- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:40:24 UT
NOTICE_TYPE: Swift-BAT GRB Position
TRIGGER_NUM: 163170, Seg_Num: 0
GRB_RA: 345.440d {+23h 01m 46s} (J2000),
345.508d {+23h 02m 02s} (current),
344.856d {+22h 59m 25s} (1950)
GRB_DEC: +38.672d {+38d 40' 20"} (J2000),
+38.704d {+38d 42' 13"} (current),
+38.403d {+38d 24' 11"} (1950)
GRB_ERROR: 4.00 [arcmin radius, statistical only]
GRB_INTEN: 21178 [cnts] Image_Peak=527 [image_cnts]
TRIGGER_DUR: 4.096 [sec]
TRIGGER_INDEX: 289 E_range: 15-50 keV
BKG_INTEN: 184997 [cnts]
BKG_TIME: 31120.00 SOD {08:38:40.00} UT
BKG_DUR: 40 [sec]
GRB_DATE: 13683 TJD; 313 DOY; 05/11/09
GRB_TIME: 31179.37 SOD {08:39:39.37} UT
GRB_PHI: 98.59 [deg]
GRB_THETA: 11.83 [deg]
SOLN_STATUS: 0x3
RATE_SIGNIF: 15.06 [sigma]
IMAGE_SIGNIF: 9.84 [sigma]
MERIT_PARAMS: +1 +0 +0 +3 +1 +5 +0 +0 +56 +1
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 30"}
SUN_DIST: 124.45 [deg]
MOON_POSTN: 324.57d {+21h 38m 17s} -18.47d {-18d 28' 28"}
MOON_DIST: 60.45 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.53,-19.38 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 5.18, 40.65 [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.
- red DSS finding chart
ps-file
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:41:14 UT
NOTICE_TYPE: Swift-XRT Nack-Position
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.419d {+23h 01m 40s} (J2000)
POINT_DEC: +38.673d {+38d 40' 25"} (J2000)
IMG_START_DATE: 13683 TJD; 313 DOY; 05/11/09
IMG_START_TIME: 31265.59 SOD {08:41:05.59} UT, 86.2 [sec] since BAT Trigger Time
COUNTS: 25 Min_needed= 20
STD_DEV: 0.00 Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER: 4 Max_iter_allowed= 4
ERROR_CODE: 2
COMMENTS: SWIFT-XRT Nack Position.
COMMENTS: Algorithm did not converge; too many interations.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:43:19 UT
NOTICE_TYPE: Swift-BAT GRB Lightcurve
TRIGGER_NUM: 163170, Seg_Num: 0
GRB_RA: 345.440d {+23h 01m 46s} (J2000),
345.508d {+23h 02m 02s} (current),
344.856d {+22h 59m 25s} (1950)
GRB_DEC: +38.672d {+38d 40' 20"} (J2000),
+38.704d {+38d 42' 13"} (current),
+38.403d {+38d 24' 11"} (1950)
GRB_DATE: 13683 TJD; 313 DOY; 05/11/09
GRB_TIME: 31179.37 SOD {08:39:39.37} UT
TRIGGER_INDEX: 289
GRB_PHI: 98.59 [deg]
GRB_THETA: 11.83 [deg]
DELTA_TIME: 0.00 [sec]
TRIGGER_DUR: 4.096 [sec]
LC_URL: sw00163170000msb.lc
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 30"}
SUN_DIST: 124.45 [deg]
MOON_POSTN: 324.57d {+21h 38m 17s} -18.47d {-18d 28' 28"}
MOON_DIST: 60.45 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.53,-19.38 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.18, 40.65 [deg] ecliptic lon,lat of the pointing direction
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.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:45:24 UT
NOTICE_TYPE: Swift-UVOT Source List
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.418d {+23h 01m 40s} (J2000)
POINT_DEC: +38.674d {+38d 40' 25"} (J2000)
POINT_ROLL: 275.502d
IMG_START_DATE: 13683 TJD; 313 DOY; 05/11/09
IMG_START_TIME: 31263.48 SOD {08:41:03.48} UT, 84.1 [sec] since BAT Trigger Time
FILTER: 3, V
BKG_MEAN: 1.251
N_STARS: 75
X_OFFSET: 476 [pixels]
Y_OFFSET: 555 [pixels]
X_MAX: 1435 [pixels]
Y_MAX: 1514 [pixels]
DET_THRESH: 9
PHOTO_THRESH: 4
SL_URL: sw00163170000msufc0084.fits
