GRB180111A

This page lists all entries on GRB180111A in GRBweb

Summary IPN Swift GCN 22318 GCN 22319 GCN 22320 GCN 22321 GCN 22322 GCN 22323 GCN 22324 GCN 22327 GCN 22331 GCN 22333 GCN 22336 GCN 22341 GCN 22352

Summary table
Variable Value Source
T0 16:42:06 UTC GCN_circulars,Swift Det
ra 149.7797° Swift
decl 48.2674° Swift
pos_error 1.94e-04° Swift
T90 50.6 s Swift
T90_start 16:42:06 UTC Swift
fluence 1.02e-05 erg/cm² Swift
T100 50.6 s
GBM_located False
mjd 58129.69590277778 GCN_circulars,Swift Det
IPN table
GRB_name GRB180111A
ra 149.8417°
decl 48.2667°
pos_error 5.00e-02°
Swift table
GRB_name GRB180111A
t_trigger 16:42:06 UTC
ra 149.7797°
decl 48.2674°
pos_error 1.94e-04°
T90 50.6 s
fluence 1.02e-05 erg/cm²
GCN 22318 table
GRB_name GRB180111A
GCN_number 22318
Detection_method Swift Det
t_trigger 16:42:06 UTC
ra 149.8410°
decl 48.2650°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22318 SUBJECT: GRB 180111A: Swift detection of a burst with an optical counterpart DATE: 18/01/11 17:12:29 GMT FROM: David Palmer at LANL A. Y. Lien (GSFC/UMBC), A. P. Beardmore (U Leicester), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU), S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU), A. Tohuvavohu (PSU) and T. N. Ukwatta (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 16:42:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180111A (trigger=804692). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 149.841, +48.265 which is RA(J2000) = 09h 59m 22s Dec(J2000) = +48d 15' 53" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 80 sec. The peak count rate was ~11000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 16:43:34.1 UT, 87.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 149.77814, 48.26769 which is equivalent to: RA(J2000) = 09h 59m 06.75s Dec(J2000) = +48d 16' 03.7" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 150 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.08 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.7 (+3.91/-3.29) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 5.71e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 97 seconds after the BAT trigger. An afterglow candidate has been found in the initial data products at RA=9:59:7.0 Dec=+48:16:03.3 which is RA=149.77938, Dec=48.26758 deg (J2000) matching the XRT position. This source lies in the wings of a bright star and we will provide a magnitude after further ground processing. 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 22319 table
GRB_name GRB180111A
GCN_number 22319
Detection_method Swift-XRT Det
ra 149.7798°
decl 48.2677°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22319 SUBJECT: GRB 180111A: Enhanced Swift-XRT position DATE: 18/01/11 20:37:43 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 461 s of XRT Photon Counting mode data and 1 UVOT images for GRB 180111A, 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 = 149.77977, +48.26769 which is equivalent to: RA (J2000): 09h 59m 7.14s Dec (J2000): +48d 16' 03.7" with an uncertainty of 1.8 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 22320 table
GRB_name GRB180111A
GCN_number 22320
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22320 SUBJECT: GRB180111A: Xinglong TNT possible optical detection DATE: 18/01/11 23:20:38 GMT FROM: L.P. Xin at NAOC L. P. Xin, C. Liu, J. Y. Wei, Y. L. Qiu, J. S. Deng, J. Wang, X. H. Han, X. M. Meng and C. Wu report: We began to observe GRB 180111A (Lien et a l., GCN22318) with Xinglong 0.8-m TNT telescope at 2018-01-11, 14:43:34(UT), about 93 sec the burst. We obtained several white and R-band images. In any single white band frame, no any new optical transient was detected within UVOT circle and XRT circle (Lien et a l., GCN22318, Evens et al., GCN 22319) down to 18.5 magnitude at the mid time of 113 sec after the burst . However, there is a marginal source in the 20*20sec coadded image within the XRT circle (Evens et al., GCN 22319), whose position is consistent with the location of the reported optical counterpart (Lien et a l., GCN22318). The brightness is about 20.0+/-0.3 calibrated by the local USNO B1.0 R2 mag at the mid time of 300 sec after the burst. We are making further analysis for the possible low S/N detection since there is a bright star near the GRB location. The message may be cited. [GCN OPS NOTE(11jan18): The latter 'A' was added to the GRB name in the Subject-line.]
