GRB 050803
GCN Circular 3748
Subject
GRB050803: Swift-BAT detection of a very long burst
Date
2005-08-03T20:10:23Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
D.L. Band (GSFC-UMBC), S. Barthelmy (GSFC), P. Boyd (GSFC-UMBC), P. Brown (PSU),
D. Burrows (PSU), M. Chester (PSU), J. Cummings (GSFC/NRC), N. Gehrels (GSFC),
C. Markwardt (GSFC), J. Nousek (PSU), K. Page (U. Leicester), C. Pagani (PSU),
D. Palmer (LANL), T. Sakamoto (GSFC), J. Racusin (PSU)
on behalf of the Swift team:
At 19:14:00 UT, Swift-BAT triggered and located GRB050803 (trigger=148833).
The spacecraft slewed immediately. The BAT on-board calculated location
is RA,Dec 350.650d,+5.800d {23h 22m 36s,+05d 48' 00"} (J2000), with an
uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light
curve shows a multi-peak structure with a total duration of at least 150 sec.
There is a fairly strong short peak at T+145 sec. The peak count rate was
~1000 counts/sec (15-350 keV), at ~80 seconds after the trigger.
The XRT began observing at 19:16:31.6 UT, 151.6 seconds after the BAT trigger.
An uncatalogued, rapidly fading X-ray source was detected at an RA and Dec of
23h 22m 37.7s, 05d 47m 7.4s (J2000; 90% containment uncertainty of 6 arcsec),
which is 58.4" from the BAT position.
The UVOT began settled exposures about 3 minutes after the burst. Using a
preliminary ground-processed 100-sec image, the upper limit is 18.5 (3 sigma)
in the V band.
We are currently in the portion of the orbits where the spacecraft does not
pass over the Malindi downlink station. Therefore, it will be ~4 hours
before we have access to the full data set for the refined analyses.
GCN Circular 3750
Subject
GRB050803: MASTER optical observations
Date
2005-08-03T20:47:19Z (20 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov,
A.Belinski,
E.Gorbovskoy, N.Tyurina, V.Vladimirov
Sternberg Astronomical Institute, Moscow
198 sec after SWIFT GRB050803 detection (Tirgger_Num 148833) MASTER
robotic telescope (http://observ.pereplet.ru) had imaging the
corresponding area of the sky under the bad weather conditions on the
evening sky near the horizont.
We have first image by 200 mm camera with grisma up to 9m.
The first
unfiltred image on 355 mm camera was made at 28 min (19h32m25s UT))after
GRB time due to
technical problems(the limit is 14.5 m).
There is no OT.
Observations are continued.
This work is supported by Moscow Union "OPTICA" and RFFI 04-02-16411.
Mailto: lipunov@sai.msu.ru
GCN Circular 3751
Subject
GRB 050803: TAROT optical limits
Date
2005-08-03T22:36:47Z (20 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz, A. (CESR-OMP), Boer M. (OHP-OAMP),
Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 050803 detected by SWIFT
(trigger 148833) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
Trigger occured at twilight and first image was acquired
60.9 min after the GRB. The field had an elevation of
5 degrees above horizon at the begining of the observations
and then increased.
We detected no new source comparing our unfiltered images
with the DSS-2 ones. Following limits comes to co-additions
of several sets of exposures.
Tmid (min since GRB) Exp (s) R-Mag
60.9 - 63.4 90 >16.0
83.9 - 102.8 1080 >17.8
83.9 - 156.1 3600 >18.7
Limiting magnitude were estimated with the nearby USNO-B1 stars.
This message can be cited.