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 31"}
SUN_DIST: 124.44 [deg]
MOON_POSTN: 324.58d {+21h 38m 20s} -18.47d {-18d 28' 10"}
MOON_DIST: 60.44 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.51,-19.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.16, 40.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-UVOT Source List.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:46:10 UT
NOTICE_TYPE: Swift-UVOT Processed Source List
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.418d {+23h 01m 40s} (J2000)
POINT_DEC: +38.674d {+38d 40' 25"} (J2000)
POINT_ROLL: 275.502d
IMG_START_DATE: 13683 TJD; 313 DOY; 05/11/09
IMG_START_TIME: 31263.48 SOD {08:41:03.48} UT, 84.1 [sec] since BAT Trigger Time
FILTER: 3, V
BKG_MEAN: 1.251
N_STARS: 75
X_OFFSET: 476 [pixels]
Y_OFFSET: 555 [pixels]
X_MAX: 1435 [pixels]
Y_MAX: 1514 [pixels]
DET_THRESH: 9
PHOTO_THRESH: 4
SL_URL: sw00163170000msufc0084.fits
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 31"}
SUN_DIST: 124.44 [deg]
MOON_POSTN: 324.58d {+21h 38m 20s} -18.47d {-18d 28' 10"}
MOON_DIST: 60.44 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.51,-19.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.16, 40.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-UVOT Processed Source List.
COMMENTS: All 4 attachments are included.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:46:33 UT
NOTICE_TYPE: Swift-UVOT Image
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.418d {+23h 01m 40s} (J2000)
POINT_DEC: +38.674d {+38d 40' 25"} (J2000)
ROLL: 275.502d
IMG_START_DATE: 13683 TJD; 313 DOY; 05/11/09
IMG_START_TIME: 31263.48 SOD {08:41:03.48} UT, 84.1 [sec] since BAT Trigger Time
FILTER: 3, V
EXPOSURE_ID: 153218463
X_OFFSET: 795 [pixels]
Y_OFFSET: 874 [pixels]
WIDTH: 160 [pixels]
HEIGHT: 160 [pixels]
X_GRB_POS: 955
Y_GRB_POS: 1034
BINNING_INDEX: 1
IM_URL: sw00163170000msuni0084.fits
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 31"}
SUN_DIST: 124.44 [deg]
MOON_POSTN: 324.58d {+21h 38m 20s} -18.47d {-18d 28' 10"}
MOON_DIST: 60.44 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.51,-19.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.16, 40.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-UVOT Image.
COMMENTS: The GRB Position came from the Window Position in the Mode Command.
COMMENTS: The image has 2x2 binning (compression).
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:47:16 UT
NOTICE_TYPE: Swift-UVOT Processed Image
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.418d {+23h 01m 40s} (J2000)
POINT_DEC: +38.674d {+38d 40' 25"} (J2000)
ROLL: 275.502d
IMG_START_DATE: 13683 TJD; 313 DOY; 05/11/09
IMG_START_TIME: 31263.48 SOD {08:41:03.48} UT, 84.1 [sec] since BAT Trigger Time
FILTER: 3, V
EXPOSURE_ID: 153218463
X_OFFSET: 795 [pixels]
Y_OFFSET: 874 [pixels]
WIDTH: 160 [pixels]
HEIGHT: 160 [pixels]
X_GRB_POS: 955
Y_GRB_POS: 1034
BINNING_INDEX: 1
IM_URL: sw00163170000msuni0084.fits
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 31"}
SUN_DIST: 124.44 [deg]
MOON_POSTN: 324.58d {+21h 38m 20s} -18.47d {-18d 28' 10"}
MOON_DIST: 60.44 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.51,-19.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.16, 40.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-UVOT Processed Image.
