopy from 3m Shane telescope DATE: 15/09/11 00:05:09 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng, Alexei V. Filippenko and Heechan Yuk (UC Berkeley), Yinan Zhu (NAOC) and Daniel A. Perley (Dark Cosmology Center) report on behalf of the KAIT GRB team: We observed the optical afterglow of GRB 150910A (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) with the Kast spectrograph on the 3m Shane telescope at Lick Observatory, started at 10:08 UT (about 1.1 hours after the burst), covering the 3500 - 10000 A wavelength range. A 1200-second and a 2400-second exposures were acquired. The spectrum shows blue continuum flux across the entire spectral range. We detect absorption lines from Mg II (2796,2803) and Fe II (2344,2374,2383) at a common redshift of z=1.359, as well as additional lines further to the blue. We suggest this as the likely redshift of the GRB.
GCN 18274 table
GRB_name GRB150910A
GCN_number 18274
Detection_method Other
redshift 1.3600
Circular_text TITLE: GCN CIRCULAR NUMBER: 18274 SUBJECT: GRB 150910A: Redshift from 10.4m GTC+OSIRIS DATE: 15/09/11 00:17:10 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC Antonio de Ugarte Postigo (IAA-CSIC, DARK/NBI), Christina Thoene (IAA-CSIC), Gianluca Lombardi (IAC, ULL, GRANTECAN), and Alberto Perez (GRANTECAN) report on behalf of a larger collaboration: We have observed the afterglow of GRB 150910A (Pagani et al., GCN 18264) using the 10.4 m GTC telescope equipped with OSIRIS. Our observation began at 23:11 UT (14.1 hr after the burst) and consisted of 3x900s exposures using the R1000B grism. The spectrum covers the wavelength range between 3700 and 7800 AA. The acquisition image shows the afterglow at a magnitude of r=20.65+/-0.07 as compared to SDSS stars. The first spectrum shows a continuum throughout the full spectral range, with several absorption features that correspond to AlII, AlIII, FeII, MgII and MgI at a common redshift of 1.360, which we interpret as the redshift of the GRB.
GCN 18275 table
GRB_name GRB150910A
GCN_number 18275
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18275 SUBJECT: GRB 150910A: SAO RAS optical photometry DATE: 15/09/11 02:06:57 GMT FROM: Moskvitin Alexander at SAO RAS A.S.Moskvitin (SAO RAS), V.P.Goranskij (SAI, Moscow State University), report on behalf of larger GRB follow-up team: We observed the field of the GRB 150910A (Pagani et al., GCN #18264) with the Zeiss-1000, 1-meter telescope of SAO RAS (Russia), equipped with the broadband filters UBVRcIc and EEV 42-40 CCD. The observations started since 10.85 hours after the trigger. We obtained sets of 6 x 300-sec. frames in Rc band three times per September, 10/11 night. The OT (reported by Pagani et al., GCN #18264; Zheng & Filippenko, GCN #18265; Dichiara et al., GCN #18266; Kuroda et al., GCN #18267; Xu et al., GCN #18269; McCauley & Pagani, GCN #18270; Zheng et al., GCN #18273; de Ugarte Postigo et al., GCN #18274) is clearly visible even in single frames. The results of observations are as following. # (T_mid-T0),h exp.,s R_mag time, UT 1. 11.035 6 x 300 20.20 +/- 0.05 19:56:03--20:17:48 2. 13.448 6 x 300 20.57 +/- 0.05 22:15:17--22:48:09 3. 15.739 6 x 300 20.78 +/- 0.05 00:32:30--01:05:46 Photometry is based on nearby SDSS stars (their magnitudes were converted with the Lupon 2005 equations).
