GRB 090726
GCN Circular 10028
Subject
GRB 090726 R band observations
Date
2009-10-16T21:08:29Z (16 years ago)
From
Janos Kelemen at Konkoly Obs/Hungary <kelemen@konkoly.hu>
J. Kelemen (kelemen at konkoly.hu) on behalf of the GRB OT observing program
at the Konkoly Observatory.
We present photometry of the source reported by Moskvitin, Fatkhullin and
Valeev (GCN 9709) which was found on a previous survey images made for
asteroid astrometry. The object was observed from the Mountain Station of the
Konkoly Observatory with a 60/90 cm Schmidt telescope using R filter and a
CCD. The exposures were of 300 s. The table contains the time since the Swift
GRB detection to the middle of exposure in seconds, R magnitude and formal
1-sigma magnitude error estimate. Comparison stars were from the USNO A2.0
catalogue. Aperture photometry results obtained using the ASTROMETRICA
astrometry and photometry package.
Time Mag Error. Flag.
[s] [R] [1-sigma]
-------------------------------------
2010 18.21 0.05
2730 18.32 0.05
4530 18.82 0.05
78330 20.60 0.2 Upper Limit
-------------------------------------
This message can be cited.
GCN Circular 9926
Subject
GRB 090726: Skynet/GORT Observations
Date
2009-09-19T20:44:14Z (16 years ago)
From
Josh Haislip at U.North Carolina <haislip@physics.unc.edu>
J. Haislip, D. Reichart, L. Cominsky, K. McLin, T. Graves, G. Spear, K.
Ivarsen, A. LaCluyze, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova,
A. Trotter, J. A. Crain, and M. Nysewander report:
Skynet observed the Skynet/BAT localization of GRB 090726 (Page et al., GCN
9706) with the 14" GORT telescope at Hume Observatory in California
beginning 5.9 hours after the the trigger in I.
We do not detect the afterglow (Page et al., GCN 9707; Moskvitin,
Fatkhullin & Valeev, GCN 9709). Stacking only images that increase the
limiting magnitude yields:
mean 1-sig. 1-sig.
time 3-sig. sys. stat.
since lim. cal. cal. cal.
trig. tel. exp. fil. mag. stars unc. unc.
(h) (# x s) (mag) (mag)
6.2 GORT 15 x 80 I 19.8 84 USNO B1 0.213 0.002
6.8 GORT 8 x 80 R 20.2 178 USNO B1 0.235 0.001
GCN Circular 9741
Subject
GRB 090726: optical observation
Date
2009-07-31T20:36:03Z (16 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (SAI MSU), E. Pavlenko, A. Sklyanov, O. Antoniuk (CrAO), A.
Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 090726 (Page et al., GCN 9706) in
R-filter on Jul. 27 between (UT) 18:19:22 - 20:28:58 with Shajn telescope
of CrAO. We detect afterglow (Moskvitin et al., GCN 9709) in a stacked
image. The photometry against nearby USNO-B1.0 stars is following:
T0+ Filter, Exposure, mag., err.
(d) (s)
0.8626 R 114x60 23.60 +/- 0.25
While the index of power law approximation of the light curve during early
observation (Moskvitin et al., GCN 9709) is ~ -1.0, the power law index
between observation presented by Moskvitin et al. (GCN 9709) and our
observation is -1.6, clearly suggesting a break between 0.079 and 0.863
days.
GCN Circular 9732
Subject
GRB 090726: GRT Optical Observation
Date
2009-07-29T10:22:47Z (16 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC),
T. Okajima (JHU/GSFC), T.N. Ukwatta (GWU/GSFC), Y. Urata (NCU),
C.A. Wallace (FGCU)
We observed the field of GRB 090726 detected by Swift
(trigger #358422; Page et al., GCN Circ. 9706) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).
89 set of 30 sec exposures were taken in the R filter starting
from July 27 02:31:44 (UT) about 3.75 hours after the trigger and
stopped on July 27 03:22:10 (UT). We do not detect the optical
afterglow (Moskvitin et al., GCN Circ. 9709; Fatkhullin et al.,
GCN Circ. 9712; Polasek et al., GCN Circ. 9714; Maticic et al.,
GCN Circ. 9715; Landsman et al., GCN Circ. 9717) both in the
individual images and the combined image. The estimated three
sigma upper limit of the combined image (total exposure of 2670.0 sec)
is ~18.9 mag using the USNO-B1 catalog.
