GRB 050717
GCN Circular 3652
Subject
GRB 050717: PROMPT RcIc Observations
Date
2005-07-21T00:18:08Z (20 years ago)
From
Daniel E. Reichart at U.North Carolina <reichart@physics.unc.edu>
C. MacLeod, J. Kirschbrown, J. Haislip, M. Nysewander, J. A. Crain, D.
Reichart report on behalf of the UNC team of the FUN GRB Collaboration:
Under the control of Skynet, PROMPT automatically observed the refined XRT
localization of GRB 050717 (Hurkett et al., GCN 3636) beginning 13.0 hours
after the burst.
We do not detect a source within this localization. 3-sigma limiting
magnitudes are based on 5 USNO-B1.0 stars:
Mean Time Integration Filter Limiting Telescope
Since GRB Time Magnitude
13h 40m 58 x 80s Rc 21.7 PROMPT-5
16h 01m 70 x 80s Ic 21.5 PROMPT-5
PROMPT is still being built and commissioned.
GCN Circular 3643
Subject
GRB 050717: Additional LCO observations
Date
2005-07-19T05:56:59Z (20 years ago)
From
Edo Berger at Carnegie Obs <eberger@ociw.edu>
E. Berger, M. Lopez-Morales (Carnegie) and D. Osip (LCO) report on behalf
of a large collaboration:
"We re-observed the XRT error circle (GCN 3636) of GRB 050717 (GCN 3633)
with the Wide-Field Infrared Camera on the du Pont 100-inch telescope at
Las Campanas Observatory on 2005 July 18.98 UT (37.0 hours after the
burst) in K-band. None of the three objects detected in our previous
images within the XRT error circle (GCN 3639) have faded. In addition, we
obtained I-band images with the LDSS-3 instrument on the Magellan/Clay
telescope on 2005 July 18.06 and 18.97 UT (14.9 and 36.8 hours after the
burst, respectively). The same three sources visible in the K-band images
are detected but have not faded.
Please note that the UT date of our first K-band observation was misquoted
in GCN 3639; the correct date is 2005 July 18.01 (13.7 hours after the
burst)."
GCN Circular 3642
Subject
GRB050717
Date
2005-07-18T15:58:40Z (20 years ago)
From
Michael Schwartz at Tenegra Obs. <mbs@tenagraobservatories.com>
Paul Luckas (Tenagra W. Australia) , Odd Trondal (Tenagra Norway) and
Michael Schwartz (Tenagra USA) report:
Following the detection of GRB 050717 by Swift/BAT, we obtained six, 5
minute unfiltered images on 2005 July 18.46 UT (24.5 hours after the
burst), using one of Tenagra observatory's 0.35-m telescopes with AP6
CCD at Perth, Western Australia. No new source was detected within the
XRT error circle (GCN 3636) of GRB050717 (Hurkett et al., GCN 3633) down
to the DSS-2R limiting magnitude.
-Michael Schwartz, on behalf of the Tenagra Observatories GRB follow-up
team.
GCN Circular 3640
Subject
Konus-Wind observation of GRB 050717
Date
2005-07-18T14:22:55Z (20 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team report:
The long hard GRB 050717 (Swift-BAT trigger #146372;
Hurkett et al., GCN 3633, 3636)
triggered Konus-Wind at T0=37857.426s UT (10:30:57.426).
As observed by Konus-Wind it had a steep rise and a long decaying tail.
This tail is seen up to ~50 s after T0.
The burst fluence is ~6.0x10-5 erg/cm2,
peak flux on 64-ms time scale is ~1.2x10-5 erg/cm2 s
(both in the 20 keV - 6 MeV energy range).
The uncertainties in the derived fluence and peak flux are
dominated by uncertainties in high energy part of
the GRB's spectra
(the fluence calculated in 20-350 keV energy range is 1.2x10-5 erg/cm2,
which coincides with the value derived by Swift-BAT)
The time-integrated spectrum (from T0 to T0+51.712 s)
is well fitted (in 20 keV-6 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) exp(-E/E0)
with alpha = 1.12 (-0.17, +0.13),
and E0 = 2150 (-1070, +2300) keV.