GCN 18276 table
GRB_name GRB150910A
GCN_number 18276
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 18276 SUBJECT: GRB 150910A: MITSuME Ishigakijima Optical Observation DATE: 15/09/11 04:46:31 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 150910A (Pagani et al., GCNC 18264) 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 2015-09-10 12:21:44 UT (~3.3 h after the burst). We detected the previously reported afterglow (Pagani et al., GCNC 18264; Zheng and Filippenko, GCNC 18265; Dichiara et al., GCNC 18266; Kuroda et al., GCNC 18267) in all the three bands. Photometric results of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err ----------------------------------------------------------------------- 0.14010 12:26:33 540.0 19.1 0.1 18.8 0.1 18.4 0.1 ----------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 18277 table
GRB_name GRB150910A
GCN_number 18277
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 18277 SUBJECT: GRB 150910A: GROND observation of the afterglow DATE: 15/09/11 08:30:45 GMT FROM: Sebastian Schmidl at TLS Tautenburg S. Schmidl (TLS Tautenburg), F. Knust, and J. Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 150910A (SWIFT trigger 655097; Pagani et al, GCN 18264) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile). Observations started on September 11, 2015, at 05:08 UT, 20.1 hrs after the GRB trigger. They were performed at an average seeing of 2.8" and at an average airmass of 2.2. We clearly detect the optical afterglow reported by Pagani et al. (GCN 18264), Zheng & Filippenko (GCN 18265), Dichiara et al. (GCN 18266), Kuroda et al. (GCN 18267), Xu et al. (GCN 18269), de Ugarte Postigo et al. (GCN 18274) and Moskvitin et al (GCN 18275). Based on total exposures of 7.7 minutes in g'r'i'z'and 4.0 minutes in JHK, at a midtime of 20.8 hrs after the burst, we measure the following preliminary magnitudes (AB magnitude system): g' = 21.5 +/- 0.2 mag, r' = 21.2 +/- 0.2 mag, i' = 21.0 +/- 0.2 mag, z' = 20.8 +/- 0.2 mag, J > 19.8 mag, H > 19.3 mag, and K > 18.1 mag. Given magnitudes and upper limits are calibrated against SDSS as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.05 mag in the direction of the burst (Schlegel et al. 1998).
GCN 18278 table
GRB_name GRB150910A
GCN_number 18278
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 18278 SUBJECT: GRB 150910A: MITSuME Okayama Ks-band Observation DATE: 15/09/11 09:07:35 GMT FROM: Kenshi Yanagisawa at OAO/NAOJ Kenshi Yanagisawa, Daisuke Kuroda, Yasuhiro Shimizu, Hideyuki Izumiura (OAO/NAOJ), Michitoshi Yoshida (Hiroshima-U), Kouji Ohta(Kyoto-U), and Nobuyuki Kawai(Tokyo Tech.) report on behalf of the MITSuME collaboration: We observed the field of GRB150910A (Pagani et al., GCNC 18264) in Ks-band with a wide-field NIR camera at Okayama Astrophysical Observatory (Japan). The camera has an effective aperture of 0.91m. Observations started from 10:03 UT on 10th September, 59 min after the BAT trigger, to 11:14 UT. The total exposure of 26 min was successfully obtained. In our co-add image, we found a single point source at R.A.(J2000) = 00:22:39.84 DEC (J2000) = +33:28:20.5 with an uncertainty of of about 2 arcsec. We estimate the magnitude Ks = 14.85 +/- 0.13 (Vega). The calibration was made against 2MASS field stars. T0+[min] MID-UT T-EXP[min] Ks ------------------------------------------------------------ +94 10:38 26 14.85 +/- 0.13 (Vega) ------------------------------------------------------------ T0+ : Elapsed time after the burst [min] T-EXP: Total Exposure time [min]
GCN 18279 table
GRB_name GRB150910A
GCN_number 18279
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18279 SUBJECT: GRB 150910A: NOT observations of the afterglow DATE: 15/09/11 13:06:31 GMT FROM: Zach Cano at U of Iceland Z. Cano (U. Iceland), D. Malesani (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Xu (NAOC/CAS), J. Saario (NOT, U. Turku) and P. Jakobsson (U. Iceland) report on behalf of a larger collaboration: We observed the field of GRB 150910A (Pagani et al., GCN Circ. 18264) with the 2.5-m Nordic Optical Telescope (NOT) equipped with MOSCA in two epochs on the morning of 11-Sept-2015, at 01:10 and 04:45 UT, respectively. In SDSS filters r (epoch 1) and ugrz (epoch 2) we clearly detect the optical afterglow (e.g. Zheng & Filippenko, GCN Circ. 18265). A summary of our photometry is as follows: ------------------------------------------------------- filter (SDSS) t-t0 (hr) mag +- merr ------------------------------------------------------- r 16.27 20.85 +- 0.18 r 20.18 21.24 +- 0.21 u 20.05 21.82 +- 0.24 g 20.24 21.49 +- 0.22 z 19.84 20.78 +- 0.24 These magnitudes are calibrated to SDSS and are not corrected for foreground extinction. We note that these magnitudes are in good agreement with those obtained by GROND (Schmidl et al., GCN Circ. 18277) at a contemporaneous post-explosion epoch. Compared with other datasets, e.g. Xu et al. (GCN Circ. 18269), our second epoch of r-band observations implies a power-law like decay in time, e.g. f(t)=t^-alpha, with a decay slope of alpha=1. ​1.