GCN Circular 9717
Subject
GRB090726: Swift/UVOT observations
Date
2009-07-27T16:01:04Z (16 years ago)
From
Wayne Landsman at GSFC/SSAI <wayne.b.landsman@nasa.gov>
W.B. Landsman (NASA/GSFC) and K.Page (U. Leicester)report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090726,
3610s after the BAT trigger (Page et al., GCN Circ. 9706), and the
afterglow first reported by Moskvitin et al., (GCN Circ. 9709) is
detected in the UVOT white, v, and b filters.
The initial magnitudes and upper limits are as follows:
Filter T_start(s) Exp(s) Mag
white 3610 147 20.62 � 0.18
white 4179 197 21.36 � 0.29
v 4589 197 19.98 � 0.36
b 3974 197 20.80 � 0.44
u 3769 197 >20.9 (3 sigma)
uvw1 5000 197 >20.6 (3 sigma)
uvm2 4794 197 >20.6 (3 sigma)
uvw2 4385 197 >21.0 (3 sigma)
The nondetections in the u and UV filters are consistent with the
redshift of z= 2.71 reported by Fatkhullin et al (GCN 9712)
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.045 in the direction of the burst.
The photometry is on the UVOT photometric system described in Poole et
al. (2008, MNRAS, 383, 627).
GCN Circular 9716
Subject
GRB 090726, Swift-BAT refined analysis
Date
2009-07-27T15:57:17Z (16 years ago)
From
Tilan Ukwatta at GSFC/GWU <tilan.ukwatta@gmail.com>
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC),
C. B. Markwardt (GSFC/UMD), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU)
(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 090726 (trigger #358422) (Page, et al.,
GCN Circ. 9706). The BAT ground-calculated position is
RA, Dec = 248.681, 72.866 deg which is
RA(J2000) = 16h 34m 43.5s
Dec(J2000) = +72d 51' 56.5"
with an uncertainty of 1.7 arcmin, (radius, sys+stat,
90% containment). The partial coding was 85%.
The mask-weighted light curve shows a weak single peak
starting at ~T-40 sec, peaking at ~T+5 aec,
and ending at ~T+70 sec. T90 (15-350 keV) is
67.0 +/- 15.2 sec (estimated error including systematics).
The time-averaged spectrum from T-34.7 to T+47.3 sec is
best fit by a simple power-law model. The power law
index of the time-averaged spectrum is 2.25 +/- 0.19.
The fluence in the 15-150 keV band is
8.6 +/- 1.0 x 10^-07 erg/cm2. The 1-sec peak photon
flux measured from T+7.30 sec in the 15-150 keV band
is 0.7 +- 0.2 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/358422/BA/
GCN Circular 9715
Subject
GRB 090726: Afterglow candidate photometryfrom Crni Vrh
Date
2009-07-27T15:43:32Z (16 years ago)
From
Jure Skvarc at OCV <jure@ing.iac.es>
S. Maticic and J. Skvarc on behalf of PIKA observing program at Crni Vrh
Observatory.
We present photometry of the source reported by Moskvitin, Fatkhullin
and Valeev (GCN 9709). The object was observed from Crni Vrh
Observatory with a 60 cm telescope using R filter and a CCD. First
exposure started at 2009-07-26 22:44:31 UT. All twenty exposures were
of 60 s. The table contains the time since the Swift GRB detection to
the middle of exposure in seconds, R magnitude and formal 1-sigma
magnitude error estimate. Comparison stars were 1629-0117020,
1628-0121875 and 1628-0121948 using R2 magnitudes from the USNO B1.0
catalogue.
Time Mag Err.
