GRB 050712
GCN Circular 3573
Subject
GRB 050712: Swift detection of a weak burst
Date
2005-07-12T15:04:45Z (20 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
D. Grupe (PSU), S. Barthelmy (GSFC), J. Cummings, (GSFC/NRC),
H. Krimm (GSFC/USRA), C. Markwardt, (GSFC/UMD), D. Palmer (LANL),
T. Sakamoto (GSFC), D. Burrows, J. Nousek, A. Falcone, C. Gronwall (PSU),
T. Poole, A. Blustin (MSSL), and N. Gehrels (GSFC) on behalf of the Swift team:
At 14:00:27.51 UT, the Swift Burst Alert Telescope (BAT) triggered and located
on-board GRB050712 (trigger=145581). The spacecraft slewed immediately.
The flight-determined location is RA,Dec 77.693,+64.899 {+05h 10m 46s,+64d
53' 56"} (J2000) with an uncertainty of 3 arcmin (radius, stat+sys). The
burst lightcurve
has 4-5 peaks all within ~35 sec duration. This is a weak burst with a peak
count rate of 500 cnts/sec in the 15-350 keV band.
This burst should not be confused with Trigger=145563 two hours earlier
today.
Based on preliminary analysis, the BAT team believes the earlier trigger is
not
a real GRB.
The XRT attempted to centroid on the afterglow at 14:03:14 UT (166 s after the
BAT trigger) but could not find a bright enough source for a successful
on-board
centroid. Ground analysis will be required to determine whether there is
an X-ray
counterpart.
The Swift Ultra Violet/Optical (UVOT) observations began at 14:03:11.5 UT,
164 seconds after the BAT trigger. The first data taken after the spacecraft
settled was a 100 sec exposure using the V filter with the midpoint of the
observation at 214 sec after the BAT trigger. Based on comparisons to the
DSS, we detect no new source. The 5-sigma upper limit in the V-filter is
17.94 mag.
GCN Circular 3574
Subject
GRB 050712: Swift XRT afterglow position
Date
2005-07-12T15:54:17Z (20 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
A. Falcone, D. N. Burrows, D. C. Morris, D. Grupe, J. L. Racusin, J. A.
Nousek (PSU),
J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS), and N. Gehrels (GSFC) report on
behalf of the Swift XRT team:
The Swift BAT instrument detected GRB 050712 at 14:00:27.51 UT on 12 July
2005 (Grupe et al. 2005, GCN 3573). The observatory executed an automated
slew to the BAT position and the XRT began taking data at 14:03:14 UT
(166.1 s after the BAT trigger). The XRT was in Auto state but the source
was not initially bright enough for a successful on-board centroid. In
ground-processed data we find a bright uncataloged, rapidly fading X-ray
source located at:
RA(J2000) = 05:10:47.9,
Dec(J2000) = +64:54:51.5.
We estimate an uncertainty of about 6 arcseconds radius (90%
containment). This source is located 56 arcseconds from the BAT position
in GCN 3573.
GCN Circular 3575
Subject
GRB050712: UVOT candidate optical counterpart
Date
2005-07-12T19:44:20Z (20 years ago)
From
Evert Rol at U.Leicester <er45@star.le.ac.uk>
E. Rol (U. Leicester), T. Poole, K. McGowan (MSSL), D. Grupe,
J. Nousek (PSU), W. Voges (MPE), and N. Gehrels (GSFC) report on behalf
of the Swift UVOT team:
Analysis of the quick-look data from the UVOT for GRB050712 (Grupe et
al., GCN 3573) reveals a single, relatively bright source inside the
XRT error circle (Falcone et al., GCN 3574) which is not visible in
the DSS red and blue surveys. Its position is (J2000):
RA 5:10:48.1
Dec 64:54:47.6
with the astrometry calibrated to the 2MASS catalogue.
An initial estimate of the V-band magnitude for the source over the
timespan of 164-264 seconds after the trigger is V = 18.02 +/- 0.29.
Further analysis is underway to investigate the variability of the
source.
