- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Tue 07 Jun 05 09:11:42 UT
NOTICE_TYPE: Swift-BAT GRB Position
TRIGGER_NUM: 132247, Seg_Num: 0
GRB_RA: 300.167d {+20h 00m 40s} (J2000),
300.232d {+20h 00m 56s} (current),
299.565d {+19h 58m 16s} (1950)
GRB_DEC: +9.137d {+09d 08' 13"} (J2000),
+9.152d {+09d 09' 08"} (current),
+8.998d {+08d 59' 54"} (1950)
GRB_ERROR: 4.00 [arcmin radius, statistical only]
GRB_INTEN: 5492 [cnts] Peak=271 [cnts/sec]
TRIGGER_DUR: 1.024 [sec]
TRIGGER_INDEX: 146 E_range: 25-100 keV
BKG_INTEN: 33117 [cnts]
BKG_TIME: 33064.00 SOD {09:11:04.00} UT
BKG_DUR: 8 [sec]
GRB_DATE: 13528 TJD; 158 DOY; 05/06/07
GRB_TIME: 33082.80 SOD {09:11:22.80} UT
GRB_PHI: 3.05 [deg]
GRB_THETA: 27.03 [deg]
SOLN_STATUS: 0x3
RATE_SIGNIF: 18.13 [sigma]
IMAGE_SIGNIF: 9.00 [sigma]
MERIT_PARAMS: +1 +0 +0 +1 +2 +5 +0 +0 +58 +1
SUN_POSTN: 75.58d {+05h 02m 20s} +22.78d {+22d 46' 35"}
SUN_DIST: 125.87 [deg]
MOON_POSTN: 80.91d {+05h 23m 38s} +27.65d {+27d 38' 44"}
MOON_DIST: 127.06 [deg]
MOON_ILLUM: 0 [%]
GAL_COORDS: 49.21,-10.89 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 304.57, 29.03 [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/SWIFT NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Tue 07 Jun 05 09:13:00 UT
NOTICE_TYPE: Swift-XRT Nack-Position
TRIGGER_NUM: 132247, Seg_Num: 0
POINT_RA: 300.154d {+20h 00m 37s} (J2000)
POINT_DEC: +9.118d {+09d 07' 06"} (J2000)
GRB_DATE: 13528 TJD; 158 DOY; 05/06/07
GRB_TIME: 33167.30 SOD {09:12:47.30} UT
COUNTS: 0 Min_needed= 20
STD_DEV: 0.00 Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER: 0 Max_iter_allowed= 4
ERROR_CODE: 1
COMMENTS: SWIFT-XRT Nack Position.
COMMENTS: No source found in the image.
- GCN/SWIFT NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Tue 07 Jun 05 09:17:15 UT
NOTICE_TYPE: Swift-XRT Lightcurve
TRIGGER_NUM: 132247, Seg_Num: 0
POINT_RA: 300.152d {+20h 00m 37s} (J2000)
POINT_DEC: +9.120d {+09d 07' 13"} (J2000)
LC_START_DATE: 13528 TJD; 158 DOY; 05/06/07
LC_START_TIME: 33174.24 SOD {09:12:54.24} UT
LC_STOP_DATE: 13528 TJD; 158 DOY; 05/06/07
LC_STOP_TIME: 33424.87 SOD {09:17:04.87} UT
LC_LIVE_TIME: 247.02 [sec], 98.6%
DELTA_TIME: 86149.37 [sec]
N_BINS: 100
TERM_COND: 0
LC_URL: sw00132247000msx.lc
SUN_POSTN: 75.58d {+05h 02m 20s} +22.78d {+22d 46' 35"}
SUN_DIST: 125.90 [deg]
MOON_POSTN: 80.92d {+05h 23m 41s} +27.65d {+27d 38' 49"}
MOON_DIST: 127.10 [deg]
MOON_ILLUM: 0 [%]
GAL_COORDS: 49.19,-10.89 [deg] galactic lon,lat of the pointing direction
ECL_COORDS: 304.55, 29.01 [deg] ecliptic lon,lat of the pointing direction
COMMENTS: SWIFT-XRT Lightcurve.