[s] [R] [1-sigma]
----------------------------------
153.8 18.44 0.04
224.9 18.35 0.04
296.0 17.86 0.04
367.2 17.69 0.04
438.0 17.68 0.04
508.8 17.75 0.04
579.6 17.82 0.04
650.3 17.76 0.04
721.0 17.76 0.04
791.8 17.83 0.04
862.5 17.71 0.04
933.3 17.83 0.04
1004.0 17.89 0.04
1074.7 18.05 0.04
1146.1 18.17 0.04
1218.2 18.11 0.04
1288.9 18.00 0.04
1359.6 18.02 0.04
1430.5 18.16 0.04
1501.5 17.96 0.04
This message can be cited.
GCN Circular 9714
Subject
GRB 090726: D50 optical observations
Date
2009-07-27T14:27:51Z (16 years ago)
From
Martin Jelinek at Inst.Astrophys.Andalucia,Granada <mates@asu.cas.cz>
Cyril Polasek (1), Jan Strobl (1), Martin Jelinek (2), Petr
Kubanek (3), Matus Kocka (1), Martin Nekola (1), Martin Blazek
(1) and Rene Hudec (1) (1. ASU Ondrejov, 2. IAA Granada, 3.
GACE Valencia)
We observed the localization of the Swift GRB090726 (Page et
al., GCN 9706) with the 50 cm telescope in Ondrejov (Czech
Republic), starting at 22:45:41 UT, i.e. 194s after the GRB
trigger.
We clearly detect the afterglow reported by Moskvitin et al.
(GCN 9709) in its rising phase on the first image with
magnitude ~ 18.3 (same calibration as GCN 9709).
This message can be cited.
GCN Circular 9712
Subject
GRB090726: 6-meter telescope redshift
Date
2009-07-27T14:06:50Z (16 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
T. Fatkhullin (SAO RAS, Russia), J. Gorosabel (IAA-CSIC, Spain),
A. de Ugarte Postigo (OAB-INAF, Italy), A. Moskvitin, A. Valeev,
S. Fabrika, O. Sholukhova (SAO RAS, Russia), A. Castro-Tirado
(IAA-CSIC, Spain) & V. Sokolov (SAO RAS, Russia) on behalf of a
larger colaboration, report:
Following the detection of the GRB090726 optical
transient (Moskvitin et al., GCN 9709) we observed
the afterglow with the SAO RAS 6-m telescope in
Caucasus using SCORPIO in the spectroscopic mode.
The wavelength coverage and resolution were
3700-7800AA and FWHM=10A, respectively.
One 10-min long exposure was obtained starting at
00:15 27 July 2009 UT (T-T0 = 1.545 hours after the
trigger). A number of absoption lines were detected
in the spectrum. These are SiI 1526.7, CIV 1548.2,1550.8,
AlII 1670.8, SiII 1304.4,1309.3, SiIV 1393.7,1402.7,
FeII 1608.4 as well as Ly alpha at common z = 2.71
which we interpret as the GRB090726 redshift.
This message may be cited.
P.S. We made a typo in GCN 9709.
In the first line one should read "GRB090726"
instead of "GRB090618". We apologize for our carelessness.
GCN Circular 9711
Subject
GRB 090726: Swift-XRT Team refined analysis
Date
2009-07-27T13:30:11Z (16 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:
We have analysed the first five orbits of data collected for GRB 090726,
comprising 9.4 ks between 3.6 and 28 ks after the trigger, all in Photon
Counting mode. The enhanced XRT position for this burst was given by Evans
et al. in GCN Circ. 9710.
The X-ray light-curve can be modelled with a single power-law with a decay
index of alpha = 1.29 +/- 0.12.
A spectrum formed from these PC data can be fitted with an absorbed
power-law of Gamma = 2.50 +0.26/-0.24 and a total absorbing column of NH =
(1.2 +/- 0.5) x 10^21 cm^-2, which is in excess of the Galactic value
(3.83 x 10^20 cm^-2; Kalberla et al. 2005). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum
is 3.1 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1.
If the light-curve continues to decay with alpha ~ 1.29, the predicted
count rate at 24 hours is 3.4 x 10^-3 count s^-1, corresponding to an
observed (unabsorbed) flux of 1.1 x 10^-13 (1.7 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00358422.
This circular is an official product of the Swift-XRT team.