COMMENTS: All 4 attachments are included.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 09 Nov 05 08:46:58 UT
NOTICE_TYPE: Swift-XRT Lightcurve
TRIGGER_NUM: 163170, Seg_Num: 0
POINT_RA: 345.416d {+23h 01m 40s} (J2000)
POINT_DEC: +38.674d {+38d 40' 28"} (J2000)
LC_START_DATE: 13683 TJD; 313 DOY; 05/11/09
LC_START_TIME: 31268.37 SOD {08:41:08.37} UT, 89.0 [sec] since BAT Trigger Time
LC_STOP_DATE: 13683 TJD; 313 DOY; 05/11/09
LC_STOP_TIME: 31517.66 SOD {08:45:17.66} UT
LC_LIVE_TIME: 245.58 [sec], 98.5%
DELTA_TIME: 86150.71 [sec]
N_BINS: 100
TERM_COND: 0
LC_URL: sw00163170000msx.lc
SUN_POSTN: 224.58d {+14h 58m 19s} -16.93d {-16d 55' 31"}
SUN_DIST: 124.44 [deg]
MOON_POSTN: 324.58d {+21h 38m 20s} -18.47d {-18d 28' 09"}
MOON_DIST: 60.44 [deg]
MOON_ILLUM: 53 [%]
GAL_COORDS: 100.51,-19.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 5.16, 40.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-XRT Lightcurve.
- GCN Circular #4222
G. Tagliaferri (INAF-OAB), S. Barthelmy (GSFC), D. Burrows (PSU),
S. Campana (INAF-OAB), M. Chester (PSU), N. Gehrels (GSFC),
T. Mineo (INAF-IASF PA), K. Page (U Leicester), D. Palmer (LANL),
T. Sakamoto (GSFC)
on behalf of the Swift team:
At 08:39:39 UT, Swift-BAT triggered and located GRB 051109B (trigger=163170).
The BAT on-board calculated location is RA,Dec 345.440d,+38.672d
{23h 01m 46s,+38d 40' 20"} (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 ~20 sec. The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger.
The S/C slewed immediately and the XRT began observations at 08:41:06 UT
(86 seconds after the BAT trigger) in auto state. The on-board detection
algorithm failed to find a centroid, although the lightcurve suggests
a faint source. More information will be available after the next Malindi pass.
UVOT began observing at 08:41:03 UT, 84 sec after the BAT trigger.
The on-board source detection algorithm reports an uncataloged source
at RA=345.46 {23h 01m 50.40s}, DEC=+38.66 {38d 39' 36.0"}, 76 arcsec
from the BAT position, with V magnitude 18.4 +/-0.1, in a 200 sec observation
covering the BAT error circle. V-band extinction in the direction
of the BAT position is A_V = 0.55.
- GCN Circular #4224
H. Mito, Y. Nakada(Tokyo Univ.), H. Nakanishi(NAOJ), F. Egusa,
S. Komugi(Tokyo Univ.), K. Huang(IANCU), Y. Urata(RIKEN)
on behalf of EAFON report:
"We have imaged entire error region of GRB051109B(Tagliaferri et
al. GCN 4222, Swift trigger=163170) using Kiso 1.05m Schmidt
telescope. After end of twilight, we have started B and R band
observations at 09:12:07 (UT). Comparison with DSS images and USNO-B
catalog, there is no new source brighter than B=20.9, R=20.2. There is
also no significant signals at the UVOT position reported by
Tagliaferri et al (GCN 4222).
==========================================
Delay time(min) Filter Limiting mag.(SN=3)
32.5 R 20.2
45.7 B 20.9
==========================================
This message may be cited."
- GCN Circular #4225
P.A.Milne, G.G.Williams (Steward Obs),
H.-S.Park (LLNL), S.A. Barthelmy (GSFC)
on behalf of the Super-LOTIS GRB team report:
The automated 0.6-m Super-LOTIS telescope began observations of the error
region of GRB051109B (Swift trigger 163170) at 08:40:35.3 UT, 56 seconds
after the burst. We obtained a series of images in the R filter.
The field was at high airmass (at least secz=2.36), with thin clouds.