- GCN notice #3523
V. Testa, D. Fugazza, S. Covino, S. Campana, E. Molinari, F.M. Zerbi, G.
Chincarini, M. Rodono', G. Tosti, L.A. Antonelli, P. Conconi, G.
Cutispoto, L. Nicastro, E. Palazzi, F. Vitali, E. Meurs, P. Goldoni, on
behalf of the REM/ROSS Team
We imaged the field of GRB050607 with the robotic 60-cm REM telescope
located at La Silla, Chile. Observations were performed in fully
automated mode simultaneously in the near infrared and in the optical,
starting approximately 47 seconds after the alert. REM is equipped with
the REMIR near infrared camera (10x10 sq arcmin FoV, JHK filters) and
the ROSS optical spectrograph/imager (10x10 sq arcmin FoV, VRI filters
and AMICI prism). Observations were performed under good seeing
conditions.
A quick-look analysis does not reveal any new bright object in H band
down to approximately the 15th magnitude.
This message may be cited.
- GCN notice #3524
D.B. Fox and S.B. Cenko report on behalf of the Caltech-NRAO-Carnegie
GRB collaboration:
"We have observed the BAT localization region for GRB050607 with the
Robotic P60 in a sequence of exposures beginning at 09:29 UT,
approximately 18 minutes after the burst.
Inspection of our initial R-band (epoch 09:29) and i-band (09:34 UT)
images reveals no bright new sources to the limit of the USNO-B1.0
catalog, R < 19 mag."
- GCN notice #3525
A. Retter, J. Racusin, J. Kennea, D. Burrows (PSU), D. Palmer (LANL),
K. McGowan (MSSL), J. Cummings (NRC/GSFC), S. Barthelmy, N. Gehrels
(GSFC)
on behalf of the Swift Team report:
At 09:11:23 UT the Swift-BAT triggered on GRB 050607 (trigger 132247).
The BAT refined ground position is RA, Dec 300.167, +9.137 (J2000)
{20h00m40s, +09d 08' 13"}. The burst had 3 peaks over 30 seconds, with a
T90 of 26.5 seconds from T+0 to T+26.5 seconds. Its spectrum is well fit
by a simple power law with an index of 1.93 +/- 0.14. The total fluence
was (8.9 +/- 1.2) x 10^-7 erg/cm2 over 15-350 keV. The peak flux was
1.15+/-0.16 photons/cm2/s from T+1 to T+2 seconds. The burst was 27
degrees off the BAT boresight in the 87% coded field of view. Swift slewed
to the position of the burst immediately, starting 17 seconds after the
burst trigger.
The XRT was pointed promptly at the burst at 09:13:02 UT (100 s after the
BAT burst trigger). The XRT did not centroid on-board, but ground
analysis revealed a bright X-ray source near the center of the field of
view, with position RA(J2000) = 20h 00m 42.5s Dec(J2000) = +09d 08' 30''
We estimate an uncertainty of approximately 8 arcseconds radius (90%
containment). This position is 40 arcseconds from the BAT position.
Immediate data from UVOT will not be available due to the instrument
being in an engineering mode.
- GCN notice #3526
M.Cwiok, K.Krupska, K.Kwiecinska, L.Mankiewicz, M.Molak,
K.Nawrocki, L.W.Piotrowski, M.Sokolowski, J.Uzycki, G.Wrochna,
on behalf of "Pi of the Sky" collaboration
http://grb.fuw.edu.pl
"Pi of the Sky" apparatus has moved to the Swift-BAT trigger 132247
and it has taken series of 10s exposures starting 60s after the GRB
(40s after the alert). No new object has been found within
the Swift-BAT error box. The limiting magnitude is 11.5m (unfiltered)
for single exposures and 12.5m for the sum of 10 images. However,
the GRB counterpart might be hidden in the glow of 10.2m star
GSC 01071-00926 (BD +8 4298), which is within the error box.
