//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24888 SUBJECT: GRB 190627A: Swift detection of a burst DATE: 19/06/27 11:48:34 GMT FROM: Scott Barthelmy at NASA/GSFC E. Sonbas (Adiyaman Univ.), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), J.D. Gropp (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:18:31 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190627A (trigger=911609). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 244.830, -5.292, which is RA(J2000) = 16h 19m 19s Dec(J2000) = -05d 17' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple of peaks with a total duration of about 10 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 11:20:20.8 UT, 109.8 seconds after the BAT trigger. The initial XRT centroid was caused by a cosmic ray, and is therefore unrelated to the trigger. While no significant X-ray source was then detected in 20 s of promptly-downlinked data, there is a small number of X-ray photons at the same location as the tentative UVOT source. UVOT took a finding chart exposure of 29 seconds with the White filter starting 114 seconds after the BAT trigger. The 2.7'x2.7' sub-image is unavailable at this time. The list of sources generated on board shows a possible new source at a location of: RA(J2000) = 16:19:18.80 = 244.8283 DEC(J2000) = -05:17:23.2 = -5.2898 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 0.18. Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24889 SUBJECT: GRB 190627A: Swift/UVOT Detection DATE: 19/06/27 15:57:34 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and E. Sonbas (Adiyaman Univ.) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 190627A 115 s after the BAT trigger (Sonbas et al., GCN Circ. 24888). An uncatalogued source consistent with the BAT position is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 16:19:18.69 = 244.82788 (deg.) Dec (J2000) = -05:17:20.8 = -5.28912 (deg.) with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence). 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 115 144 29 18.15 +/- 0.10 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.18 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24890 SUBJECT: GRB 190627A: Enhanced Swift-XRT position DATE: 19/06/27 18:11:26 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 2515 s of XRT Photon Counting mode data and 6 UVOT images for GRB 190627A, 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 = 244.82800, -5.28899 which is equivalent to: RA (J2000): 16h 19m 18.72s Dec (J2000): -05d 17' 20.4" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24892 SUBJECT: GRB 190627A: NUTTelA-TAO optical observations DATE: 19/06/27 20:42:40 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), M. Krugov (AFIF), P. Мinaev (IKI), I. Reva (AFIF), B. Grossan (ECL), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed the field of the GRB 190627A (Sonbas al., GCN 24888) with CDK700 telescope (NUTTelA-TAO project) of Assy-Turgen observatory starting on June 27 (UT) 17:01:00 in R-filter. We clearly detect the optical afterglow (Sonbas al., GCN 24888; Siegel al., GCN 24889). Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. (mid, days) (s) 2019-06-27 17:19:20 0.25056 R 60 17.44 0.05 2019-06-27 19:10:35 0.32782 R 60 17.73 0.07 The photometry is based on the nearby USNO-B1 (R2) stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24893 SUBJECT: GRB 190627A: Montarrenti Observatory optical detection DATE: 19/06/27 23:30:48 GMT FROM: Simone Leonini at Monarrenti Obs S. Leonini, M. Conti and P. Rosi (Montarrenti Observatory, Siena, Italy) report: We observed the optical afterglow of GRB 190627A (Swift trigger 911609, E. Sonbas et al., GCN Circ. 24888) with the automatic 0.53m RC telescope + U47 detector at Montarrenti Observatory (Siena, Italy, IAU code C88). The observations were started immediately after the sunset (approximately 9 hours post-burst) stacking 3 unfiltered CCD exposures of 30s for each run. The OT was detected in all frames as follows: 2019 Jun 27.85897 UT (20:36:55 mid-time) R=18.0 +/-0.14 2019 Jun 27.92990 UT (22:19:03 mid-time) R=18.1 +/-0.13 Preliminary