GCN 18281 table
GRB_name GRB150910A
GCN_number 18281
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18281 SUBJECT: GRB 150910A: TSHAO optical observations DATE: 15/09/11 19:27:21 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Kusakin (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory on Sep. 10 (UT) 18:02:59 -- 20:37:38. We obtained several images in R and B filters. In both filters the afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly visible. Within 2.5 hours of observations we do not detect significant fading of the afterglow. The photometry of combined images are following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-10 18:08:20 0.42807 R 11*300 20.18 +/- 0.05 2015-09-10 18:02:59 0.42436 B 12*300 20.85 +/- 0.08 The photometry is based on nearby SDSS stars SDSS_id R(Lupton) J002232.47+332751.3 16.29 J002236.24+332854.2 15.92 J002241.61+332836.1 16.23 J002248.33+332723.4 16.76 J002231.90+333004.8 16.93 J002225.39+332809.6 16.12 J002246.76+332716.9 17.63 Our photometry in R-filter is in agreement with in subsequent observations (Moskvitin & Goranskij, GCN 18275).
GCN 18284 table
GRB_name GRB150910A
GCN_number 18284
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18284 SUBJECT: GRB 150910A: continued SAO RAS optical observations DATE: 15/09/11 22:20:23 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin (SAO RAS), report on behalf of larger GRB follow-up team: The field of the GRB 150910A (Pagani et al., GCN #18264) was observed with the Zeiss-1000 telescope of SAO RAS (Russia) in Rc band on September, 11.791 (T_mid-T0 = 1.413 days), 17:55:54--20:01:44 UT. 20 x 300 seconds frames were obtained. The OT is still clearly visible in the stacked image. The brightness of the object R = 22.2 +/- 0.10 (based on the same SDSS stars as in previous circular GCN #18275).
GCN 18285 table
GRB_name GRB150910A
GCN_number 18285
Detection_method VLA Det
ra 5.6672°
decl 33.4727°
Circular_text TITLE: GCN CIRCULAR NUMBER: 18285 SUBJECT: GRB 150910A: VLA Detection DATE: 15/09/11 22:54:59 GMT FROM: Kate Alexander at Harvard K. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger (Harvard) report on behalf of a larger collaboration: We observed GRB 150910A (Pagani et al; GCN 18264) at multiple frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2015 September 11.10 UT (0.72 days after the burst). At a mean frequency of 9.8 GHz, we detect a radio source with a preliminary flux density of ~ 0.1 mJy at RA = 00:22:40.120 +/- 0.021 Dec = +33:28:21.750 +/- 0.036 consistent with the UVOT optical position (McCauley et al; GCN 18270) and the enhanced Swift/XRT position (Evans et al.; GCN 18271). Follow-up observations are planned.
GCN 18287 table
GRB_name GRB150910A
GCN_number 18287
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18287 SUBJECT: GRB 150910A: Chuguev observatory optical observations DATE: 15/09/12 02:51:11 GMT FROM: Alexei Pozanenko at IKI, Moscow Yu. Krugly (IA KhNU), E. Mazaeva (IKI), V. Shevchenko (IA KhNU), T. Gromakina (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with 0.7m telescope of Institute of Astronomy, Kharkiv National University starting on Sep. 10 (UT) 21:41:15. We obtained several images in R B filter. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly visible in a combined image. The photometry of the combined image is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-10 21:41:15 0.52235 R 11*180 20.25 +/-0.14 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)
GCN 18288 table
GRB_name GRB150910A
GCN_number 18288
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 18288 SUBJECT: GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day DATE: 15/09/12 02:51:13 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 150910A (Pagani et al., GCNC 18264) 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 2015-09-11 12:29:42 UT (~1.14 days after the burst). We detected the previously reported afterglow (Pagani et al., GCNC 18264; Zheng and Filippenko, GCNC 18265; Dichiara et al., GCNC 18266; Kuroda et al., GCNC 18267) in g' and Rc bands. Photometric results and three sigma upper limit of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err ----------------------------------------------------------------------- 1.21526 14:14:46 4800.0 21.8 0.2 21.2 0.2 >20.8 ----------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 18289 table
GRB_name GRB150910A
GCN_number 18289
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18289 SUBJECT: GRB 150910A: AAO optical observations DATE: 15/09/12 03:14:23 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), V. Zhuzhunadze (AAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with with AS-32 (0.7m) telescope of Abastumani Observatory starting on Sep. 10 (UT) 18:53:54. We obtained several unfiltered images. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly visible in a combined image. The photometry of the combined image is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-10 18:53:54 0.45834 none 50*120 20.16 +/- 0.06 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)