GCN Circular 9710
Subject
GRB 090726: Enhanced Swift-XRT position
Date
2009-07-27T11:53:24Z (16 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 4286 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 090726, 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 = 248.67985, +72.88426 which is equivalent
to:
RA (J2000): 16h 34m 43.16s
Dec (J2000): +72d 53' 03.4"
with an uncertainty of 1.5 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, arXiv:0812.3662).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 9709
Subject
GRB 090726: optical transient candidate
Date
2009-07-27T03:50:30Z (16 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
A. Moskvitin, T. Fatkhullin & A. Valeev
(SAO-RAS Niznijh Arkhyz, Russia),
on behalf of a larger colaboration, report:
We have observed the field of GRB090618
(Page et al., GCN 9706) with the 1-m telesecope
of the SAO RAS in Caucasus. Within the XRT error
circle (Page et al., GCN 9707) we detected one
object which not present in the DSS. The object's
coordinates are:
R.A. (J2000.0) = 16:34:43.044
DEC. (J2000.0) = +72:53:04.82
with uncertainty about 0.5 arcsec. Using
the USNO A2.0 star 1628-0121951 (R2=14.51)
as a calibration we estimated the object's
brightness as following:
R_mag exp.(sec) mid.time
(sec after the trigger)
18.26 +/- 0.05 60 2126
18.39 +/- 0.05 60 2252
18.33 +/- 0.05 60 2344
18.71 +/- 0.05 120 3183
18.97 +/- 0.05 180 4296
19.17 +/- 0.06 180 5492
19.28 +/- 0.07 240 6089
19.55 +/- 0.12 300 6824
According to its variability we concluded that
the detected object is the OT of the GRB090726.
Further analysis are ongoing.
This message may be cited.
GCN Circular 9708
Subject
GRB 090726: Swift/UVOT Finding Chart Observation
Date
2009-07-27T01:06:32Z (16 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@astro.psu.edu>
M. H. Siegel (PSU), M. A. Stark (PSU) and K.L. Page (U. Leicester)
report
on behalf of the Swift UVOT team:
UVOT observed GRB 090726 (Page et al., GCN Circ 9706) with a finding
chart exposure of 150 seconds with the White filter starting 3610
seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 8'x8' region for the list of
sources generated on-board covers 100% of the XRT error circle reported
by Page et al. (GCN Cic 9707). 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 0.04.
GCN Circular 9707
Subject
GRB 090726: Swift-XRT position of probable counterpart
Date
2009-07-27T00:18:24Z (16 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:
Following a delay caused by an Earth-limb constraint, the Swift-XRT
started observing GRB 090726 about 49 minutes after the trigger, at
23:36:32 UT. The XRT initially centroided on a cosmic ray; however, using
promptly downlinked data we find an uncatalogued X-ray source with an
enhanced position: RA, Dec = 248.6788, 72.8843 (degrees) which is
equivalent to:
RA (J2000.0) = 16 34 42.90
DEC (J2000.0) = +72 53 03.3
with an uncertainty of 2.2 arcsec (radius, 90% containment). This location
is 156.1 arcseconds from the BAT onboard position, inside the BAT error
circle.
It is not possible to determine whether the source is fading at this time.
This circular is an official product of the Swift-XRT team.
GCN Circular 9706
Subject
GRB 090726: Swift detection of a burst
Date
2009-07-26T22:56:51Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
K. L. Page (U Leicester), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), M. M. Chester (PSU),
N. Gehrels (NASA/GSFC), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), M. H. Siegel (PSU), M. A. Stark (PSU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:
At 22:42:27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090726 (trigger=358422). Swift did not slew immediately
to the burst due to an Earth constraint.
The BAT on-board calculated location is
RA, Dec 248.819, +72.871 which is
RA(J2000) = 16h 35m 16s
Dec(J2000) = +72d 52' 15"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a small precursor
at T-20 followed by a single FRED structure overlaid with rapid
variability with a duration of about 50 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~10 sec after the trigger.
Swift will not slew until T0+48.9 minutes. There will be no
XRT or UVOT data until this time.
Burst Advocate for this burst is K. L. Page (kpa 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.)