GCN Circular 3752
Subject
GRB 050803: early Swift XRT analysis results
Date
2005-08-04T03:50:32Z (20 years ago)
From
Judith Racusin at PSU <racusin@astro.psu.edu>
J. Racusin (PSU), C. Pagani (INAF-OAB), D. Burrows (PSU), K. Page (U.
Leicester), on behalf on the Swift XRT team:
We have analyzed the first 3 orbits of Swift XRT data from GRB 050803
(Band et al., GCN 3748). The refined coordinates from the downlinked
ground processed data of the X-ray afterglow are:
RA(J2000): 23h 22m 37.8s
Dec(J2000): +5d 47' 5.5"
This position is 60 arcseconds from the BAT position given in GCN 3748
(Band et al.), and 2.1 arcseconds from the on-board determined XRT
position reported in GCN 3748. We estimate an uncertainty of 6 arcseconds
radius (90% containment).
Data in Window Timing (WT) mode began at 19:16:40 UT, 160 seconds after
the BAT trigger, and continued for 84s before switching into Photon
Counting (PC) mode. The 0.3-10 keV afterglow light curve shows a rapidly
fading X-ray source which can be fitted with a power law of slope
alpha=-5.4+/-0.1 up to a break around 290 s, after which the light curve
flattens where it can be fitted with a power law of slope
alpha=-0.53+/-0.02 as far as current data extends.
The predicted flux at 24 hours after the trigger is 2.96E-12 erg cm^-2
s^-1.
A preliminary spectral fit to this data gives a spectral power law photon
index of 1.8 +/- 0.1 with nH=(19.8+/-3.2)E20 cm^-2. This is significantly
higher than the Galactic nH along the line of sight which is 5.6E+20
cm^-2.
GCN Circular 3753
Subject
GRB 050803: Magellan Observations
Date
2005-08-04T06:36:17Z (20 years ago)
From
Edo Berger at Carnegie Obs <eberger@ociw.edu>
E. Berger, M. Geha, I. Thompson (Carnegie Observatories) report:
"On 2005, August 4.234 UT we imaged the XRT error circle (GCN 3752) of GRB
050803 (GCN 3748). Within the error circle we find a single object
located at (J2000):
RA = 23:22:38.0
DEC= 05:47:02.3
with an uncertainty of about 0.5" in each coordinate. The source appears
to be extended in our image, and has a magnitude of I ~ 22 mag. We have
no indication of variability at this point. We note that this object may
be the afterglow superposed on a relatively bright host galaxy, or an
unrelated object."
GCN Circular 3754
Subject
GRB 050803, optical observations
Date
2005-08-04T08:27:03Z (20 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
S. Klose and C. Hoegner, Thueringer Landessternwarte Tautenburg,
report:
Tautenburg observed the error box of GRB 050803 (Band et al. 2005,
GCN 3748; Racusin et al. 2005, GCN 3752) between 22:23 UT and 22:45 UT,
i.e., about 3 hrs after the burst. Several images were taken, mostly
in the I-band. Observations had to be finished after 22:45 UT because
of bad weather. We do not detect the afterglow candidate reported by
Berger et al. (2005, GCN 3753) down to about I=19.
GCN Circular 3755
Subject
GRB050803: MASTER further analys
Date
2005-08-04T09:45:28Z (20 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski,
E.Gorbovskoy, A.Krylov, G.Borisov, V.Vladimirov
Sternberg Astronomical Institute, Moscow Union "Optic"
MASTER (http://observ.pereplet.ru) responded to GRB 050801 (Swift
trigger 148833, GCN 3752). The first image was at 198 sec after SWIFT
GRB050803 detection (19:14:00.34 UT) under the bad weather
conditions on the evening sky near the horizont (GCN3750). We have the
first low resolution spectra (50A) image of the error box by 200 mm
camera up to 9m.
The first unfiltred image on 355 mm camera was made at 28 min
(19h32m25s UT) after GRB time due to technical problems (the limit is
14.6 m).
The magnitude close to R.
UT timme GRB Time (min) Exp Optical limit
19:32:25.65 18.4 30 s 14.6
19:49:00.31 35.0 30 s 17.0
19:49 - 20:08 35.0 - 54.0 12x30 s 18.6
The JPG-images are available at
http://observ.pereplet.ru/images/GRB050803/all.jpg .