GCN 18295 table
GRB_name GRB150910A
GCN_number 18295
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18295 SUBJECT: GRB150910A: P60 Observations DATE: 15/09/12 16:15:10 GMT FROM: Daniel Perley at Caltech D. A. Perley (DARK) and S. B. Cenko (NASA/GSFC) report: We observed the location of GRB 150910A (Pagani et al., GCN 18264) using the robotic Palomar 60-inch telescope on two epochs during the night of 2015-09-11 UT, and an additional epoch during the night of 2015-09-12 UT. During each epoch we acquired 3x180s of imaging in each of the g', r', and i' filters. The optical afterglow (Pagani et al.; Zheng and Filippenko, GCN 18265) is detected in each observation. Preliminary photometry relative to SDSS yields: t_start(d) filt mag emag 0.973 i = 21.24 +/- 0.12 0.980 g = 21.54 +/- 0.06 0.989 r = 21.35 +/- 0.08 1.067 i = 21.28 +/- 0.07 1.074 g = 21.85 +/- 0.06 1.081 r = 21.50 +/- 0.06 2.060 i = 22.21 +/- 0.17 2.067 g = 22.66 +/- 0.14 2.074 r = 23.03 +/- 0.26
GCN 18301 table
GRB_name GRB150910A
GCN_number 18301
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 18301 SUBJECT: GRB 150910A: MITSuME Ishigakijima Optical Observation after 2 days DATE: 15/09/13 00:03:14 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 150910A (Pagani et al., GCNC 18264) 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 2015-09-12 13:59:26 UT (~2.2 days after the burst). We detected the previously reported afterglow (Pagani et al., GCNC 18264; Zheng and Filippenko, GCNC 18265; Dichiara et al., GCNC 18266; Kuroda et al., GCNC 18267) in Rc band. Photometric results and three sigma upper limit of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic ----------------------------------------------------------------------- 2.22658 14:31:04 3240.0 >22.4 22.3 0.4 >20.73 ----------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]
GCN 18302 table
GRB_name GRB150910A
GCN_number 18302
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 18302 SUBJECT: GRB 150910A: RATIR Observations DATE: 15/09/13 16:22:24 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), 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), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 150910A (Pagani et al., GCN 18264) 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 2015/09 13.15 to 2015/09 13.26 UTC (66.44 to 69.21 hours after the BAT trigger), obtaining a total of 0.99 hours exposure in the r, i, and z bands. The optical afterglow (Pagani et al.; Zheng and Filippenko, GCN 18265) is well detected. In comparison with the SDSS DR9 catalog, we obtain: r 22.44 +/- 0.13 i 22.31 +/- 0.11 z > 20.29 (3-sigma) 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 18306 table
GRB_name GRB150910A
GCN_number 18306
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18306 SUBJECT: GRB 150910A: Mt. Terskol observatory optical observation DATE: 15/09/14 07:16:41 GMT FROM: Alexei Pozanenko at IKI M. Andreev (Terskol Branch of INASAN), E. Mazaeva (IKI), A. Sergeev (Terskol Branch of INASAN), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with Zeiss-600 telescope of Mt. Terskol observatory in R-filter starting on Sep. 10 (UT) 20:45:05. We obtained several unfiltered images. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly detected in a combined image. The photometry of the combined image is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-10 20:45:05 0.51974 R 46*120 20.46 +/- 0.07 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)
GCN 18312 table
GRB_name GRB150910A
GCN_number 18312
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 18312 SUBJECT: GRB 150910A: Continued RATIR Observations DATE: 15/09/14 17:25:20 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), 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), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 150910A (Pagani et al., GCN 18264) 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 2015/09 14.17 to 2015/09 14.46 UTC (90.88 to 98.01 hours after the BAT trigger), obtaining a total of 1.71 hours exposure in the r, i, and z bands. The optical afterglow (Pagani et al.; Zheng and Filippenko, GCN 18265) is well detected. In comparison with the SDSS DR9 catalog, we obtain: r = 22.23 +/- 0.09 i = 22.44 +/- 0.10 z > 19.89 (3-sigma) These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Compared to our previous night of observations (Butler et al., GCN 18302), the source flux is consistent with remaining constant at the ~1-sigma level. Also, the source appears to be extended in our images, suggesting that the flux may be dominated by the GRB host galaxy. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 18314 table