The source reported by the SWIFT/UVOT (Tagliaferri et al., GCN4222)
is not apparent in the first 10 second image (limiting magnitude ~ 17.0),
nor in subsequent co-added images. Further analysis of the complete
observing sequence is on-going.
- GCN Circular #4226
S. Campana (INAF-OAB), T. Mineo (INAF-IASF PA),
P. Romano (INAF-OAB), G. Tagliaferri (INAF-OAB),
D.N. Burrows (PSU) report on behalf of the Swift/XRT team:
The Swift XRT began observing GRB 051109B (trigger #163170, Tagliaferri
et al., GCN 4222) at 08:41:06 UT, but was unable to obtain an on-board
centroid. Analysis of the initial ground-processed data finds a faint
and uncataloged source at coordinates:
RA(J2000) = 23 01 50.35
Dec(J2000) =+38 40 49.6
We estimate an uncertainty of 4 arcseconds (90% containment), including
corrections for the XRT boresight offset. This position lies 60
arcseconds from the BAT position and at 74 arcsec from the
UVOT position, respectively, reported in GCN 4222.
- GCN Circular #4231
GRB 051109B : Lulin Optical Observations
F.Y. Huang, K.Y. Huang, W.H. Ip (NCU), Y. Urata(RIKEN),
Y. Qiu (BAO), Y.Q. Lou (THCA) on behalf of EAFON report:
"The R and V band images of GRB 051109B (Tagliaferri et al. GCN 4222)
were taken by Lulin 1-m telescope. The observation are started at 1.51
hours after the burst. No new source was detected at Swift/UVOT
position (Tagliaferri et al. GCN 4222) and Swift/XRT (Campana et
al. 4226) error regions. Compare with USNOB1.0 stars, the limiting
magnitudes of our R and V band co-add images (300s x 3 for each band)
are estimated as 21.0 and 20.0, respectively.
This message may be cited."
- GCN Circular #4232
G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB),
P. Romano (INAF-OAB), T. Mineo (INAF-IASFPA),
D.N. Burrows (PSU) report on behalf of the Swift/XRT team:
We have analysed 4.3 ks of XRT observations of the afterglow of
GRB051109B (Tagliaferri et al., GCN 4222; Campana et al. GCN4226).
The X-ray light-curve from 100s after the burst up to about 10 ks
after the burst is quite flat and well represented by a single power
law with a decay index alpha=-0.55+/-0.08 (90% containment).
The spectrum can be modeled with a power-law with photon index
Gamma = 2.33+/-0.30 (90% containment). There is evidence for an
absorbing column higher than the Galactic value (1.3e21 cm^-2)
at a level of (3.1+/-1.2)e21 cm^-2.
At 200 s the 0.5-10 keV unabsorbed flux was 1.7e-10 erg cm^-2 s^-1.
At 10000 s the afterglow had faded to flux level of 2.0e-11 erg cm^-2 s^-1.
Assuming the current flat decay we predict a flux of ~5.6e-13 erg cm^-2 s^-1
at 1 d from the burst.
- GCN Circular #4233
M. De Pasquale (UCL-MSSL), G. Tagliaferri (INAF-Brera), A.J. Blustin
(UCL-MSSL), D. Hinshaw (GSFC-SPSYS), M. Carter (UCL-MSSL),
N. Gehrels (GSFC) on the behalf the UVOT/Swift Team:
The Swift UVOT began observing the field of GRB051109B at 08:41:03 UT,
84 seconds after the BAT Trigger (Tagliaferri et al, GCN 4222). No new
source with respect to USNO B1.0 is detected within the 4 arcsecond
radius XRT error circle (Campana et al., GCN 4226), either in the first
exposure or in the coadded V-band exposures down to the following 3
sigma magnitude upper limits:
Filter T_range (sec) Exp (sec) 3sigUL
V 84-284 200 18.9
V 84-8280 4956 20.8
The source previously reported in GCN 4222 was actually an artefact
of the onboard processing and was not a real source.
These values are not corrected for Galactic extinction.