- GCN notice #3527
James Rhoads reports on behalf of a larger collaboration:
I observed the field of GRB 050607 with the 4m Mayall Telescope
at Kitt Peak, starting on 2005 June 7 UT 09:20:46.
Observations continued until morning twilight at 11:18 UT.
We detect a faint, fading optical source located at
20:00:42.79 +09:08:31.5 (J2000), about 8 arcseconds
from the XRT source.
We calibrated astrometry to the nearby USNO star, located
at 20:00:42.70 9:08:35.0. Our *relative* astrometry
should be good to < 0.5".
The approximate I band magnitude is 22.65 (statistical error
is 0.1 mag, systematic error is 0.2-0.3 mags) in our first
exposure, which was 150 seconds commencing 563 seconds
after the burst.
Further analysis of the multiwavelength data set is in progress.
- GCN notice #3528
C.Pagani, D. Grupe, D. Burrows, J. Kennea, J. Racusin (PSU), and N Gehrels
(GSFC), on behalf of the Swift XRT team report:
We analyzed the XRT data of the first two orbits of GRB 050607
(Retter et al., GCN #3525). The observations started at 09:13:02 UT
(100 s after the BAT burst trigger). Preliminary analysis of the data
obtained in the first 4.2ks of observations gives the following refined
coordinates for the X-ray afterglow:
Ra-2000: 20h 00m 42.6s
Dec-2000: 09d 08' 26.9"
The centroiding error is 6" radius (90%containment).
This position is about 5" from the optical afterglow position reported by
Rhoads (GCN #3527) and 3" from the previously reported XRT position (Retter
et al., GCN #3525).
The X-ray spectrum can be fitted with a single powerlaw with an X-ray
photon index=1.86+/-0.44. The fit is consistent with Galactic absorption
(NH=1.41e21 cm-2).
The lightcurve has a peak around 310sec after the burst trigger.
The source had a unabsorbed flux of 1.6e-12 ergs/s/cm2 at approximately one
hour after the burst and is decaying with a decay slope alpha=0.58+/-0.12.
This message may be cited.
- GCN notice #3529
Y.Tokunaga,S.maeno,E.sonoda,M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the error circle of
GRB 050607 (GCN3525 ; Swift BAT Trigger time is 09:11:23 UT)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 14:54:24 UT on June.07.
We have compared with the USNO A2.0 catalog.
Preliminary analysis shows there is no new source brighter than
16.5 mag at the position reported by J.Rhoads et al.(GCN 3527)"
- GCN notice #3530
J. P. Halpern (Columbia), J. Kemp (Joint Astronomy Centre and Columbia),
and N. Mirabal (U. Michigan), report on behalf of the MDM Observatory
GRB follow-up team:
We monitored the location of Swift GRB 050607 and its decaying X-ray
afterglow (Retter et al., GCN #3525; Pagani et al., GCN #3528) in the
R band with the MDM 2.4m telescope beginning 16 minutes after the
trigger, and extending to 2 hours. Seeing was approximately 1.1".
The afterglow candidate discovered by Rhoads (GCN #3527) is present
in all of our images with 22.5 < R < 23, and appears to have faded.
However, it is difficult for us to characterize its variability at
this stage in the analysis as there may also be extended emission.
If correct, this is the faintest optical afterglow detected at the
equivalent time (Berger et al., astro-ph/0502468), even taking into
account the 0.4 magnitudes of R-band Galactic absorption in this
direction.
Images are posted at
http://www.astro.columbia.edu/~jules/grb/050607/
- GCN notice #3531
James Rhoads reports on behalf of a larger collaboration:
We have measured the flux of the GRB 050607 optical
afterglow (Rhoads 2005, GCNC 3527) in our five I band images
from t=640 to t=6330 seconds post-burst.
