- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Mon 17 Sep 07 07:34:17 UT
NOTICE_TYPE: Swift-BAT GRB Position
TRIGGER_NUM: 291292, Seg_Num: 0
GRB_RA: 293.925d {+19h 35m 42s} (J2000),
294.022d {+19h 36m 05s} (current),
293.295d {+19h 33m 11s} (1950)
GRB_DEC: +2.413d {+02d 24' 47"} (J2000),
+2.430d {+02d 25' 50"} (current),
+2.301d {+02d 18' 05"} (1950)
GRB_ERROR: 3.00 [arcmin radius, statistical only]
GRB_INTEN: 16450 [cnts] Image_Peak=2508 [image_cnts]
TRIGGER_DUR: 1.024 [sec]
TRIGGER_INDEX: 146 E_range: 25-100 keV
BKG_INTEN: 35233 [cnts]
BKG_TIME: 27221.77 SOD {07:33:41.77} UT
BKG_DUR: 8 [sec]
GRB_DATE: 14360 TJD; 260 DOY; 07/09/17
GRB_TIME: 27236.68 SOD {07:33:56.68} UT
GRB_PHI: 42.48 [deg]
GRB_THETA: 20.36 [deg]
SOLN_STATUS: 0x3
RATE_SIGNIF: 167.16 [sigma]
IMAGE_SIGNIF: 24.76 [sigma]
MERIT_PARAMS: +1 +0 +0 +1 +2 +29 +0 +1 +48 +1
SUN_POSTN: 174.53d {+11h 38m 07s} +2.37d {+02d 21' 57"}
SUN_DIST: 119.32 [deg] Sun_angle= -8.0 [hr] (East of Sun)
MOON_POSTN: 234.16d {+15h 36m 38s} -24.72d {-24d 43' 11"}
MOON_DIST: 64.03 [deg]
MOON_ILLUM: 28 [%]
GAL_COORDS: 40.19, -8.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 296.26, 23.70 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: SWIFT-BAT GRB Coordinates.
COMMENTS: This is a rate trigger.
COMMENTS: A point_source was found.
COMMENTS: This does not match any source in the on-board catalog.
COMMENTS: This does not match any source in the ground catalog.
COMMENTS: This is a GRB.
COMMENTS: This trigger occurred at longitude,latitude = 132.45,-9.57 [deg].
- red DSS finding chart
ps-file
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Mon 17 Sep 07 07:37:25 UT
NOTICE_TYPE: Swift-BAT GRB Lightcurve
TRIGGER_NUM: 291292, Seg_Num: 0
GRB_RA: 293.925d {+19h 35m 42s} (J2000),
294.022d {+19h 36m 05s} (current),
293.295d {+19h 33m 11s} (1950)
GRB_DEC: +2.413d {+02d 24' 47"} (J2000),
+2.430d {+02d 25' 50"} (current),
+2.301d {+02d 18' 05"} (1950)
GRB_DATE: 14360 TJD; 260 DOY; 07/09/17
GRB_TIME: 27236.68 SOD {07:33:56.68} UT
TRIGGER_INDEX: 146
GRB_PHI: 42.48 [deg]
GRB_THETA: 20.36 [deg]
DELTA_TIME: -50.00 [sec]
TRIGGER_DUR: 1.024 [sec]
SOLN_STATUS: 0x3
RATE_SIGNIF: 167.16 [sigma]
IMAGE_SIGNIF: 24.76 [sigma]
LC_URL: sw00291292000msb.lc
SUN_POSTN: 174.53d {+11h 38m 08s} +2.36d {+02d 21' 54"}
SUN_DIST: 119.32 [deg] Sun_angle= -8.0 [hr] (East of Sun)
MOON_POSTN: 234.18d {+15h 36m 44s} -24.73d {-24d 43' 34"}
MOON_DIST: 64.01 [deg]
MOON_ILLUM: 28 [%]
GAL_COORDS: 40.19, -8.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 296.26, 23.70 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: SWIFT-BAT GRB Lightcurve.
COMMENTS:
COMMENTS: The next comments were copied from the BAT_POS Notice:
COMMENTS: This is a rate trigger.
COMMENTS: A point_source was found.
COMMENTS: This does not match any source in the on-board catalog.
COMMENTS: This does not match any source in the ground catalog.