magnitudes were obtained using Astrometrica software using USNO-B1 catalogue for positions and photometry. An ensemble between 121 and 126 stars were used for the magnitude comparison. Measures are not corrected for galactic dust extinction. The position of the GRB (within the error box given by Swift) is the following: RA (J2000.0) 16h 19m 18.70s +/-0.19 Decl. (J2000.0) -05° 17' 20.8" +/-0.18 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24894 SUBJECT: GRB190627A: VIRT Afterglow observation DATE: 19/06/28 03:28:52 GMT FROM: Antonino Cucchiara at UVI D. Morris, S. Prentice, A. Cucchiara, (UVI), P. Gokool daas (SFSU), N. Orange (Orangewave Inc.) report: On June 28.02 UT we began observing the field of GRB 190627A (Sombas et al, GCN 24888; Siegel et al, GCN 24889) with the 0.5m Virgin Island Robotic Telescope (VIRT) located at the Etelman Observatory. We performed a series of exposures in the R filter under optimal weather conditions. In a total coadded exposure of 510s we clearly identify the optical afterglow reported by Siegel et al, (GCN 24889) and Pozanenko et al. (GCN 24892). Our preliminary photometry, calibrated against 10 USNO-B1 stars are: R= 18.38 +- 0.12 This magnitude has not been corrected for Galactic extinction. The VIRT is still in its commissioning phase and further observations are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24895 SUBJECT: GRB 190627A: MASTER optical counterpart observation DATE: 19/06/28 09:04:55 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, F.Balakin, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov,D.Zimnukhov, V.Senik, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias) D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of Swift GRB 190627A error-box (Sonbas et al. GCN 24888, trigger 911609, 11:18:31UT, BAT 16h 19m 19.20s , - 5d 17m 31.20s, R=0.05) 19594 sec after trigger time at 2019-06-27 16:45:05 UT, with upper limit up to 19.4 mag. MASTER auto-detection system detected optical counterpart with unfiltered m_OT~18.2 (W=0.2B+0.8R calibrated by USNO-B1 R2,B2) (OT was discovered by Swift GCN 24888, and also publishied in GCN 24889, GCN 24892, GCN 24893, GCN24894) Observations started at twilight after sunset. Observations began at alt. = 30 deg., the sun altitude was -12.8 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24896 SUBJECT: GRB 190627A: GMG observation DATE: 19/06/28 10:45:28 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, C.-J. Wang and J.-M. Bai report: We observed the field of GRB 190627A (Sonbas et al. GCN Circ. 24888) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 13:49:34, 27, June, 2019, about 2.5 hours after the trigger. We clearly detected the afterglow (Sonbas et al. GCN Circ. 24888; Siegel et al. GCN Circ 24889). We obtained the preliminary magnitude of R~16.9. We compared our result to those from other reports (e.g., Pozanenko et al. GCN Circ 24892, Leonini et al. GCN Circ 24893, Morris et al. GCN Circ. 24894, and Lipunov et al. GCN Circ. 24895). It seems that there was a brightening phase during about 3 hours after the trigger. We encourage other groups for the further investigation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24899 SUBJECT: GRB 190627A: Swift-BAT refined analysis (short-soft burst) DATE: 19/06/28 15:01:57 GMT FROM: Hans Krimm at NSF/NASA-GSFC S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), E. Sonbas (Adiyaman Univ.), 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 downlink, we report further analysis of BAT GRB 190627A (trigger #911609) (Sonbas, et al., GCN Circ. 24888). The BAT ground-calculated position is RA, Dec = 244.843, -5.302 deg which is RA(J2000) = 16h 19m 22.3s Dec(J2000) = -05d 18' 08.6" with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 73%. The mask-weighted light curve shows a single peak, visible only in the softest energy channels, with a duration of about four seconds. The burst location went out of the BAT field soon after T+400 sec due to a spacecraft slew. T90 (15-350 keV) is 1.60 +- 0.28 sec (estimated error including systematics). The time-averaged spectrum from T+0.04 to T+1.78 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.38 +- 0.38. The fluence in the 15-150 keV band is 9.9 +- 2.2 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T+0.78 sec in the 15-150 keV band is 1.1 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Although GRB 190627A has a brief duration, it is not clear that it is a short GRB. The duration and relative softness of the spectrum place it intermediate between most short and long bursts detected by BAT. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/911609/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24900 SUBJECT: GRB 190627A: NUTTelA-TAO optical counterpart observations DATE: 19/06/28 17:31:25 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), A. Volnova (IKI), M. Krugov (AFIF), I. Reva (AFIF), P. Minaev (IKI), B. Grossan (ECL), E. Mazaeva (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed the the optical afterglow (e.g. Sonbas al., GCN 24888; Siegel al., GCN 24889) with CDK700 telescope (NUTTelA-TAO project) of Assy-Turgen observatory starting on June 28 (UT) 15:30:37 in R-filter. We clearly detect the optical afterglow (Sonbas al., GCN 24888; Siegel al., GCN 24889). Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. (mid, days) (s) 2019-06-28 15:30:37 1.18332 R 20*60 19.6 0.16 The photometry is based on the nearby USNO-B1 (R2) stars. We encourage spectroscopic observations to determine redshift and nature of the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24901 SUBJECT: GRB 190627A: Optical imaging and spectroscopy from Calar Alto DATE: 19/06/28 18:44:11 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo, M. Blazek, C. C. Thoene (all HETH/IAA-CSIC), A. Guijarro, and S. Pedraz (both CAHA) report: We observed the afterglow of the short-soft GRB 190627A (Sonbas et al. GCN 24888, Siegel et al. GCN 24889, Evans et al. GCN 24890, Pozanenko et al. GCN 24892, Leonini et al. GCN 24893, Morris et al. GCN 24894, Lipunov et al. GCN 24895, Mao et al. GCN 24896, Barthelmy et al. GCN 24899) with CAFOS at the 2.2 m telescope of the Calar Alto Observatory, in Almeria (Spain). We obtained imaging in g', r', i' and z' bands, as well as a low resolution spectrum. Observations were obtained in inclement weather conditions (2".5 seeing and low transparency because of Calima). The imaging consisted of 5 x 60 s exposures each in the z' and i' bands, and 1 x 300 s each in r' and g' band. The optical counterpart is well detected in each of the individual images. At a mean epoch 21:54:42 UT (10.603 hr after the burst,) the object had a magnitude of r'(AB) = 18.33 +/- 0.04 mag as compared to field stars from the PanSTARRS catalog. The spectrum was obtained at a mean time of 11.675 hrs after trigger and consisted of an exposure of 3 x 1800 s. We used the B-200 grism that covers the range between 3500 and 8800 AA with a resolving power of R ~ 400. The spectrum shows a clear continuum across the complete range, with an average signal-to-noise ratio per dispersion element of 5.5. However, we are not able to match any of the marginal absorption features with a particular redshift. We have made the reduced spectrum publicly available through GRBSpec [1]. Further observations are planned. [1] http://GRBSpec.iaa.es //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24902 SUBJECT: GRB 190627A: NIR imaging from Liverpool Telescope DATE: 19/06/28 18:46:13 GMT FROM: Alexander Kann at IAA-CSIC M. Blazek, L. Izzo, D. A. Kann (all HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), and C. C. Thoene (HETH/IAA-CSIC) report: We observed the afterglow of the short-soft GRB 190627A (Sonbas et al. GCN 24888, Siegel et al. GCN 24889, Evans et al. GCN 24890, Pozanenko et al. GCN 24892, Leonini et al. GCN 24893, Morris et al. GCN 24894, Lipunov et al. GCN 24895, Mao et al. GCN 24896, Barthelmy et al. GCN 24899, Kann et al., GCN 24901) with IO-I on the 2 m Liverpool Telescope, at the Roque de los Muchachos Observatory, in La Palma (Spain). The observation consisted of 4 visits of 10 x 60 s in the H band, with good detections at all epochs. In the first epoch, obtained at