Imoprtant note: this is the second night Swift GRB accessible alert during
this year at Moscow region. The first alert was in rain.
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
GCN Circular 3757
Subject
GRB 050803: Swift-BAT refined analysis
Date
2005-08-04T15:06:33Z (20 years ago)
From
Craig Markwardt at NASA/GSFC/UMD <craigm@milkyway.gsfc.nasa.gov>
A. Parsons (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC),
M. Chester (PSU), J. Cummings (GSFC/NRC), E. Fenimore (LANL),
N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), F. Marshall (GSFC), D. Palmer (LANL),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
At 19:14:00 UT Swift-BAT detected GRB 050803 (trigger=148833) (GCN
Circ 3748, Band, et al.). The refined BAT ground position is (RA,Dec)
= 350.658, +5.778 {23h22m37.9s, +05d46'40.8"} [deg; J2000] +-3 arcmin,
(95% containment). The partial coding was 46%.
The light curve has one broad and one narrow peak, of approximately
equal peak count rates. The broad peak extends from T+60 to T+100
sec, with a roughly symmetrical shape. The narrow peak is centered at
T+148 sec, with a duration of ~2 sec. There is some inter-peak
emission and some emission after the narrow peak for ~20 sec.
The formal T90 is 85 +- 10 sec, and T50 is
30 +- 5 sec (15-350 keV; estimated error including systematics).
However, due to the large spread between the two peaks, a more
accurate measure of the total burst duration is ~110 sec.
We note this burst was the result of a 72-sec long BAT Image Trigger
whose integration started ~55 sec before the onset of the broad peak
(i.e. the integration included ~15 sec of that first peak). Hence,
the actual start of the burst ocurred 19:14:55 UT.
A simple power law fit to the time averaged spectrum produces a photon
index of 1.5 +- 0.1. The fluence is (3.9 +- 0.3) x 10^-6 erg/cm2.
The 1-s peak photon flux measured from T+147 sec is (1.5 +- 0.2)
ph/cm2/s (this corresponds to the narrow peak).
The narrow peak contains ~5% of the total fluence. Its photon index
is (1.4 +-0.2), consistent with the overall average spectrum.
All fluxes and fluences are quoted for the 15-350 keV band, and the
quoted errors are at the 90% confidence level.
GCN Circular 3758
Subject
GRB 050803: Keck Observations
Date
2005-08-04T15:25:42Z (20 years ago)
From
Josh Bloom at UC Berleley <jbloom@astron.berkeley.edu>
GRB 050803: Keck Observations
J. S. Bloom, D. Perley, R. Foley (UCB), J. X. Prochaska (UCSC), H. W.
Chen (MIT), & D. Starr (Gemini) report:
"R-band imaging of field of GRB 050803 (GCN 3748; 3757) with ESI/Keck
II shows several faint sources in the uncertainty circle of the XRT
(GCN 3752), including the extended object noted in GCN 3753.
Spectroscopy of this source reveals it to be a star forming galaxy at
z=0.422, based upon redshifted [OII], [OIII], and H-beta emission
lines. We expect ongoing analysis to improve the precision of this
redshift."
This message may be cited.
GCN Circular 3759
Subject
GRB050803: Optical/UV Upper Limits from Swift-UVOT
Date
2005-08-04T17:06:57Z (20 years ago)
From
Peter Brown at PSU <pbrown@astro.psu.edu>
GRB050803: Optical/UV Upper Limits from Swift-UVOT
P. J. Brown (PSU), D.L. Band (GSFC-UMBC),
P. Boyd (GSFC-UMBC), J. Norris (GSFC),
K. Hurley (Berkeley), N. Gehrels (GSFC),
report on behalf of the Swift-UVOT Team:
Swift detected and slewed immediately to the
position of GRB050803 (trigger=148833;
Band et al. GCN 3748). UVOT began settled
observations at 19:17:05.2 UT, 185 seconds
after the trigger. No sources are detected
within the revised XRT error circle
(Racusin et al GCN 3752) in any of our images.