- GCN Circular #4236
W. Rujopakarn (U Mich), E.S. Rykoff (U Mich), F. Yuan (U Mich) report on =
behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB =
051109B (Swift trigger 163170), producing images beginning 9.1 s after =
the GCN notice time. An automated response took the first image at =
08:40:29.1 UT, 50.7 s after the burst, under fair conditions. We took 10 =
5-sec, 10 20-sec and 50 60-sec exposures. These unfiltered images are =
calibrated relative to USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within the =
3-sigma error circle, for both single images and coadding into sets of =
10. We also note that we found no new object within the error circle of =
XRT position given by Campana et al. (GCN 4226). Individual images have =
limiting magnitudes ranging from 15.8-17.8; we set the following =
specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
08:40:29.1 08:40:34.1 5 16.8 49.8 N
08:40:29.1 08:41:51.1 82 18.0 49.8 Y
08:41:51.4 08:44:50.4 299 17.4 132.1 Y
- GCN Circular #4237
D. Hullinger (UMD), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hinshaw (GSFC-SPSYS), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
P. Meszaros (PSU), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-300 to T+300 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 051109B
(trigger #163170) (Tagliaferri, et al., GCN 4222).
The BAT ground-calculated position is
(RA,Dec) = 345.468, +38.666 {23h 1m 52.3s, 38d 39' 58"} [deg; J2000]
+-2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.
The light curve has a single peak. There is no strong emission in
the 100-350 keV band. T90 (15-350 keV) is (15 +- 1) sec
(estimated error including systematics).
The power law index of the time-averaged spectrum is 1.96 +- 0.25.
The fluence in the 15-150 keV band is (2.7 +- 0.4) x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T0+0.24 sec in the 15-150 keV
band is (0.5 +- 0.1) ph/cm2/sec. All the quoted errors are at the 90%
confidence level.
- GCN Circular #4241
K. Kinugasa (Gunma Astronomical Observatory) and K. Torii (Osaka U.) report:
The error region of GRB 051109b (Tagliaferri, et al. GCN 4222) was imaged
by the robotic 0.25m GETS telescope in the Gunma Astronomical Observatory.
Unfiltered imaging started at 08:52:45 UT (13.1 minutes after the trigger)
and 30 s integration was repeated.
We do not identify a new object within the BAT error region (Hullinger, et
al. GCN 4222) and the following 3-sigma upper limits are derived relative to
USNO-A1.0 R mag.
------------------------------------------
StartUT Limit Nframes
------------------------------------------
08:52:45 >18.7 20
09:06:33 >18.7 20
09:35:32 >18.4 30
------------------------------------------
- GCN Circular #4245
Dale A. Frail (NRAO), Alicia M. Soderberg (Caltech), and P. Brian
Cameron (Caltech) report on behalf of a larger collaboration:
"We observed the field of GRB 051109B (GCN 4222; GCN 4237) with the
Very Large Array at 8.5 GHz around November 11.15 UT. There is no
radio source at the XRT position (GCN 4226; GCN 4232), with a limit of
25 +- 23 uJy.
Within the +-2.0 arcmin BAT error radius GCN 4237) we find one radio
source at RA(J2000)=23 01 52.77, DEC(J2000) =+38 41 47.9, with
(conservative) astrometric errors of order 0.5 arcsec. This is likely
a background radio source, unrelated to the GRB. No 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 #4277
Atish P. Kamble (Raman Research Institute, Bangalore) and Kuntal Misra
(ARIES, Nainital) on behalf of a larger Indian GRB collaboration
We observed the field of GRB 051109B (GCN 4222; GCN 4237) with the
1m Sampurnanand Telescope at ARIES, Nainital in Rc band on November 09
between 18:53 UT and 19:13 UT.
There is no new source seen at the XRT position (GCN 4226; GCN 4232).
We put the upper limit of Rc > 21.5 at 0.4331 day after the GRB
using nearby USNO-B1.0 stars.
This message may be cited.
- GCN Circular #4296
K. Kinugasa (Gunma Astronomical Observatory) and K. Torii (Osaka U.) report:
The error region of GRB 051109B (Tagliaferri, et al. GCN 4222) was imaged
with the LN2 cooled CCD Camera atattched on the 150 cm telescope of the
Gunma Astronomical Observatory. Starting at 15:28 UT (6.8 hours after the
burst), V, Rc, and Ic frames were acquired.