COMMENTS: This is a GRB.
COMMENTS: This trigger occurred at longitude,latitude = 132.45,-9.57 [deg].
- GCN Circular #6791
J. R. Cummings (NASA/UMBC), A. P. Beardmore (U Leicester),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (NASA/ORAU) and M. Stamatikos (NASA/ORAU) report on
behalf of the Swift Team:
At 07:33:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070917 (trigger=291292).
The BAT on-board calculated location is RA, Dec 293.925, +2.413 which is
RA(J2000) = 19h 35m 42s
Dec(J2000) = +02d 24' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a FRED
structure with a duration of about 5 sec. The peak count rate
was ~22000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Because Swift is in the process of returning to normal operations,
automatic slewing to GRBs is currently disabled. Therefore, there
are no prompt XRT or UVOT observations of this burst.
Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.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 Circular #6792
J. Tueller (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),
T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-120 to T+129 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 070917 (trigger #291292)
(Cummings, et al., GCN Circ. 6791). The BAT ground-calculated position is
RA, Dec = 293.923, 2.420 deg which is
RA(J2000) = 19h 35m 41.5s
Dec(J2000) = 02d 25' 12"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 79%.
The mask-weighted lightcurve starts at ~T-5 sec, has a sharp rise from
T-0.1 sec to ~T+0.3 sec, peaks at ~T+0.4 sec, and then approximately
exponentially decays to background at ~T+30 sec.
T90 (15-350 keV) is 7.3 +- 0.2 sec (estimated error including systematics).
The time-averaged spectrum from T-0.1 to T+11.4 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.52 +- 0.05. The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.21 sec in the 15-150 keV band
is 8.5 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
- GCN Circular #6793
K. Misra, S. B. Pandey and Rupak Roy (ARIES, NainiTal, India, on bahalf
of larger Indian GRB collaboration)
We have imaged the field of Swift GRB 070917 with the 1.04m telescope at
NainiTal ~ 7.5 hours after the burst (Cummings et al. GCN 6791).
Observations were performed in R band (5*300 sec) in poor sky conditions.
We notice that the field is crowded and a considerable amount of
extinction (E(B - V) = 0.45 mag) is there in the burst direction. Visual
comparison with DSS-II plate does not show any new source within the
refined error-box (Tueller et al. GCN 6792). Photometry of the co-added
frame put a 3 sigma upper limit of ~20.5 mag in comparison to the nearby
USNO A2.0 star 0900-15768267 (R mag 16.6)
This message may be cited.
- GCN Circular #6794
T. Ishimura, T. Shimokawabe, N. Vasquez, Y. Yatsu, Y. Kudou and
N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB070917 (Cummings et al. GCN 6791)
with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting
at 09:46:58 UT, 2.2 hours after the trigger.
Although the observation was performed in three bands (Ic, Rc, and g'),
only the data in Ic band are usable for reliable comparison to
catalogued sources because of the poor sky condition in the dusk
with thin clouds.
We did not detect a new source in the BAT error circle. The 3-sigma
limiting magnitude based on USNO-B1.0 (I-band) stars is following.
Filter start time end time Exposure Mag (3-sigma UL)
-----------------------------------------------------------
Ic 09:46:58 10:08:08 13 x 60s 17.8
-----------------------------------------------------------
- GCN Circular #6795
W. Li, University of California, Berkeley, on behalf of the KAIT GRB
team, report:
The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT)
at Lick Observatory observed GRB 070917 detected with Swift
(Trigger 291292; Cummings et al. GCN 6791, Tueller et al. GCN
6792). The automatic sequence started at 07:34:52, 56 s after
the burst. The BAT location has been monitored in V, I, and
clear filters, with varying exposure times. Our image processing
pipeline did not find any new objects within the BAT error circle,
with the following photometry limits (calibrated with USNO B1.0).
These magnitudes have not been corrected for Galactic extinction
(E(B - V) = 0.45 mag; Misra et al. GCN 6793).