We note that the early UVOT findingchart ('genie image') was not
centred at BAT position, which resulted in the candidate XRT/UVOT
position being outside the field of view of the findingchart.
GCN Circular 3576
Subject
GRB 050712: Swift-BAT Refined Analysis
Date
2005-07-12T20:18:09Z (20 years ago)
From
Craig Markwardt at NASA/GSFC/UMD <craigm@milkyway.gsfc.nasa.gov>
C. Markwardt (NASA GSFC/UMD), M. Ajello (MPE), S. Barthelmy,
L. Barbier (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL),
R. Fink, N. Gehrels (GSFC), D. Hullinger (GSFC/UMD),
H. Krimm (GSFC/USRA), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama),
J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Using the full data set from the recent telemetry downlink, further
analysis of Swift-BAT GRB050712 (Trigger #145881; Grupe et al., GCN
Circ 3573) yields a refined position of RA, Dec 77.698, +64.931 {05h
10m 48s, +64d 55' 52"} (J2000) with an uncertainty of 3 arcmin
(radius, 90% confidence, statistical+systematic).
The burst duration (T90) was determined to be 48 +/- 2 seconds (15-350
keV) starting at T-7.8 seconds. The spectrum over the interval from
T-11 to T+44 seconds can be fit with a power law with photon index
1.56 +/- 0.18 and yields a fluence of 1.8 X10^-6 erg/cm^2 in the
15-350 keV band. The peak flux in a 1-sec wide window starting at
T+17.4 seconds is 0.6 +/- 0.2 ph/cm^2/sec. The light curve is a long
smooth "bump" with weak, if any, structure.
GCN Circular 3579
Subject
GRB050712: XRT refined analysis
Date
2005-07-13T03:39:58Z (20 years ago)
From
Dirk Grupe at PSU/Swift-XRT <grupe@astro.psu.edu>
D. Grupe, D. Burrows, D. Morris, A. Falcone, J. Nousek,
P. Meszaros, M. Chester (PSU), N. Gehrels (GSFC),
on behalf of the Swift-XRT team:
Title: GRB050712: XRT refined analysis
We analysed the XRT data of the first four
orbits of GRB050712 (GCN 3573, Grupe et al., 2005).
The refined position using xrtcentroid is:
RA (2000): 05 10 47.31
Dec (2000): +64 54 49.76
The centroiding error is 6 arcsec. This is 62 arcseconds from the refined
BAT position (GCN 3576, Markwardt et al., 2005) and
5.5 arcseconds from the tentative UVOT counterpart (GCN 3575, Rol et
al., 2005)
The WT mode data can be fitted by a single power law with an X-ray slope
beta=1.20+/-0.08. The neutral absorption parameter is 1.8e21 1/cm2, which is
slightly higher than the Galactic value (1.3e21 1/cm2; Dickey & Lockman
1990).
The PC mode data agree with this result within the errors.
The light curve shows a fading afterglow with a preliminary
decay slope of alpha=0.85+/-0.08.
The unabsorber 0.3-10.0 keV flux at 1 hour after the burst is estimated to
6.3e-12 ergs/s/cm2
GCN Circular 3587
Subject
GRB 050712, optical observations
Date
2005-07-13T09:07:18Z (20 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
A. Zeh, S. Klose, F. Ludwig, B. Stecklum, Thueringer Landessternwarte
Tautenburg,
report:
We observed the field of GRB 050712 (Grupe et al., GCN 3573) in VRI
with the Tautenburg Schmidt telescope starting 21:15 UT on July 12.
The stacked R-band images show a faint source at the position reported
by Rol et al. (GCN 3575). We estimate R>~20 and note, however, that
this source might also be present on the DSS2 red plates. No source
is visible in I, implying I>~19.
GCN Circular 3596
Subject
GRB050712: Swift UVOT Observation of Afterglow Emission
Date
2005-07-13T17:49:21Z (20 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
This message is in MIME format. The first part should be readable text,
while the remaining parts are likely unreadable without MIME-aware tools.