We do not identify an optical counterpart for the X-ray afterglow (Campana,
et al. GCN 4226). Following 3-sigma upper limits are derived for the stacked
frames relative to USNO-B1.0 magnitudes.
---------------------------------
MidUT Filter Mag Exposure
---------------------------------
15:54 Rc >20.2 180s x 5
16:10 Ic >18.4 60s x 10
---------------------------------
- GCN Circular #5387
D. A. Perley, R. J. Foley, J. S. Bloom and N. R. Butler (UCB) report:
On the night of 2006 July 25 (UT), we imaged the field of GRB051109B
(GCN 4222) for 630 seconds in g' and 600 seconds in R using Keck I (+
LRIS). There is a bright (R ~ 14.5) spiral galaxy close to the XRT
position (GCN 4226), also visible in DSS and other surveys. In our
imaging, the galaxy is observed to be a barred spiral of type SBa. The
presence of a faint tidal bridge indicates that the galaxy has recently
interacted with a neighboring galaxy 60" to the north.
Using 25 X-ray sources and 51 DSS sources in the field, we calculate an
improved XRT position of RA = 23:01:50.21, dec = +38:40:46.0 (with a 90%
uncertainty radius of 2.2", including an estimate of the systematic
error.) This position lies inside an outer spiral arm of the galaxy,
identifying it as the GRB host. In addition, both our position and the
original XRT error circle include a faint optical point-like source at
RA = 23:01:50.30, dec = +38:40:46.7 (0.5" uncertainty).
We obtained spectroscopy of the host galaxy and optical source the
following night. The galaxy is observed to be at a redshift of z =
0.080, and lacks any strong emission features. Spectroscopy of the
point source inside the XRT error circle shows no evidence for a
nebular-phase supernova; however, there are emission lines indicating
active star formation in this region.
The offset of the position of the optical source to the galaxy center is
14.1", or 20.9 kpc at the observed redshift. This is the largest offset
yet seen in a long GRB in angular or physical scale. Using the 15-150
keV gamma-ray fluence (GCN 4237), E_iso for this GRB is 4.1 x 10^48
ergs, comparable to that observed for GRB980425 but less than that of
any other GRB. GRB980425/SN1998bw was also seen in a spiral galaxy at
large offset, and also lacked a detected optical afterglow.
Given the low redshift of this system, inspection of archival images for
the presence or absence of supernova emission is strongly encouraged.
We also encourage radio and X-ray observations to look for a late-time
afterglow or supernova.
Additional information on this GRB, including an image of the field, is
available at:
http://lyra.berkeley.edu/~dperley/051109b/host.html
- GCN Circular #5441
A. M. Soderberg (Caltech), D. A. Frail (NRAO) and P. Chandra (UVA/NRAO)
report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We re-observed the field of GRB 051109B (GCN 4222) centered on the
revised XRT position (GCN 5387) using the VLA on August 9.5 UT 2006 (t~9
months after the burst) at a frequency of 1.43 GHz. Comparison with our
previous VLA observations (GCN 4245) reveals no new sources within the
revised XRT error circle. We place a 3-sigma limit of 0.21 mJy.
Adopting a redshift of z=0.08 for the putative host galaxy (GCN 5387),
this limit corresponds to a radio luminosity 100 times fainter than that
observed for GRB 030329 at a comparable epoch (Frail et al. 2003, ApJ,
619, 944).
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
- astro-ph/0701855 from 30 Jan 2007
Troja: Swift Observations of GRB 051109B
We present Swift observations of GRB 051109B, a soft long burst triggered by
the Burst Alert Telescope (BAT). The soft photon index of the prompt emission
suggest it is a X-ray Flash (XRF) or, at least, a X-ray Rich (XRR) burst. The
X-ray lightcurve displays the canonical shape of many other GRBs, a double
broken power law with a small flare superimposed at ~T_0+1500 s, and its
extrapolation to early times smoothly joins with the BAT lightcurve. On the
basis of the derived optical to X-ray flux ratio, it cannot be classified as a
dark burst.
Previous IAU Circulars 