A power law decay with slope -0.5 gives a marginally acceptable
fit to the I band light curve. A better fit can be obtained by
a two-part power law, with an initial steep decay (exponent near
-1) up to t ~ 1700 seconds, followed by a flatter decay (exponent
near -0.3) from 1700 to 6300 seconds.
The overall optical decay slope is in good agreement
with the X-ray slope reported by Pagani et al (GCNC 3528).
We also obtained images of Landolt standard field SA 113.
We found a zero point error in our earlier photometry (GCNC 3527).
Our new zero point based on our standard star observations
gives a brighter afterglow magnitude at t=640 seconds:
I = 21.46 +- 0.1 (statistical) +- 0.3 (systematic)
The remaining systematic error will go away with a more
careful reduction. As a consistency check we find magnitude
I=16.2 for the star USNO 0975-17511046 (our astrometric
reference at 20:00:42.703 +9:08:34.98), which has USNO
tabulated magnitude Rmag=16.6 and B-R=0.7.
In addition to our I band data, we also monitored the burst
in B band and took smaller amounts of data in R, z, and g.
All data discussed here were obtained with the Mosaic 1 camera on
the 4m Mayall Telescope of the Kitt Peak National Observatory.
Observations started at 2005 June 7 UT 09:20:46, and continued
until 11:18 UT.
The transient is faint in the B filter. Our first B band epoch,
of 150 seconds centered at t=1384 seconds, does not show the afterglow
clearly. A formal aperture flux measurement at the transient location
yields flux 0.7 +- 0.25 microJansky, or B ~ 24.4 +- 0.4. This gives
an estimated spectral power law slope of f_nu ~ nu^-1.5 or steeper,
where we have accounted for the Galactic reddening based on the Schlegel
et al prediction (A_V = 0.6 mag, E(B-I) = 0.44 mag).
The faint B image is thus suggestive of a Lyman break in the spectrum,
though we cannot rule out a red power law with our present analysis.
We detect the transient at R band, placing a rough redshift bound z<5,
We do not detect it in our less sensitive z band images (suggesting
that the power law slope is not extremely red).
An I band finding chart and light curve are now available at
http://www.stsci.edu/~rhoads/GRB050607/
- GCN notice #3533
W. Li, R. Chornock, S. Jha, and A. V. Filippenko, University of
California, Berkeley, report:
"The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT)
at Lick Observatory observed GRB050607 detected with Swift
(Retter et al., GCN 3525). A series of images was automatically
obtained from 09:12:12 UT (49s after the burst) to 10:10:19 UT
(3536s after the burst) The sequence includes a combination of
images taken with the V and I filters, as well as some that are
unfiltered. We did not detect the optical afterglow as reported
by Rhoads (GCN 3527, 3531) and Halpern et al. (GCN 3530). Our
first 15s unfiltered image started at 49s after the burst has a
limiting magnitude of about 18.4 when compared to the USNO-B1.0
catalog, while a combined unfiltered image centered at 09:16:13 UT
(290s after the burst) has a limiting mag of about 19.6. "
This message may be cited.
- GCN notice #3534
J. Wren, W. T. Vestrand, P. Wozniak, R. White, S. Evans report on
behalf of the RAPTOR team at Los Alamos National Laboratory:
The RAPTOR-S telescope responded robotically to GRB 050607 (Swift
trigger 132247, GCN #3525). The first exposure began at 09:11:49.97 UT,
27.17 seconds after the trigger time and during the third peak
in the 15-350 keV light curve of the GRB. Observations continued
through morning twilight which began approximately 90 minutes later.
Vibrations due to high winds degraded the quality of several of the
response images. We do not detect the optical counterpart reported
by Rhoads (GCN #3527).