---1605949312-135341040-1121276953=:1247092
Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE
T. Poole (MSSL), D. Grupe (PSU), A. Breeveld (MSSL),
L. Angelini (GSFC-JHU), J. Greiner (MPE) on behalf of the
Swift UVOT team
The Swift Ultra-Violet/Optical Telescope (UVOT) began
observations of GRB050712 (Grupe et al. GCN 3573; E.Rol
et al. GCN 3575) on 12th July 2005 at 14:02:58 UT. We detect
a source inside the XRT error circle (Falcone et al.
GCN 3574) in the V and U bands. It initially fades, then
brightens before fading below the detection threshold. It is
not detected in the UV filters. No B observations were taken
because of a bright source in the field of view violating the
UVOT count rate limits.
The aperture for optical observations (V and U) was 6 arcsec
and for the UV 12 arcsec. The limiting magnitudes are given
to a 3 sigma limit.
V filter
start exposure mid magnitude
time time time
after =09after
burst burst
(s) (s) (s)
164 100 214 17.97 =B1 0.09 - source detection
313 10 318 17.85 =B1 0.20 - source detection
383 10 388 18.69 =B1 0.20 - source detection
455 10 460 18.13 =B1 0.20 - source detection
526 10 531 18.04 =B1 0.20 - source detection
597 10 602 17.99 =B1 0.20 - source detection
668 49 693 17.83 - limiting magnitude
1207 100 1257 18.01 - limiting magnitude
11414 900 11864 22.15 - limiting magnitude
U filter
start exposure mid magnitude
time time time
after after
burst burst
(s) (s) (s)
282 10 287 17.92 =B1 0.20 - source detection
353 10 358 17.82 - limiting magnitude
425 10 430 17.75 - limiting magnitude
425 10 430 19.47 =B1 0.20 - source detection
496 10 501 18.16 =B1 0.20 - source detection
639 49 664 18.50 - limiting magnitude
996 100 1051 18.74 - limiting magnitude
6477 663 6809 19.83 - limiting magnitude
UVW1
start exposure mid magnitude
time time time
after after
burst burst
(s) (s) (s)
268 107 322 18.49 - limiting magnitude
1970 833 2387 19.62 - limiting magnitude
UVM2 - limiting magnitudes
start exposure mid magnitude
time time time
after after
burst burst
(s) (s) (s)
325 98 374 19.05 - limiting magnitude
1310 46 1333 18.36 - limiting magnitude
4663 1447 723 20.36 - limiting magnitude
UVW2 - limiting magnitudes
start exposure mid magnitude
time time time
after after
burst burst
(s) (s) (s)
298 98 347 19.05 - limiting magnitude
1102 100 1152 20.15 - limiting magnitude
10447 900 10897 21.57 - limiting magnitude
We caution that the instrument is not yet fully calibrated and that the
magnitude limits presented here may need to be refined.
This message may be cited.
---1605949312-135341040-1121276953=:1247092--
GCN Circular 3601
Subject
GRB050712: TNG R-band observations
Date
2005-07-13T21:17:39Z (20 years ago)
From
Nicola Masetti at IASF,CNR,Bologna <masetti@bo.iasf.cnr.it>
E. Maiorano, E. Palazzi, N. Masetti (INAF/IASF, Bo), D. Malesani (SISSA),
P. D'Avanzo (INAF, OAB), G.L. Israel (INAF, OARm), G. Chincarini (Univ.
Milano-Bicocca), L. Stella (INAF, OARm) and M. Pedani (INAF, TNG) report
on behalf on a larger collaboration:
"We observed the field of GRB 050712 (Grupe et al., GCN 3573; Falcone et
al., GCN 3574) with the Italian TNG telescope, located at the Canary
Islands.
The field was observed before twilight, under a seeing of ~1.4 arcsec,
starting on 2003 Jul 13.182 UT (~14.4 h after the GRB). A set of six
images, 300 s exposure time each, was acquired in the R filter.