a mean epoch 11.6492 hr after the burst, the object is detected at a magnitude of H(AB) = 17.04 +/- 0.10 mag. The photometry was performed with respect to 2MASS field stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24903 SUBJECT: GRB 190627A: Optical imaging by D50 from Ondrejov DATE: 19/06/28 21:19:49 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ) report: We observed GRB 190627A (Sonbas et al. GCNC 24888) with the 50 cm robotic telescope (D50) of Ondrejov observatory in the Czech Republic, obtaining a series of 120s images starting at 20:35UT, i.e. 33.3h post trigger. We can detect the optical afterglow (Siegel & Sonbas, GCNC 24889; Leonini et al., GCNC 24893 and others), providing the preliminary magnitude R=19.8, in a good agreement with extrapolation of the power-law decay slope we observed the last night. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24904 SUBJECT: GRB 190627A: NOT optical observations DATE: 19/06/28 22:08:37 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst Daniele B. Malesani (DTU Space), Jyri J. Lehtinen (MPS), Teemu Willamo (Univ. Helsinki), Zipei Zhu (NAO/CAS), Dong Xu (NAO/CAS), report on behalf of a larger collaboration: We observed the bright optical counterpart (Siegel & Sonbas, GCN 24889) of GRB 190627A (Sonbas et al., GCN 24888) using the Nordic Optical Telescope (NOT) equipped with the StanCam imager, using the Bessel R and I filters. Observations were conducted starting on Jun 28.886 UT (1.415 days after the trigger). The optical counterpart is clearly detected in our images in both filters. We measure a preliminary magnitude r = 20.2 +- 0.1 AB (calibrated against the Pan-STARRS catalog). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24905 SUBJECT: GRB 190627A: GMG observation at the second epoch DATE: 19/06/29 07:55:06 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, C.-J. Wang and J.-M. Bai report: We observed the field of GRB 190627A (Sonbas et al. GCN Circ. 24888) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. We performed the second epoch observation at UT 17:40:32, 28, June, 2019, about 1.3 days after the trigger. We obtained the preliminary magnitude of R~20.0. Our result seems to be consistent to those from other photometric observations at the same epoch (e.g., Pozanenko et al. GCN Circ 24900; Jelinek & Strobl GCN Circ 24903; Malesani et al. GCN Circ 24904). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24906 SUBJECT: GRB 190627A: Swift-XRT refined Analysis DATE: 19/06/29 13:55:34 GMT FROM: Phil Evans at U of Leicester P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , J.A. Kennea (PSU), B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and E. Sonbas (Adiyaman Univ.) report on behalf of the Swift-XRT team: We have analysed 10 ks of XRT data for GRB 190627A (Sonbas et al. GCN Circ. 24888), from 121 s to 119.5 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 24890). The light curve can be modelled with an initial power-law decay with an index of alpha=0.12 (+0.15, -0.19), followed by a break at T+22.1 ks to an alpha of 1.48 (+0.17, -0.16). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.96 (+0.16, -0.09). The best-fitting absorption column is consistent with the Galactic value of 1.8 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 3.6 x 10^-11 (4.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.8 (+/-0.5) x 10^21 cm^-2 Galactic foreground: 1.8 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.96 (+0.16, -0.09) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00911609. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24907 SUBJECT: GRB 190627A : Xinglong 2.16m optical observation DATE: 19/06/29 16:06:41 GMT FROM: Liping Xin at NAOC, SVOM L. P. Xin, J. J. Ren, X. H, Han, G. W. Li, R. S. Zhang, J. Wang, J. Y. Wei, Y. G. Yang, E. W. Liang, X. G. Wang, H. L. Li, X. M. Lu, L. Huang, H. B. Cai, Y. L. Qiu, Y. Xu, Y. J. Xiao, Y. T. Zheng, C. Wu, J. S. Deng, D. W. Xu, D. Turpin, W. L. Dong, P. P. Zhang report: We observed GRB 190627A (Sonbas et al., GCN 24888 ) using the Xinglong-2.16m equipped with the BFOSC camera. Observations were carried out from 13:46:06 to 14:06:29 UT on 2019-06-29, 5*300sec R band images were obtained. The optical afterglow (Siegel & Sonbas, GCN 24889, Lipunov et al., GCN Circ 24895; Morris et al., GCN Circ 24894; Leonini et al., GCN Circ 24893; Pozaneko et al., GCN Circ 24892; Pozanenko et al. GCN Circ 24900; Kann et al., GCN Circ 24901; Blazek et al., GCN Circ 24902; Jelinek & Strobl GCN Circ 24903; Malesani et al. GCN Circ 24904, Mao et al., GCN Circ 24896, 24905) was marginal detected in our stacked image with a magnitude of R=20.5+/-0.2 mag at the mid time of about 2.1 days after the burst. The photometry is calibrated with nearby USNO B1.0 stars //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24911 SUBJECT: GRB 190627A: Koshka Zeiss-1000 optical counterpart observations DATE: 19/06/30 03:16:01 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Novichonok (KIAM), S. Belkin (IKI), A. Zhornichenko (KIAM), A. Pozanenko (IKI), E. Mazaeva (IKI), I. Molotov (KIAM) report on behalf of larger GRB IKI FuN collaboration: We observed the the optical afterglow of GRB 190627A (e.g. Sonbas al., GCN 24888; Siegel al., GCN 24889) with Zeiss-1000 1-m telescope of Koshka Observatory on June, 27 and June, 28 in R-filter. We clearly detect the afterglow in both epoch. Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2019-06-27 18:53:57 0.31732 R 180 17.70 0.08 19.9 2019-06-27 19:42:20 0.35092 R 180 17.80 0.07 20.3 2019-06-28 19:22:50 1.36775 R 5400 19.75 0.08 21.5 The photometry is based on the same USNO-B1.0 (R2) stars used in GCNs 24892 and 24900. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24916 SUBJECT: GRB 190627A: VLT/FORS2 spectroscopic redshift DATE: 19/06/30 10:01:00 GMT FROM: Jure Japelj at API,U of Amsterdam J. Japelj (Uni. Amsterdam), D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo (HETH/IAA-CSIC), J. P. U. Fynbo (DAWN/NBI and DAWN/DTU), D. B. Malesani (DTU Space), V. D'Elia (SSDC), N. R. Tanvir (Univ. Leicester), S. D. Vergani (CNRS -GEPI/Observatorie de Paris), G. Pugliese, L. Kaper (Uni. Amsterdam) report on behalf of the Stargate collaboration: We observed the optical counterpart (Siegel et al., GCN 24889; Pozanenko et al., GCN 24892) of GRB 190627A (Sonbas et al., GCN 24888) with the ESO VLT UT1 equipped with the FORS2 spectrograph. We obtained a 30 min spectrum with the 600RI (512 - 845 nm) and a 30 min spectrum with the 600z (737-1070 nm) grism. Observations started at 01:12:41 UT on June 30 (i.e., 2.57 days after the GRB detection). In the spectrum, the continuum is clearly detected. We detect three MgII absorption systems at redshifts z = 1.942, 1.774 and 1.681. The redshift z = 1.942 and 1.681 absorption systems also exhibit FeII lines. We conclude that z = 1.942 is the likely redshift of GRB 190627A. We acknowledge the ESO observing staff at Paranal, especially Karleyne Silva and Juan Carlos Munoz. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24986 SUBJECT: GRB 190627A: Discovery Channel Telescope late time observations DATE: 19/07/05 16:02:47 GMT FROM: Simone Dichiara at UMCP/NASA/GSFC S.Dichiara (UMD, NASA-GSFC), P. Gatkine (UMD), J.M. Durbak (UMD), E. Troja (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), A. Kutyrev (UMD, NASA-GSFC), S. Veilleux (UMD), report on behalf of a larger collaboration: We observed at the optical counterpart of GRB 190106A (Sonbas et al., GCN 24888) using the Large Monolithic Imager (LMI) on the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ. Observations started on July 05, 07:46:14 UT (about 7.85 days after the Swift trigger) with SDSS r and i filters. We detected the optical counterpart (Siegel & Sonbas, GCN 24889) measuring the following AB magnitudes: Start Time Exposure Filter Magnitude (days from trigger) (s) ------------------------------------------------------- 7.85 4x300 r' 23.36 +- 0.11 7.87 4x300 i' 23.17 +- 0.11 ------------------------------------------------------- Magnitudes are calibrated against Pan-STARRS catalog. We thank the staff of the Discovery Channel Telescope in particular Casey Kyte, Ishara Nisley for assistance with these observations.