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This page lists all entries on GRB150728A in GRBweb

Summary IPN Swift GCN 18087 GCN 18088 GCN 18090 GCN 18091 GCN 18092 GCN 18093 GCN 18094 GCN 18096 GCN 18097 GCN 18098 GCN 18115

Summary table
Variable	Value	Source
T0	12:51:11 UTC	GCN_circulars,Swift Det
ra	292.2287°	Swift
decl	33.9160°	Swift
pos_error	5.18e-04°	Swift
T90	0.83 s	Swift
T90_start	12:51:11 UTC	Swift
fluence	3.30e-08 erg/cm²	Swift
T100	0.83 s
GBM_located	False
mjd	57231.53554398148	GCN_circulars,Swift Det

IPN table
GRB_name	GRB150728A
ra	292.2875°
decl	33.9000°
pos_error	5.00e-02°

Swift table
GRB_name	GRB150728A
t_trigger	12:51:11 UTC
ra	292.2287°
decl	33.9160°
pos_error	5.18e-04°
T90	0.83 s
fluence	3.30e-08 erg/cm²

GCN 18087 table
GRB_name	GRB150728A
GCN_number	18087
Detection_method	Swift Det
t_trigger	12:51:11 UTC
ra	292.2880°
decl	33.9040°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18087 SUBJECT: GRB 150728A: Swift detection of a GRB DATE: 15/07/28 13:14:33 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC), A. A. Breeveld (UCL-MSSL), D. N. Burrows (PSU), S. B. Cenko (GSFC), P. A. Evans (U Leicester), C. Gronwall (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), P. Romano (INAF-IASFPA), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 12:51:11 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150728A (trigger=650617). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 292.288, +33.904 which is RA(J2000) = 19h 29m 09s Dec(J2000) = +33d 54' 14" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two weak peaks with a total duration of about 20 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 12:52:21.1 UT, 70.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 292.2269, 33.9165 which is equivalent to: RA(J2000) = 19h 28m 54.46s Dec(J2000) = +33d 54' 59.4" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 188 arcseconds from the BAT onboard position, outside 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 consistent with the Galactic value of 2.59 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 75 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.20. Burst Advocate for this burst is H. A. Krimm (hans.krimm 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 18088 table
GRB_name	GRB150728A
GCN_number	18088
Detection_method	Swift-XRT Det
ra	292.2287°
decl	33.9160°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18088 SUBJECT: GRB 150728A: Enhanced Swift-XRT position DATE: 15/07/28 15:06:58 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 1020 s of XRT Photon Counting mode data and 1 UVOT images for GRB 150728A, 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 = 292.22873, +33.91604 which is equivalent to: RA (J2000): 19h 28m 54.89s Dec (J2000): +33d 54' 57.7" with an uncertainty of 4.0 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 18090 table
GRB_name	GRB150728A
GCN_number	18090
Detection_method	Swift-BAT Det
ra	292.2284°
decl	33.9161°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18090 SUBJECT: GRB 150728A: FTN observations DATE: 15/07/28 17:07:38 GMT FROM: Simone Dichiara at Ferrara U/Italy S. Dichiara, C. Guidorzi (U. Ferrara), C.G. Mundell (U. Bath), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana) on behalf of a large collaboration report: The 2-m Faulkes Telescope North began observing Swift GRB 150728A (Krimm et al. GCN 18087) on July 28, 13:48:25 UT (~57 minutes after the BAT trigger) with SDSS r and i filters. we identify an uncatalogued object within XRT error circle (Beardmore et al. GCN 18088), at the following position: RA(J2000) = 19:28:54.81 Dec(J2000)= +33:54:58.0 with an uncertainty of 1". The counterpart has the following magnitudes: Mid time from Total Exp Filter Magnitude trigger (min) (s) ------------------------------------------------- 61.8 120x5 r' 21.8 +- 0.3 73.3 120x5 i' 20.7 +- 0.3 ------------------------------------------------- Magnitudes are calibrated against nearby USNOB-1 stars (R2 and I). Presently we cannot state anything about possible variability in the source flux. However, we note that field is quite crowded.