Within the XRT error circle (Grupe et al., GCN 3579) we find one source,
at a position consistent with that of the OT detected with UVOT (Rol et
al., GCN 3575; see also Zeh et al., GCN 3587).
Assuming R = 15.8 for the USNO-A2.0 star U1500_0409875 at
RA = 05:11:10.51, Dec = +64:55:36.0 (J2000), we measure for the object
above a magnitude R = 21.35 +/- 0.05.
Further analysis is in progress.
This message can be cited."
GCN Circular 3635
Subject
GRB050712: optical limits
Date
2005-07-17T16:28:43Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V.Rumyantsev, E.Sergeeva (CrAO), D.Sharapov, M.Ibrahimov (MAO), G.
Kornienko (UAPhO), A.Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:
We have observed the error box of the Swift GRB050712 (D. Grupe et al., GCN
3573) with 0.4m telescope of Ussuriysk Astrophysical Observatory (UAPhO),
1.5m telescope of Maidanak observatory (MAO), and 0.7m AZT-8 telescope of
CrAO on July, 12-13. We do not detect OT found by T. Poole et al. (GCN
3596) and E. Maiorano et al. (GCN 3601). Upper limits of stacked images
calibrated against of R USNO-A2.0 are following:
Start time, Exposure, Filter, Limiting mag.
(UT) (s)
July,12 15:06 4x60 none 15.0
July,12 23:09 3x180 R 19.0
July,13 00:36 11x60 R 19.5
Detailed analysis of the observed images is underway.
The message may be cited.
GCN Circular 3646
Subject
GRB 050712, Tautenburg optical afterglow observations
Date
2005-07-19T16:22:14Z (20 years ago)
From
Andreas Zeh at TLS Tautenburg <zeh@tls-tautenburg.de>
A. Zeh, D. A. Kann, S. Klose (Thueringer Landessternwarte Tautenburg, Germany),
A. Manning, C. Riddle (Clemson University, SC, USA),
report:
We observed the field of GRB 050712 (Grupe et al. 2005, GCN 3573) with
the Tautenburg 1.34m Schmidt telescope in the R filter at two epochs.
The first set of observations consisted of 10 x 30 second exposures,
mid-exposure time UT 050712.937, i.e. 0.353 days after the GRB. The
second set of observations consisted of 20 x 30 second exposures,
mid-exposure time UT 050713.948, i.e. 1.364 days after the burst.
A comparison of our combined first epoch image with our deeper second
epoch image shows that the potential optical counterpart of the afterglow
(Zeh et al. 2005, GCN 3587) has faded away. Thus, we confirm the earlier
report by Rol et al. (2005, GCN 3575) that the source at coordinates RA,
DEC (J2000) = 5:10:48.1, +64:54:47.6 is the optical counterpart of the
X-ray afterglow (Falcone et al. 2005, GCN 3574; Grupe et al. 2005, GCN 3579).
Assuming R = 15.8 for the USNO-A2.0 star U1500_0409875 at RA, DEC (J2000)
= 05:11:10.51, +64:55:36.0 (Maiorano et al. 2005, GCN 3601), we find the
following magnitudes for the GRB 050712 afterglow:
UT mid t-t_0 (days) mag_Rc
12.937 0.353 20.7 +/- 0.4
13.948 1.364 > 21.5
We find that the decay slope alpha is about 1.2 using the data point by Maiorano
et al. (2005, GCN 3601).
This message may be cited.
GCN Circular 3650
Subject
GRB050712: Radio Observations
Date
2005-07-20T17:37:03Z (20 years ago)
From
Patrick B. Cameron at Caltech <pbc@astro.caltech.edu>
P. B. Cameron reports on behalf of the Caltech-NRAO-Carnegie
collaboration:
"We observed the field of GRB050712 (GCN 3573) with the Very Large Array
at 8.5 GHz on July 17.56 and 19.46. No radio source is detected at the
position of the optical transient (GCN 3575) with a 3-sigma upper limit of
96 uJy from the combined images.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."