The peak energy Ep = 1890 (-760, +1600) keV.
The spectrum can also be fitted by a GRBM (Band) model, but in this
case the high energy photon index beta = -1.71 (-0.95, +0.21)
and only lower limit on Ep can be found: Ep >= 900 keV.
The spectrum of the main peak (from T0 to T0+5.376 s)
is well fitted (in 20 keV-6 MeV range)
by a power law with exponential cutoff model
with alpha = 1.06 � 0.10,
and E0 = 2470 (-850, +1480) keV.
The peak energy Ep = 2300 (-670, +1100) keV.
(For GRBM model, beta = -1.73 (-0.33, +0.21)).
All quoted unceratinties are at 90% confidence level.
GCN Circular 3639
Subject
GRB 050717: LCO near-IR observations
Date
2005-07-18T05:25:21Z (20 years ago)
From
Edo Berger at Carnegie Obs <eberger@ociw.edu>
E. Berger and M. Lopez-Morales (Carnegie) report on behalf of a larger
collaboration:
"We observed the XRT error circle (GCN 3636) of GRB 050717 (GCN 3633) with
the Wide-Field Infrared Camera on the du Pont 100-inch telescope at Las
Campanas Observatory on 2005 July 19.01 UT (37.7 hours after the burst) in
K-band. A total of 810 seconds were obtained in good seeing conditions.
Within the 6-arcsec radius XRT error circle we find 4 sources of which one
is also visible in 2MASS K-band images. The other three sources have
magnitudes of 18.1, 18.7, and 19.2 in comparison to several 2MASS stars;
the 3-sigma limiting magnitude of our image is about 19.4. At this point
we do not have any evidence for fading in any of the three sources.
Further observations are planned."
GCN Circular 3638
Subject
Swift/UVOT Observations of GRB 050717
Date
2005-07-17T17:54:35Z (20 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
A. Blustin (MSSL), C. Hurkett (U. Leicester), A. Smale (NASA HQ),
L. Cominsky (Sonoma State U.) report on behalf of the Swift
UVOT team:
Using summed images from Swift/UVOT of the field of
GRB 050717 (Hurkett et al., GCN 3633), taken from 78
seconds after the BAT trigger, no new source is detected
within the refined XRT error circle (Hurkett et al.,
GCN 3636) in any of the six filters down to the following
3-sigma magnitude upper limits:
Filter Exposure (s) T_mid (s) 3-sig limit
V 168 424 19.00
B 75 524 19.59
U 78 511 19.34
UVW1 78 498 18.62
UVM2 78 483 18.79
UVW2 68 498 18.73
where T_mid is the mid-point of the summed observation.
We caution that the instrument is not yet fully
calibrated and that the magnitude limits presented here
may need to be refined.
GCN Circular 3637
Subject
GRB 050717: Swift-BAT refined analysis
Date
2005-07-17T17:39:19Z (20 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
J. Cummings (GSFC/NRC), L. Barbier (GSFC), S. Barthelmy (GSFC),
E. Fenimore (LANL), N. Gehrels (GSFC), K. Gendreau (GSFC),
D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
P. Meszaros (PSU), T. Mitani (ISAS), 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:
At 10:30:52.21 UT Swift-BAT detected GRB 050717 (trigger=146372)
(GCN Circ 3633, C. Hurkett et al.). The refined BAT ground position
is (RA,Dec) = 214.352, -50.541, [deg; J2000] +- 3 arcmin, (90%
containment). The partial coding was 55%.
The masked-weighted light curve shows a large peak (starting at T+2.4 sec
and reaching a maximum at T+2.8 sec), followed by an exponential decay
with several smaller peaks. There are two much smaller precursor peaks
at T+0 and T+0.7 sec, each with a 15-350 keV fluence of ~7 x 10^-8 erg/cm2.
BAT triggered on the first these two precursor peaks. T90 (15-350 keV) is
(86 +- 2) sec (estimated error including systematics).
The power-law photon index of the time-averaged spectrum is 1.42 +- 0.05.