GCN 18091 table
GRB_name	GRB150728A
GCN_number	18091
Detection_method	Swift-BAT Det
ra	292.2710°
decl	33.9060°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18091 SUBJECT: GRB 150728A: Swift-BAT refined analysis DATE: 15/07/28 17:30:34 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), 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) (i.e. the Swift-BAT team): Using the data set from T-240 to T+946 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 150728A (trigger #650617) (Krimm, et al., GCN Circ. 18087). The BAT ground-calculated position is RA, Dec = 292.271, 33.906 deg, which is RA(J2000) = 19h 29m 05.1s Dec(J2000) = +33d 54' 20.8" with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single spike starting at ~T_zero and ending at ~T+1.5 sec. T90 (15-350 keV) is 0.83 +- 0.23 sec (estimated error including systematics). The time-averaged spectrum from T+0.24 to T+1.20 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.02 +- 0.48. The fluence in the 15-150 keV band is 3.3 +- 1.0 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T+0.22 sec in the 15-150 keV band is 0.5 +- 0.1 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/650617/BA/

GCN 18092 table
GRB_name	GRB150728A
GCN_number	18092
Detection_method	Swift-UVOT Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18092 SUBJECT: GRB 150728A: Swift/UVOT Upper Limits DATE: 15/07/28 21:08:25 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and H. A. Krimm (CRESST/GSFC/USRA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150728A 75 s after the BAT trigger (Krimm et al., GCN Circ. 18087). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 18088) or the Faulkes position (Dichiara et al. GCN Circ. 18090) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 75 225 147 >21.3 u_FC 288 537 246 >20.4 white 75 6991 730 >22.0 v 617 5982 275 >19.8 b 543 6803 452 >21.1 u 288 6597 678 >21.0 w1 668 6392 452 >20.4 m2 643 6187 452 >20.2 w2 593 5777 255 >20.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.20 in the direction of the burst (Schlegel et al. 1998).

GCN 18093 table
GRB_name	GRB150728A
GCN_number	18093
Detection_method	Swift-XRT Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18093 SUBJECT: GRB 150728A: Swift-XRT refined Analysis DATE: 15/07/29 01:14:03 GMT FROM: Phil Evans at U of Leicester C. Pagani (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and H.A. Krimm report on behalf of the Swift-XRT team: We have analysed 6.7 ks of XRT data for GRB 150728A (Krimm et al. GCN Circ. 18087), from 79 s to 30.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 18088). The source is fading with alpha >0.4. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00650617. This circular is an official product of the Swift-XRT team.

GCN 18094 table
GRB_name	GRB150728A
GCN_number	18094
Detection_method	Optical
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18094 SUBJECT: GRB 150728A: AAO optical observations DATE: 15/07/29 18:30:31 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), R. Inasaridze (AAO), Sh. Makandarashvili (AAO), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150728A (Krimm et al. GCN 18087) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Jul. 28 (UT) 19:32:14. Within the enhanced XRT error circle (Beardmore et al. GCN 18088) we detected the object coinciding with the object found by FTN (Dichiara et al. GCN 18090). A photometry of the object is following Date UT start t-T0 Filter Exp. OT (mid, days) (s) 2015-07-28 19:32:14 0.30491 None 28*120 20.6+/-0.25 The photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 1239-0338943 17.06 1239-0338998 16.69 The photometry could be biased by nearby star. Presently we cannot say nothing about variability of the object and more observation is necessary to confirm/reject the object as afterglow of GRB 150728A.

GCN 18096 table
GRB_name	GRB150728A
GCN_number	18096
Detection_method	Swift-XRT Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18096 SUBJECT: GRB 150728A: RATIR Optical Observations DATE: 15/07/29 20:07:03 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 150728A (Krimm et al., GCN 18087) 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 2015/07 29.19 to 2015/07 29.48 UTC (15.73 to 22.75 hours after the BAT trigger), obtaining a total of 5.29 hours exposure in the r, i, and z bands. The brightest source within the enhanced Swift/XRT error circle (Beardmore et al., GCN 18088) is the cataloged source 2MASS 19285425+3354576, for which we determine a position of 19:28:54.26 +33:54:57.6 (J2000, 0.5") and magnitudes: r 16.71 0.02 i 16.49 0.01 z 16.14 0.04 We detect two other uncataloged sources on the edge of the error circle. For source A we determine a position of 19:28:54.80 +33:54:58.2 (J2000, 0.5") and magnitudes: r 21.37 0.04 i 20.89 0.04 z 19.54 0.13 and for source B we determine 19:28:54.25 +33:55:2.6 (J2000, 0.5") and: r 21.11 0.04 i 20.73 0.03 z 20.21 0.21 These magnitudes are in comparison with the USNO-B1 and 2MASS catalogs, are in the AB system, and are not corrected for Galactic extinction in the direction of the GRB. Our source A appears to correspond to the source reported by Dichiara et al. (GCN 18090). If this association is correct, then there is little evidence for fading between about 1 hour and 16-23 hours. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.