GRB_name GRB150910A
GCN_number 18314
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 18314 SUBJECT: GRB 150910A: T100 observations DATE: 15/09/15 08:24:52 GMT FROM: Eda Sonbas at NASA/GSFC E. Sonbas (Adiyaman Univ.), O. Basturk (Ankara Univ.), T. Guver (Istanbul Univ.), E. Gogus (Sabanci Univ.), S. Eryilmaz, O. Erece, H. Kirbiyik (TUG) report on behalf of a larger collaboration We observed the field of Swift GRB 150910A (Pagani et al., GCN#18264) with the 1.0 meter T100 telescope (Bakirlitepe, TUBITAK National Observatory, Turkey), starting September, 10, 20:08:16 UT (~ 11 hours after the trigger). Observations were carried out in the R filter. The afterglow is detected in the R band images with an exposure time of 300 s. Using USNO-B1 star USNO-B1 1234-0008068 (R.A.=5.65, Dec=+33.45) in the field, the magnitudes of the OT were estimated as follows; t-t0 (hr) exp.(s) filt mag err (+/-) 10.97 300 R 20.09 0.23 11.06 300 R 20.18 0.25 Analysis of further observations with the same filter is ongoing. We thank to TUBITAK National Observatory for a partial support in using T100 telescope with project number 10CT100-95 and technical support.
GCN 18319 table
GRB_name GRB150910A
GCN_number 18319
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18319 SUBJECT: GRB 150910A: TSHAO optical observations DATE: 15/09/16 11:35:17 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 150910A (Pagani et al., GCN 18264) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory on Sep. 11 and Sep. 12. We obtained several images in R filter. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly visible in a combined image on Sep. 11 and on Sep. 12 we obtained upper limit. The photometry of the combined images are following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-11 18:39:41 1.38753 R 16*300 21.87 0.10 2015-09-12 19:03:44 2.39553 R 21*300 >22.3 (3 sigma) The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)
GCN 18320 table
GRB_name GRB150910A
GCN_number 18320
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18320 SUBJECT: GRB 150910A: Mt. Terskol observatory optical observations DATE: 15/09/16 11:45:10 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Sergeev (Terskol Branch of INASAN), M. Andreev (Terskol Branch of INASAN), E. Mazaeva (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with Zeiss-2000 telescope of Mt. Terskol observatory in R-filter starting on Sep. 11 (UT) 00:40:58. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly detected in a each image. The photometry of a combined image is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-11 00:40:58 0.67083 R 13*120 20.90 0.07 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)
GCN 18327 table
GRB_name GRB150910A
GCN_number 18327
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18327 SUBJECT: GRB 150910A: AAO optical observations DATE: 15/09/17 07:27:12 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), O. Kvaratskhelia(AAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150910A (Pagani et al., GCN 18264) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Sep. 11 (UT) 20:32:45. We obtained several unfiltered images. The afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is clearly visible in a combined image. The photometry of the combined image is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2015-09-11 20:32:45 1.46327 none 49*120 21.55 +/- 0.08 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.), R magnitude deduced from Lupton's transformations.
GCN 18556 table
GRB_name GRB150910A
GCN_number 18556
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 18556 SUBJECT: GRB 150910A: CrAO optical observations DATE: 15/11/03 19:13:53 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), E. Mazaeva (IKI), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150910A (Pagani et al., GCN 18264) with ZTSh telescope of CrAO observatory on Sep. 11 and Sep. 12. We took several images in R,B-filters of 120 s exposure under good weather conditions on Sep. 11 and non-optimal weather conditions (mean seeing of 4") on Sep. 12. The photometry of the afterglow (Pagani et al., GCN 18264; Zheng & Filippenko, GCN 18265) is following Date UT start, t-t0 Filter Exp. OT OT_err UL(3sigma) (mid, days) (s) 2015-09-11 17:56:37 1.3762 R 10*120 21.69 0.12 22.9 2015-09-11 18:18:31 1.4022 B 20*120 22.48 0.15 23.5 2015-09-11 18:39:47 1.4244 R 10*120 21.82 0.10 23.2 2015-09-11 19:22:17 1.4436 B 16*120 22.09 0.10 23.5 2015-09-12 18:04:32 2.3801 R 10*120 n/d n/a 22.3 The photometry is based on SDSS stars used in GCN 18281 (Mazaeva et al.)