The following are 3 sigma upper limits at the
indicated epochs.
Filter Tmid(sec) Tmid(h) Exp(sec) UppLim(3-sigma)
V 235.09 0.07 99.78 18.8
V 365.14 0.1 9.76 17.5
V 1357.88 0.38 99.72 18.5
V 11900.74 3.31 899.76 20.0
B 336.31 0.09 9.77 18.5
B 1148.34 0.32 99.77 19.7
B 6919.71 1.92 693.82 20.7
B 18490.49 5.14 695.69 20.7
U 322.1 0.09 9.76 18.3
U 1043.66 0.29 99.77 19.5
U 6115.3 1.7 899.77 20.7
U 17685.21 4.91 899.77 20.7
UVW1 308.4 0.09 9.79 18.7
UVW1 5208.39 1.45 899.77 21.1
UVW1 16778.3 4.66 899.76 21.1
UVM2 294.29 0.08 9.79 18.5
UVM2 1446.35 0.4 68.22 19.5
UVM2 12705.06 3.53 694.85 20.9
UVW2 351.49 0.1 9.78 19.4
UVW2 1253.64 0.35 99.77 20.2
UVW2 10993.89 3.05 899.78 21.5
In addition, no sources are detected within the
XRT error circle when the above images are summed
together, including those reported by Bloom et al
(GCN 3758) and Berger et al (GCN 3753).
These magnitudes are based on preliminary zero-points,
measured in orbit, and will require refinement with
further calibration.
GCN Circular 3760
Subject
GRB050803: CrAO optical observations, possible OT candidate
Date
2005-08-04T17:27:05Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Pavlenko, Yu. Efimov, A. Shlyapnikov, A. Baklanov, V. Rumyantsev (CrAO),
A.Pozanenko (IKI), M. Ibrahimov (MAO) on behalf of larger GRB follow up
collaboration report:
On August 3, 21:20 (UT) we observed XRT error box (Racusin et al., GCN 3752)
of GRB050803 (Band et al., GCN 3748) with 2.6m Shain telescope (CrAO).
Within XRT error box we detect the object noted in GCN 3753 (Berger et al.).
The magnitude of the object is R = 20.72 +/- 0.22 at mid time August 3,
(UT) 21:50 and was calibrated against of USNO B1.0 star 0957-0591541
(R=19.31). Taking into account the I ~ 22 mag at August 4.234 (UT) repored
by Berger et al. (GCN 3753)one can suggest that the object is fading and can
be considered as possible OT candidate.
This message may be cited.
GCN Circular 3763
Subject
GRB 050803: RTT150 optical observations
Date
2005-08-04T20:24:56Z (20 years ago)
From
Rodion Burenin at IKI, Moscow <rodion@hea.iki.rssi.ru>
R. Burenin, A. Tkachenko, M. Pavlinsky, R. Sunyaev (IKI),
I. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), A. Alpar (SabUni),
I. Bikmaev, N. Sakhibullin (KSU/AST)
report:
We observed error box of GRB 050803 (GCN 3748) with Russian-Turkish
1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory,
Turkey). The observations were started at 20:00 UT, i.e. 0.77 hours
after the burst. We observed the field till the dawn, which occurs at
2:00 UT, Aug 4.
We made a set of 30--60s exposures in R. At the position of X-ray
afterglow we found the object mentioned in GCN 3753, as well as one
other fainter object at the edge of XRT error box, probably one of those
mentioned in GCN 3758.
The first object is definitely extended. It have R=~22.2 and is stable
within ~10\% during whole our observations and therefore can not be
proposed as possible OT candidate (GCN 3760). Brighter magnitude in GCN
3760 was obtained because the magnitude of their reference star is
measured with large error in USNO-B1.
Second object is close to the detection limit in our combined image,
which is R=~25.5, but is also extended.
Our finding chart can be found at:
http://hea.iki.rssi.ru/~rodion/050803/r.jpg
We also note, that there is nearby foreground galaxy group in the field.