GCN 22321 table
GRB_name GRB180111A
GCN_number 22321
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22321 SUBJECT: GRB 180111A: AGILE/MCAL detection DATE: 18/01/12 00:02:25 GMT FROM: Francesco Verrecchia at ASDC F. Verrecchia (SSDC and INAF/OAR), A. Trois (INAF/OA-Cagliari), A.Ursi (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), N. Parmiggiani (INAF/IASF-Bo), C. Pittori (SSDC and INAF/OAR), M. Marisaldi (INAF/IASF-Bo and Bergen University), F. Longo (Univ. Trieste and INFN Trieste), A. Bulgarelli (INAF/IASF-Bo), M. Cardillo (INAF/IAPS), F. Lucarelli (SSDC and INAF/OAR), M. Pilia (INAF/OA-Cagliari), G. Piano (INAF/IAPS), I. Donnarumma (ASI), G. Minervini, A. Argan, Y. Evangelista (INAF/IAPS), V. Fioretti, F. Fuschino (INAF/IASF-Bo), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE Mini-CALorimeter (MCAL) detected at T0 = 2018-01-11 16:42:06.0 +/- 0.02 UTC the long GRB 180111A reported by Swift (Lien et al., GCN 22318), in the acquired data interval (following an internal trigger) started at T1=16:42:05.50 UTC and ended at 16:42:12.40 UTC. The MCAL light curve shows three main peaks starting at T0-0.15 s till ~6 s, with the main part within T0-0.10 s and T0+5.40 s. The main GRB interval released a total number of ~5537 counts at E>400 keV in the detector, above an average background rate of 18 counts/32ms. The AGILE-MCAL detector has a full solid angle acceptance, and is operational in the range 0.4 - 100 MeV.
GCN 22322 table
GRB_name GRB180111A
GCN_number 22322
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22322 SUBJECT: GRB 180111A: Swift-XRT refined Analysis DATE: 18/01/12 01:25:41 GMT FROM: Phil Evans at U of Leicester S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 180111A (Lien et al. GCN Circ. 22318), from 94 s to 23.6 ks after the BAT trigger. The data comprise 117 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 22319). The late-time light curve (from T0+4.0 ks) can be modelled with a power-law decay with a decay index of alpha=1.46 (+0.38, -0.29). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.48 (+/-0.09). The best-fitting absorption column is 4.0 (+3.0, -2.6) x 10^20 cm^-2, in excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.66 (+0.21, -0.12) and a best-fitting absorption column of 1.17 (+4.88, -0.09) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.17 (+4.88, -0.09) x 10^20 cm^-2 Galactic foreground: 1.1 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.66 (+0.21, -0.12) If the light curve continues to decay with a power-law decay index of 1.46, the count rate at T+24 hours will be 9.2 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.5 x 10^-14 (3.6 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/00804692. This circular is an official product of the Swift-XRT team.
GCN 22323 table
GRB_name GRB180111A
GCN_number 22323
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22323 SUBJECT: GRB 180111A: RATIR Optical and NIR Observations DATE: 18/01/12 15:36:30 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report: We observed the field of GRB 180111A (Lien, et al., GCN 22318) 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 2018/01 12.21 to 2018/01 12.56 UTC (12.35 to 20.68 hours after the BAT trigger), obtaining a total of 5.31 hours exposure in the r and i bands and 2.22 hours exposure in the Z and Y bands. We find a source within the Swift-XRT error circle (Evans, et al., 22319). In comparison with the SDSS DR9 and 2MASS catalogs, we measure: r = 20.90 +/- 0.10 i = 20.41 +/- 0.10 Z = 20.61 +/- 0.15 Y = 20.41 +/- 0.15 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We note that there is an r=22.7 mag SDSS source, perhaps the host galaxy, within the XRT error region and at a position consistent with our source position. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.
GCN 22324 table
GRB_name GRB180111A
GCN_number 22324
Detection_method Swift-BAT Det
ra 149.7820°
decl 48.2540°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22324 SUBJECT: GRB 180111A: Swift-BAT refined analysis DATE: 18/01/12 16:04:27 GMT FROM: Amy Lien at GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180111A (trigger #804692) (Lien et al., GCN Circ. 22318). The BAT ground-calculated position is RA, Dec = 149.782, 48.254 deg which is RA(J2000) = 09h 59m 07.7s Dec(J2000) = +48d 15' 14.6" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 70%. The mask-weighted light curve shows several overlapping pulses that starts at ~ T0 and ends at ~ T+70 s. The main peak occurs at ~ T+ 14 s. T90 (15-350 keV) is 50.6 +- 1.9 sec (estimated error including systematics). The time-averaged spectrum from T-0.30 to T+68.59 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.30 +- 0.03. The fluence in the 15-150 keV band is 1.02 +- 0.02 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+13.89 sec in the 15-150 keV band is 4.9 +- 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/804692/BA/
GCN 22327 table
GRB_name GRB180111A
GCN_number 22327
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 22327 SUBJECT: GRB 180111A: Swift/UVOT Detection DATE: 18/01/13 13:53:26 GMT FROM: Jeffrey Gropp at PSU J. D. Gropp (PSU) 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 180111A 98 s after the BAT trigger (Lien et al., GCN Circ. 22318). A fading source consistent with the XRT position (Evans et al. GCN Circ. 22319) is detected in the initial UVOT exposures. Preliminary detections 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 84 233 147 19.95+-0.21 white 86 6202 552 20.37+-0.16 v 64 5181 206 >19.23 b 4365 6002 393 >20.60 u 296 5795 639 20.25+-0.35 w1 5391 5591 196 >19.50 m2 650 670 19 >17.15 w2 4776 6407 393 19.60+-0.27 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN 22331 table