GCN 18097 table
GRB_name	GRB150728A
GCN_number	18097
Detection_method	Optical
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18097 SUBJECT: GRB 150728A: TSHAO optical observations DATE: 15/07/30 18:41:10 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150728A (Krimm et al. GCN 18087) with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory starting on Jul. 29 (UT) 18:34:50. We obtained several images in R-filter. In a combined image we do not detect the FTN object (Dichiara et al. GCN 18090) also visible in AAO observations (Mazaeva et al., GCN 18094) and source A in RATIR observations (Watson et al., GCN 18096). A photometry of the field is following Date UT start t-T0 Filter Exp. ULimit (3sigma) (mid, days) (s) 2015-07-29 18:34:50 1.26425 R 15*300 21.2 The photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 1239-0338943 17.06 1239-0338998 16.69 Also we marginally detect object B of the RATIR observations (Watson et al., GCN 18096) in our current and previous observation of the field (Mazaeva et al., GCN 18094). The finding chart can be found in http://grb.rssi.ru/GRB150728A/GRB150728A_AAO_left_TSHAO_right.png Would the source A be a non-variable point like object with magnitudes of r=21.37+/-0.04 and i=20.89+/-0.04 (Watson et al., GCN 18096) in our observation the object A might be detected as the object with a magnitude less than R=21.3 (3 sigma). So we tentatively suggest the object A as an afterglow candidate.

GCN 18098 table
GRB_name	GRB150728A
GCN_number	18098
Detection_method	Swift-BAT Det
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18098 SUBJECT: GRB 150728A: Continued RATIR Optical Observations DATE: 15/07/31 17:52:51 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 150728A (Krimm et al., GCN 18087) 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 2015/07 31.22 to 2015/07 31.46 UTC (64.53 to 70.24 hours after the BAT trigger), obtaining a total of 3.60 hours exposure in the r, i, and z bands. For source A of Watson et al. (GCN 18096), we determine: r 21.26 0.04 i 20.90 0.04 z 19.43 0.13 For source B of Watson et al. (GCN 18096), we determine: r 20.91 0.04 i 20.70 0.04 z 20.48 0.31 These magnitudes are in comparison with the USNO-B1 and 2MASS catalogs, are in the AB system, and are not corrected for Galactic extinction in the direction of the GRB. Our source A appears to correspond to the source reported by Dichiara et al. (GCN 18090). If this association is correct, then there is little evidence for fading between observations at about 1 hour, 16-23 hours, and 65-70 hours. This is in contrast to the suggestion of Mazaeva et al. (GCN 18097), who suggested that source A might indeed be the fading afterglow on the basis of a 3-sigma non-detection at 30 hours. Similarly, there is little evidence for fading of source B between 16-23 hours and 65-70 hours. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.

GCN 18115 table
GRB_name	GRB150728A
GCN_number	18115
Detection_method	Optical
Circular_text	TITLE: GCN CIRCULAR NUMBER: 18115 SUBJECT: GRB 150728A: TNG optical observations DATE: 15/08/05 20:10:52 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza (INAF/OABr), V. D'Elia (INAF/OAR and ASI/ASDC), V. Lorenzi, H. Stoev (INAF/TNG) report on behalf of the CIBO collaboration: We observed the field of the short GRB 150728A (Krimm et al., GCN 18087; Ukwatta et al. GCN 18091) with the 3.6m TNG telescope equipped with the DOLoRes camera. Observations consisted of 12 images in the r-sdss band for a total of 48 min exposure. The seeing was ~1.2". No object is detected within the enhanced XRT position (Beardmore et al., GCN 18088), down to a limiting magnitude r > 24.5 (calibrated against nearby USNO-B1 stars). The mean time of the observation was 2015 Jul 30.9439 UT (2.41 days after the GRB). In particular, we find no evidence for fading for the object reported by Dichiara et al. in GCN 18090 (which appears to be point-like in our images), by measuring in our dataset a magnitute of r = 21.4 +/- 0.1 for this source (calibrated against nearby USNO-B1 stars).