The fluence in the 15-350 keV band is (1.27 +- 0.05) x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+2.8 sec in the 15-350
band is (8.5 +- 0.4) ph/cm2/sec. All the quoted errors are at the 90%
confidence level.
GCN Circular 3636
Subject
GRB 050717: Refined XRT analysis.
Date
2005-07-17T17:22:27Z (20 years ago)
From
Cheryl Pauline Hurkett at Leicester U <cph9@star.le.ac.uk>
C. Hurkett, K. Page (U. Leicester), D. Burrows (PSU), M. Chester (PSU), L.
Angelini (GSFC-JHU) and N. Gehrels (GSFC) report for the Swift XRT team:
We have analysed the XRT data for GRB 050717 (GCN 3633, Hurkett et al)
starting at 91s seconds after the trigger. The new refined coordinates are
(J2000);
RA 14:17:25.0
Dec -50:31:58.9
with an uncertainty of 6 arcseconds (90% containment). This position is 14
arcsecond from the position reported in GCN 3634 (Kennea et al).
XRT observations began in Windowed Timing (WT) mode 91 seconds after the
trigger before going into PC mode at 310s. The lightcurve has initial
decay index of 1.95 (+0.18/-0.11), breaking at ~318s into a decay index of
1.29 (+/-0.08).
The spectrum between 91s and 310s seconds after the trigger (WT data) has
an average photon index of 1.61 (+0.11/-0.10), with the absorption fixed
at its Galactic value of 2.3e21 cm^-2 and an indication of an excess
absorption of 2.66e21 (+0.06e21/-0.05e21) cm^-2. The mean unabsorbed flux
in WT mode at 201s (mean time) is 7.74 (+0.21/-0.24) x e-10 erg/cm^2/s in
the 0.5-10.0 keV energy range.
GCN Circular 3634
Subject
GRB050717: Swift XRT position
Date
2005-07-17T12:59:54Z (20 years ago)
From
Jamie A. Kennea at PSU/Swift-XRT <kennea@astro.psu.edu>
J.A. Kennea, D.N. Burrows (PSU), C. Hurkett, K. Page (U. Leicester) and
N. Gehrels (GSFC) report for the Swift XRT Team:
We have performed an initial analysis of the downlinked XRT data from
GRB050717 (GCN 3633), and have found a fading, previously uncatalogued,
point source in the field at the following coordinates:
RA(J2000): 14:17:24.9,
Dec(J2000): -50:32:13.2
with an estimated uncertainty of 6 arcseconds radius (90% containment).
This source lies 50 arcseconds from the BAT position reported in GCN 3633.
GCN Circular 3633
Subject
Swift detection of GRB 050717
Date
2005-07-17T11:28:50Z (20 years ago)
From
Cheryl Pauline Hurkett at Leicester U <cph9@star.le.ac.uk>
C. Hurkett, K. Page, (U. Leicester), J. Kennea, D. Burrows (PSU), A.
Blustin (MSSL), L. Barbier (GSFC), C. Markwardt (GSFC/UMd), A. Parsons
(GSFC) and N. Gehrels (GSFC) report on behalf of the Swift team;
At 10:30:52.21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB 050717 (trigger # 146372). The BAT on-board
calculated location is RA, Dec 214.332, -50.539 (14h 17m 20s, -50d 32'
21") (J2000) with an uncertainty of 3 arcmin (radius, 4-sigma, including
estimated systematic uncertainty). The BAT light curve showed an initial
spike, then a strong peak followed by a decay out to about 20 seconds
(FRED). The peak count rate was measured by BAT to be ~16000 counts/sec at
T+4 sec in the 15 - 350 keV band.
The spacecraft slewed immediately and the XRT began observing the burst at
10:32:11.49 UT (approximately 79 seconds after the BAT trigger). The XRT
was unable to centroid on the burst, however, the downlinked X-ray
spectrum and lightcurve show that there is a bright X-ray object in the
field that appears to be fading.
The Swift Ultra Violet/Optical Telescope (UVOT) observations began at
10:32:10.7 UT (78 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 128 sec after the BAT trigger.
Based on comparisons to the DSS, we detect no new source within the BAT
error circle. The 3-sigma upper limit in the V-filter is approximately
18.71 mag.