This message may be cited.
GCN Circular 3764
Subject
GRB050803: Radio Observation
Date
2005-08-04T20:39:49Z (20 years ago)
From
Patrick B. Cameron at Caltech <pbc@astro.caltech.edu>
P. B. Cameron (Caltech) reports on behalf of the Caltech-NRAO-Carnegie
collaboration:
"We observed the field of GRB050803 (GCN 3748) with the Very Large Array
at 8.5 GHz beginning August 4.44 UT. No radio source is detected at the
position of the optical source (GCN 3753) with a 2-sigma upper limit of
102 uJy. Further observations are planned.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 3774
Subject
GRB050803, optical observations
Date
2005-08-06T04:53:17Z (20 years ago)
From
T.P. Prabhu at Indian Astro. Obs. <tpp@crest.ernet.in>
S. Ramya, D.K. Sahu, P.S. parihar and T.P. Prabhu communicate on behalf of
a larger GRB collaboration group:
The field of GRB050803 was observed with the 2-m Himalayan Chandra
Telescope of Indian Astronomical Observatory, Hanle, on 2005 August 3,
20:30 UT (300s+600s+600s) and 22:18 UT (600s). The extended object
mentioned in GCN 3753, 3760, 3763 is the brightest source in the XRT
error box. Its magnitude with respect to USNO B1.0 star 0957-0591541
(R=19.31) was constant at R=20.9+/-0.1 mag at both the epochs.
This message may be cited.
GCN Circular 3780
Subject
GRB 050803: PROMPT BVRcIc Observations
Date
2005-08-08T01:56:17Z (20 years ago)
From
Josh Haislip at U.North Carolina <haislip@physics.unc.edu>
J. Haislip, D. Reichart report on behalf of the UNC team of the FUN GRB
Collaboration:
Under the control of Skynet, PROMPT automatically observed the localization
of GRB 050803 (Band et al., GCN 3748) beginning 7.1 hours after the burst
in repeating blocks of BVRcIc (two simultaneously).
We do not detect any new sources within or around the XRT localization.
In a 54 x 40 sec integration of mean epoch 10.0 hours after the burst, we
measure a 3-sigma limiting magnitude of Rc = 21.4, based on 3 USNO-B1.0
stars.
PROMPT is still being built and commissioned.
GCN Circular 3783
Subject
GRB050803: CrAO optical observations, no OT candidate
Date
2005-08-10T17:58:30Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Pavlenko, A. Shlyapnikov, Yu. Efimov, A. Baklanov, V. Rumyantsev (CrAO),
A.Pozanenko (IKI), D. Sharapov, M. Ibrahimov, (MAO) on behalf of larger GRB
follow up collaboration report:
We observed XRT error box (Racusin et al., GCN 3752) of GRB050803 (Band
et al., GCN 3748) with 2.6m Shain telescope (CrAO) on August 3 (Pavlenko et
al., GCN 3760) and August 4. The object mentioned in GCN 3753 (Berger et
al.) is detected in both epochs. We recalibrated our data (Pavlenko et al.,
GCN 3760) and found the R-magnitude of the object:
Mid time Aug.3, (UT)22:02 R = 22.10 +/- 0.10
Mid time Aug.4, (UT)21:41 R = 22.05 +/- 0.05
which is in agreement with photometry reported in GCN 3763 (Burenin et al.).
Since no variability of the proposed object is detected it cannot be
considered as OT candidate.
Meanwhile extended object is detected in the FOV with coordinates RA(J2000)=
23:22:38.73 Dec(J2000)=05:47:12.4 at Aug.3, (UT) 22:02 with R=21.78 +- 0.03
which is not visible on Aug. 4 observations. Detailed analysis shows that it
is an asteroid with velocity ~0.005 arcsec/sec toward N-W. The detected
asteroid in not presented in the catalogs of Minor Planet Center
(http://cfa-www.harvard.edu/cfa/ps/mpc.html).
This message may be cited.