We are able to place the following limits on the early optical
afterglow based on calibration to the USNO-A2.0 R-band (times are
seconds since trigger):
mag | mid-exposure | start | end | exposure
limit | time | time | time | duration
---------------------------------------------------------------------
15.6 | 32.17 | 27.17 | 37.17 | 10
17.8 | 42.79 | 47.79 | 57.79 | 10
18.5 | 108.66 | 47.79 | 220.46 | 70 (sum of 7 10s images)
18.0 | 248.94 | 233.94 | 263.94 | 30
18.9 | 390.27 | 233.94 | 627.29 | 180 (sum of 6 30s images)
18.2 | 741.18 | 711.18 | 771.18 | 60
19.2 | 1303.89 | 711.18 | 1615.55 | 360 (sum of 6 60s images)
- GCN notice #3535
M. Nysewander, D. Reichart, J. A. Crain, A. Foster, M. Bayliss report on
behalf of the UNC team of the FUN GRB Collaboration:
We observed the BAT localization of GRB 050607 (Retter et al., GCN 3525)
with PROMPT beginning 13m 30s after the burst.
We do not detect a source within the refined XRT localization (Pagani et
al., GCN 3528) nor the source identified by Rhoads (GCN 3527).
3-sigma limiting magnitudes are based on 10 USNO-B1.0 stars for Rc and Ic
observations and 10 NOMAD stars for V observations. Initial limiting
magnitudes are poor due to a camera cooling error:
Mean Time Integration Filter Limiting Telescope
Since GRB Time Magnitude
14m 08s 1 x 77.5s Ic 17.5 PROMPT-5
17m 43s 2 x 77.5s V 18.4 PROMPT-5
21m 16m 1 x 77.5s Rc 19.7 PROMPT-5
24m 06s 1 x 77.5s Ic 19.2 PROMPT-5
26m 21s 2 x 77.5s V 19.5 PROMPT-5
29m 51s 3 x 76.25s Rc 20.5 PROMPT-5
36m 17s 4 x 76.25s Ic 20.2 PROMPT-5
41m 48s 3 x 76.25s V 19.4 PROMPT-5
47m 17s 2 x 76.25s Rc 20.3 PROMPT-5
51m 25s 1 x 76.25s Ic 19.4 PROMPT-5
Stacking all images yields 3-sigma limiting magnitudes of Ic > 20.5, Rc >
21.2, and V > 19.8.
PROMPT is still being built and commissioned.
- GCN notice #3536
GRB 050607 : Lulin R-band observation
C.W. Chen (NCU), K.Y. Huang, W.H. Ip (NCU), Y. Urata(RIKEN), Y. Qiu
(BAO), Y.Q. Lou (THCA) on behalf of EAFON report:
" We have imaged the entire error region of GRB 050607 (Retter et
al. GCN 3525) by using 1.0-m telescope at Lulin Observatory,
Taiwan. The R band observations started at 16.14 UT ( about 6.95 hours
after the burst). No source was detected at the X-ray afterglow
position ( Pagani et al. GCN 3528). The limiting magnitude of our R
band co-added image ( 300sec x 8) is 21.1 by comparing with USNOB1.0
stars.
This message may be cited."
- GCN notice #3537
Ivanushkina, M., Retter, A. (PSU), McGowan, K., Blustin, A.
(MSSL), Gehrels, N. (NASA/GSFC) on behalf of the Swift
UVOT team
The Swift Ultra-Violet/Optical Telescope (UVOT) began
observations of GRB050607 on June 7, 2005 at 22:36:23 UT,
~12 hours and 25 minutes after the initial Swift BAT trigger
(Retter et al., GCN 3525) as an uploaded ToO. Immediate data
from UVOT were not available due to the instrument being in
an engineering mode.
No optical counterpart is detected at the afterglow position
(Rhoads, GCN 3527) in summed images from any filter down to
the following 3-sigma upper limits:
Filter 3-sig UL Exposure (s) T_mid (s)
V 20.21 2036 51530
B 20.95 897 46942
U 20.18 771 42806
UVW1 20.95 900 41963
UVM2 21.33 1482 46727
UVW2 21.30 900 47844
Where T_mid is the mid-time of the summed exposure in seconds
after the BAT trigger.