======================================================================
Start UT t(GRB) Filter Exp(s) 3sigma-limit
07:34:52 56s clear 5.0 16.8
07:34:58 62s clear 5.0 16.7
07:35:04 68s clear 5.0 16.8
07:35:10 74s clear 5.0 16.7
07:35:17 81s clear 5.0 16.9
07:35:48 112s V 20.0 16.2
07:36:19 143s I 20.0 17.3
07:36:49 173s clear 20.0 17.9
========================================================================
More images, mostly 20 s exposures in the I and clear filters,
have been obtained. No obvious OA was found in the BAT error
circle to a limiting magnitude of 16.9 - 18.0 mag, at
t= 204 s to 2204 s after the burst.
This message may be cited.
- GCN Circular #6796
P.A. Evans, A.P. Beardmore, K.L. Page, R.L.C. Starling (U. Leicester)
and J.R. Cummings (NASA/UMBC) report on behalf of the Swift-XRT team:
We have analysed 2.3 ks of Swift XRT data for GRB 070917 (Cummings et
al. GCN Circ 6791) beginning 35 ks after the trigger. The data are
entirely in Photon Counting mode. An uncatalogued X-ray source is
clearly detected at RA, Dec= 293.91913, +2.41055 degrees, which is
equivalent to:
RA (J2000) = 19h 35m 40.59s
Dec(J2000) = +02d 24' 38.0"
with an estimated uncertainty of 8.0 arcsec (radius, 90% containment
including boresight uncertainty). This is 37 arcsec from the BAT refined
position (Tueller et al. GCN Circ 6792). The source has a count rate of
0.016 counts s^-1. At present we are unable to determine whether the
source is fading, however observations are ongoing.
Using the C-statistic in xspec we fit the PC mode spectrum from
T0+35000-42000 s with an absorbed power-law. The absorption is
consistant with the Galactic value of 1.73e21 cm^-2 (Kalberla et al.
2005). The spectral slope is gamma=1.17 (+0.44/-0.45), which is
consistent with the BAT value of 1.52 +/- 0.04. The observed
(unabsorbed) flux is 1.31e-12 (1.44e-12) erg/cm^2/s.
This circular is an official product of the Swift team.
- GCN Circular #6798
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
and T. Cline on behalf of the Konus-Wind team report:
The long GRB 070917 (Swift-BAT trigger #291292:
Cummings et al., GCN 6791; Tueller et al., GCN 6792) triggered
Konus-Wind at T0=27239.542 s UT (07:33:59.542).
The burst light curve shows a single pulse with a duration of ~6 s.
As observed by Konus-Wind the burst
had a fluence of 4.90(-2.76, +0.26)x10^-6 erg/cm2,
and a 64-ms peak flux measured from T0-0.016 s
of 4.44(-2.65, +0.91)x10^-6 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) is well fitted
(in the 20 keV - 1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 1.36(-0.25, +0.21)
and Ep = 211(-48, +95) keV (chi2 = 58.9/60 dof).
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB070917_T27239/
- GCN Circular #6799
A. Pelangeon & J-L. Atteia (LATT-OMP) report:
We have used the spectral parameters of the most intense
part of GRB 070917 provided by Golenetskii et al. (GCNC 6798)
to compute the spectral pseudo-redshift(**) of this burst
detected by SWIFT-BAT (Cummings et al., GCNC 6791).
We find a pseudo-redshift pz= 2.40 +/- 1.20
(**) cf. http://www.ast.obs-mip.fr/grb/pz
- GCN Circular #6800
S. B. Cenko (Caltech) reports on behalf of a larger collaboration:
We have imaged the field of GRB070917 (Cummings et al., GCN 6791) with the
automated Palomar 60-inch telescope. Images were obtained in the Kron R
and Sloan i' filters beginning 2.65 minutes after the burst trigger under
poor seeing conditions.
Inside the XRT error circle (Evans et al., GCN 6796), we marginally detect
in both filters a single faint source not clearly visible in the DSS-II
plate at the location (J2000.0)
RA: 19:35:40.53
Dec: +02:24:40.4
Using several nearby stars from the USNO-B catalog for reference, and the
empirical filter transformations from Jordi, Grebel, and Ammon (A&A 460,
2006), we measure magnitudes of R ~ 22.0 mag, i' ~ 21.6 mag, with the
large uncertainties (~ 0.4 mag) due to both photometric calibration and
the faintness of object.
Given the faintness, we cannot determine at this time if this object is
variable. Furthermore, as it likely lies below the detection limit of the
DSS-II survey, further observations are required to establish if it is
indeed the optical afterglow of GRB 070917.