GRB_name GRB180111A
GCN_number 22331
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22331 SUBJECT: GRB 180111A: AbAO optical observations DATE: 18/01/13 19:36:34 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), S. Schmalz (ISON), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), A. Volnova (IKI), I. Molotov (KIAM), report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 180111A (Lien et al., GCN 22318) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Jan., 11 (UT) 23:53:51. We obtained several unfiltered images of the field. Within enhanced XRT error circle (Evans et al., GCN 22319) we detected the afterglow (Lien et al., GCN 22318; Xin et al., 22320; GCN Butler et al., GCN 22323; Gropp et al., GCN 22327). Preliminary photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err UpLim (3 sigma) (mid, days) (s) 2018-01-11 23:53:51 0.3213 CR 62*60 20.7 0.2 22.0 Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes) USNO-B.1_id R2 1382-0239231 15.78 1383-0226386 16.52 1383-0226440 15.90
GCN 22333 table
GRB_name GRB180111A
GCN_number 22333
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 22333 SUBJECT: GRB 180111A CALET Gamma-Ray Burst Monitor detection DATE: 18/01/14 12:55:13 GMT FROM: Takanori Sakamoto at AGU Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 180111A (Lien et al., GCN circ. 22318; Verrecchia et al., GCN circ. 22321) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 16:42:04.15 on 11 January 2018. The burst signal was seen by the all CGBM instruments. The light curve of the SGM shows two overlapping peaks. The emission starts at T+2.1 sec, peaks at T+2.6 sec and ends at T+43.4 sec. The T90 and the T50 durations measured by the SGM data are 34.3 +- 6.6 sec and 11.0 +- 2.4 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1199723921 The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
GCN 22336 table
GRB_name GRB180111A
GCN_number 22336
Detection_method Konus-Wind Det
t_trigger 16:42:10.616 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 22336 SUBJECT: Konus-Wind observation of GRB 180111A DATE: 18/01/15 10:37:21 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The bright long-duration GRB 180111A (Swift-BAT detection: Lien et al., GCN Circ. 22318; AGILE-MCAL detection: Verrecchia et al., GCN Circ. 22321) triggered Konus-Wind at T0=60130.616 s UT (16:42:10.616). The burst light curve shows a multipeaked structure which starts at ~T0-0.2 s and has a total duration of ~61 s. The emission is seen up to ~6 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180111_T60130/ As observed by Konus-Wind, the burst had a fluence of 8.44(-0.57,+0.64)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+0.018 s, of 1.06(-0.21,+0.22)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+39.424 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.94(-0.06,+0.06) and Ep = 894(-95,+113) keV (chi2 = 106/98 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.7 (chi2 = 106/97 dof). The spectrum near the maximum count rate (measured from T0+0.000 to T0+7.424 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: with alpha = -0.51(-0.08,+0.09) and Ep = 895(-82,+94) keV (chi2 = 89/98 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.8 (chi2 = 89/97 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 22341 table
GRB_name GRB180111A
GCN_number 22341
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 22341 SUBJECT: GRB 180111A: Insight-HXMT/HE observation DATE: 18/01/15 12:20:59 GMT FROM: Shaolin Xiong at IHEP G. Li, S. L. Xiong, X. B. Li, C. K. Li, J. Y. Liao, C. Z. Liu, X. F. Li, Z. W. Li, X. F. Lu, Z. Chang, J. L. Zhao, A. M. Zhang, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2018-01-11T16:42:06 (T0), Insight-HXMT/HE detected GRB 180111A (trigger ID: HEB180111695) in a routine search of the data,which is also triggered by Swift/BAT (Lien et al.,GCN 22318),AGILE/MCAL(Verrecchia et al.,GCN 22321),and CALET(Asaoka et al.,GCN 22333). The Insight-HXMT/HE light curve mainly consists of multi-pulses with a duration (T90) of 19.94 s measured from T0+0.185 s. The 500-ms peak rate, measured from T0+0.422 s, is 2332.29 cnts/sec. The total counts from this burst is 13972.02 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB180111695_lc.jpg All measurements above are made with the CsI detectors operating in the GRB mode, in which the energy range is increased to about 200 - 3000 keV (record energy), compared to the normal mode of 80 - 800 keV. Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. The analysis results presented above are preliminary; final results will be published elsewhere. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org/index.php/enhome .
GCN 22352 table
GRB_name GRB180111A
GCN_number 22352
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22352 SUBJECT: GRB 180111A AROMA-N optical observation DATE: 18/01/16 14:15:09 GMT FROM: Takanori Sakamoto at AGU Y. Kitaoka, T. Sakamoto (AGU) We observed the field of GRB 180111A detected by Swift (Lien et al. GCN circ. 22318) with the 0.3 m AROMA-N telescope located at Aoyama Gakuin University (Sagamihara, Japan). 10 images of 60 sec exposures were taken in the R filter starting from January 11 on 16:44:50 (UT) about 3 minutes after the trigger and stopped on 16:56:51 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the location of the optical afterglow (Lien et al. GCN circ. 22318). The estimated five sigma upper limit is ~16.6 mag using the USNO-B1 catalog.