The magnitudes are based on preliminary zero-points,
measured in orbit, and will require refinement with
further calibration.
- GCN notice #3538
V. Testa, E. Palazzi, P. D'Avanzo, L.A. Antonelli, E. Molinari, D. Fugazza,
S. Covino, S. Campana, F.M. Zerbi, G. Chincarini, M. Rodono', G. Tosti,
P. Conconi, G. Cutispoto, L. Nicastro, F. Vitali, E. Meurs, P. Goldoni,
on behalf of the REM/ROSS Team
We refined the analysis of the field of GRB050607 observed with the REM
telescope (GCN 3523) in fully automated mode simultaneously in the near
infrared and in the optical. Two R-band 3s exposures and five H-band 10s
exposures have been re-analyzed to search for new objects at the positions
reported by Rhoads (GCN 3527) and Pagani et al. (GCN 3528). We confirm
the non-detection reported in GCN 3523 and derived upper limits at 3 sigma
level (see the table below). The UT differences between optical and IR
acquisitions are due to different overheads and observing strategies adopted
by the two instruments.
Filter Instrument UT t_exp Time_from_burst Mag. Upper Limit
--------------------------------------------------------------------------
R ROSS 09:14:49 6s 207s 17.1
H REMIR 09:14:34 50s 192s 16.0
Observations were performed under moderate seeing conditions, the La Silla
DIMM giving an instantaneous value of 1.5 arcsec, and in photometric
conditions. Magnitudes have been calibrated with a set of stars around the
position of the optical detection (GCN 3527) extracted from the 2MASS catalog
for the H filter and from the USNO B1.0 catalog for the R filter.
This message may be cited.
- GCN notice #3539
R. Zhuchkov, I. Bikmaev, N. Sakhibullin (KSU/AST), R. Burenin,
M. Pavlinsky, R. Sunyaev (IKI), Z. Aslan, I. Khamitov (TUG),
U. Kiziloglu (METU), A. Alpar (Sabanci Uni.)
report:
We observed the error box of GRB 050607 (Retter et al., GCN 3525) with
Russian-Turkish 1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National
Observatory, Turkey). We made a set of 600s exposures in R and I,
starting at 21:00 UT, June 07, i.e. approximately 12 hours after the
burst. Observations were made under poor weather conditions (with 1.7''
seeing and cirruses).
We detect nothing at the position of the OT found by Rhoads et al. (GCN
3527, 3531). The upper limits are approximately I=22.6 and
R=23.7. Comparing to earlier measurements (Rhoads et al., GCN 3531) we
confirm that the source is fading.
This message may be cited.
- GCN notice #3540
James Rhoads reports on behalf of a larger collaboration:
We observed the afterglow of GRB 050607 with the 4m Mayall Telescope
of Kitt Peak National Observatory from UT 2005 June 8 10:33 to 11:05.
We obtained three I band exposures with total integration time
of 26 minutes. The GRB counterpart is weakly detected in the sum
of the three images, with a statistical error around 0.2 to 0.25
magnitudes.
Relative photometry with respect to a nearby field star
shows that the transient has faded by 2.3 +- 0.2 magnitudes
between t=640 seconds and t=92300 seconds post-trigger.
Based on a power law fit to the night 1 data (Rhoads, GCNC 3531),
with decay slope 0.5, we would expect a fading of 2.9 magnitudes
over the same period. This suggests that host galaxy light may
be contributing detectably to our most recent flux measurement.
However, the statistical significance of this excess is low.
A single power law fit to the combined night one and night two
data has a time decay slope of 0.4 and nearly acceptable residuals.
If we exclude the first point (t=640 seconds) from the fit, on the
supposition that the physics dominating the afterglow changed
around 1e3 seconds, the decay slope in our other UT 050607 data
becomes 0.3 and the UT 050608 point lies precisely on this shallow,
extrapolated decay.