- GCN Circular #6801
K. Antonyuk, V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the error box of GRB070917 (Cummings et al., GCN 6743) with
AZT-11 telescope of CrAO on Sep. 17. Series of images were obtained between
(UT) 2007-09-17 18:58:08 and 19:25:37 in R filter. In a combined image of
6x300 s within the XRT error circle (Evans et al., GCN 6796) we do not
detect any new sources in comparison with DSS2 up to the limiting magnitude
(3 sigma) R=21.1. Photometry calibration is performed against USNO-A2.0. The
combined image can be found in
http://grb.rssi.ru/GRB070917/GRB070917_AZT-11.gif
This message may be cited.
- GCN Circular #6803
J.P.U. Fynbo, M.D. Stritzinger, C. Gall (DARK/NBI), A.O. Jaunsen (Univ.
Oslo), C.C. Thoene, D. Malesani, P. Vreeswijk, J. Hjorth (DARK/NBI), J.
Sollerman (DARK and Univ. Stockholm) report on behalf of a larger
collaboration.
We observed the optical afterglow of GRB 070917 (Cummings et al., GCN
6791; Cenko, GCN 6800) with the Nordic Optical Telescope. Observations
started on 2007 Sep. 17.89 UT (14 hr after the GRB) in the V, R and I
bands. We detect the candidate optical afterglow reported by Cenko (GCN
6800) in all three bands. Assuming R=18.1 for the star USNO0900_15777166
we derive an R-band magnitude of 23.1. Compared to the magnitudes reported
by Cenko (GCN 6800) the source appears to be fading and we hence confirm
this source as the likely optical afterglow of GRB 070917.
- GCN Circular #6813
K.L. Page (U. Leicester) and J.R. Cummings (NASA/UMBC) report on behalf of
the Swift-XRT team:
Additional Swift-XRT observations have been performed of the possible
X-ray afterglow of GRB 070917 (Evans et al., GCN Circ. 6796). Between
~3.5e4 and 3.5e5 seconds after the burst, the source has faded following a
power-law decay slope of alpha = 1.1 +/- 0.3, confirming that it is,
indeed, the afterglow. Using ~14 ks of data, we find a refined position of
RA, Dec = 293.91897, 2.41104 degrees, which is equivalent to:
RA(J2000) = 19 35 40.55
Dec(J2000)= +02 24 39.8
with an estimated uncertainty of 6.0 arcsec (radius, 90% containment
including boresight uncertainty). This source is 0.7" from the optical
counterpart discussed by Cenko (GCN Circ. 6800) and Fynbo et al. (GCN Circ
6803).
This circular is an official product of the Swift-XRT team.
- GCN Circular #6817
GRB 070917: Suzaku WAM observation of the prompt emission
A. Endo, M. Tashiro, Y. Urata, K. Onda, M. Suzuki, N. Kodaka,
K. Morigami (Saitama U.), Y. Terada, T. Tamagawa (RIKEN),
M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira (Hiroshima U.),
K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.),
T. Enoto, R. Miyawaki, K. Nakawaza, K. Makishima (Univ. of Tokyo),
E. Sonoda, M.Yamauchi, S. Maeno, H. Tanaka, R. Hara (Univ. of
Miyazaki),
M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
The long GRB 070917 (Swift/BAT trigger #291292 ; Cummings et al.,
GCN 6791) triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV
at 2007-09-17 07:33:56.500 UT (=T0).
The observed light curve shows a single peak starting at T0+0s, ending
at T0+3s with a duration (T90) of about 2.5 seconds. The fluence in
100 - 1000 keV was 2.4 (+0.2, -0.2) * 10^(-6) erg/cm2. The 1-s peak flux
measured from T0+0s was 3.1 (+0.3, -0.3) photons/cm2/s in the
same energy range.
Preliminary result shows that the time-averaged spectrum from T0+0s to
T0+3s is well fitted by a single power-law with a photon index
of 1.6 (+0.2, -0.2) (chi2/d.o.f. = 9.6/11).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
- GCN Report 85.1
GCN_Report 85.1 has been posted:
http://gcn.gsfc.nasa.gov/reports/report_85_1.pdf
by J.R. Cummings
at CRESST/GSFC
titled: "Swift Observations of 070917"
Previous IAU Circulars 