Additional data would help distinguish among these possibilities,
and further monitoring is encouraged.
- GCN notice #3541
J. P. Halpern (Columbia), J. Kemp (Joint Astronomy Centre and Columbia),
and N. Mirabal (U. Michigan), report on behalf of the MDM Observatory
GRB follow-up team:
We reobserved the afterglow of GRB 050607 in the R band with the
MDM 2.4m telescope for 30 minutes starting on June 8 08:15 UT,
23 hr after the burst. Seeing was approximately 1.1", similar
to the previous night. An upper limit of R > 24.0 for a point
source is found at the position of the afterglow. The possible
host galaxy (Rhoads, GCN #3540) would be difficult to quantify
in our image due to the nearby bright star.
See http://www.astro.columbia.edu/~jules/grb/050607/
- GCN notice #3555
P. B. Cameron, and A. M. Soderberg (Caltech) report on behalf of the
Caltech-NRAO-Carnegie collaboration:
"We observed the field of GRB 050607 (GCN 3525) with the Very Large
Array at 8.5 GHz on June 8.21, 9.50 and 19.45 UT, and once at 4.9 GHz
on June 9.50 UT. No radio source is detected at the position of the
optical afterglow (GCN 3527) with 2-sigma limits of 50-80 microJy at
8.5 GHz and 90 microJy at 4.9 GHz."
- GCN notice #3855
A. Henden (AAVSO/USNO) reports on behalf of the USNO GRB Team:
We have acquired BVRcIc all-sky photometry for 23x23arcmin
fields centered on the coordinates of recent GRB localizations
with the USNOFS 1.0-m telescope on 1 or 2 photometric nights
but with bright moonlight and variable seeing. Stars brighter
than V=12.0 are saturated and should be used with care. We have
placed the photometric data on our anonymous ftp site:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb050525.dat
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb050607.dat
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb050802.dat
The astrometry in these files is based on linear plate solutions
with respect to UCAC2 or USNO-A2.0. The external errors are usually
200mas or better. The estimated external photometric error is
about 0.03mag. Some fields are relatively crowded, and the
large apertures required to handle the variable seeing also
blended some measurements, so choose comparison stars wisely.
We have one additional night for GRB050525 that will be
added when reductions are complete.
As always, you should check the dates on the .dat file prior to
final publication to get the latest photometry. There is
a README file on the ftp directory to give you information
about the procedures used to calibrate these fields.
- astro-ph/0603658 from 24 Mar 2006
Pagani: The Swift X-ray flaring afterglow of GRB 050607
The unique capability of the Swift satellite to perform a prompt and
autonomous slew to a newly detected Gamma-Ray Burst (GRB) has yielded the
discovery of interesting new properties of GRB X-ray afterglows, such as the
steep early lightcurve decay and the frequent presence of flares detected up to
a few hours after the GRB trigger. We present observations of GRB 050607, the
fourth case of a GRB discovered by Swift with flares superimposed on the
overall fading X-ray afterglow. The flares of GRB 050607 were not symmetric as
in previously reported cases, showing a very steep rise and a shallower decay,
similar to the Fast Rise, Exponential Decay that are frequently observed in the
gamma-ray prompt emission. The brighter flare had a flux increase by a factor
of approximately 25,peaking for 30 seconds at a count rate of approximately 30
counts s-1, and it presented hints of addition short time scale activity during
the decay phase. There is evidence of spectral evolution during the flares. In
particular, at the onset of the flares the observed emission was harder, with a
gradual softening as each flare decayed. The very short time scale and the
spectral variability during the flaring activity are indicators of possible
extended periods of energy emission by the GRB central engine. The flares were
followed by a phase of shallow decay, during which the forward shock was being
refreshed by a long-lived central engine or by shells of lower Lorentz factors,
and by a steepening after approximately 12 ks to a decay slope considered
typical of X-ray afterglows.
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