- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 10 Oct 07 20:46:01 UT
NOTICE_TYPE: Swift-BAT GRB Position
TRIGGER_NUM: 293795, Seg_Num: 0
GRB_RA: 150.530d {+10h 02m 07s} (J2000),
150.651d {+10h 02m 36s} (current),
149.746d {+09h 58m 59s} (1950)
GRB_DEC: +45.731d {+45d 43' 53"} (J2000),
+45.694d {+45d 41' 38"} (current),
+45.973d {+45d 58' 23"} (1950)
GRB_ERROR: 3.00 [arcmin radius, statistical only]
GRB_INTEN: 4427 [cnts] Image_Peak=599 [image_cnts]
TRIGGER_DUR: 0.512 [sec]
TRIGGER_INDEX: 124 E_range: 25-100 keV
BKG_INTEN: 31038 [cnts]
BKG_TIME: 74733.71 SOD {20:45:33.71} UT
BKG_DUR: 8 [sec]
GRB_DATE: 14383 TJD; 283 DOY; 07/10/10
GRB_TIME: 74747.98 SOD {20:45:47.98} UT
GRB_PHI: -10.85 [deg]
GRB_THETA: 29.04 [deg]
SOLN_STATUS: 0x3
RATE_SIGNIF: 52.96 [sigma]
IMAGE_SIGNIF: 19.16 [sigma]
MERIT_PARAMS: +1 +0 +0 +0 +2 +25 +0 +0 -40 +1
SUN_POSTN: 195.82d {+13h 03m 18s} -6.74d {-06d 44' 27"}
SUN_DIST: 66.11 [deg] Sun_angle= 3.0 [hr] (West of Sun)
MOON_POSTN: 191.11d {+12h 44m 26s} -8.16d {-08d 09' 36"}
MOON_DIST: 64.88 [deg]
MOON_ILLUM: 0 [%]
GAL_COORDS: 172.39, 51.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 135.37, 31.36 [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 = 193.10,17.43 [deg].
- red DSS finding chart
ps-file
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 10 Oct 07 20:49:27 UT
NOTICE_TYPE: Swift-BAT GRB Lightcurve
TRIGGER_NUM: 293795, Seg_Num: 0
GRB_RA: 150.530d {+10h 02m 07s} (J2000),
150.651d {+10h 02m 36s} (current),
149.746d {+09h 58m 59s} (1950)
GRB_DEC: +45.731d {+45d 43' 53"} (J2000),
+45.694d {+45d 41' 38"} (current),
+45.973d {+45d 58' 23"} (1950)
GRB_DATE: 14383 TJD; 283 DOY; 07/10/10
GRB_TIME: 74747.98 SOD {20:45:47.98} UT
TRIGGER_INDEX: 124
GRB_PHI: -10.85 [deg]
GRB_THETA: 29.04 [deg]
DELTA_TIME: 12.00 [sec]
TRIGGER_DUR: 0.512 [sec]
SOLN_STATUS: 0x3
RATE_SIGNIF: 52.96 [sigma]
IMAGE_SIGNIF: 19.16 [sigma]
LC_URL: sw00293795000msb.lc
SUN_POSTN: 195.83d {+13h 03m 18s} -6.74d {-06d 44' 30"}
SUN_DIST: 66.11 [deg] Sun_angle= 3.0 [hr] (West of Sun)
MOON_POSTN: 191.13d {+12h 44m 32s} -8.17d {-08d 10' 23"}
MOON_DIST: 64.90 [deg]
MOON_ILLUM: 0 [%]
GAL_COORDS: 172.39, 51.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 135.37, 31.36 [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 = 193.10,17.43 [deg].
- GCN Circular #6871
C. B. Markwardt (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
C. Pagani (PSU), P. Romano (Univ. Bicocca & INAF-OAB),
T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA) and
G. Stratta (ASDC) report on behalf of the Swift Team:
At 20:45:47 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 071010B (trigger=293795).
The BAT on-board calculated location is
RA, Dec 150.530, +45.731 which is
RA(J2000) = 10h 02m 07s
Dec(J2000) = +45d 43' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single FRED pulse
with a duration of about 20 sec. The peak count rate
was ~12,000 counts/sec (15-350 keV), at ~2 sec after the trigger.
Because Swift is in the process of returning to normal operations,
automatic slewing to GRBs is currently disabled outside of
business hours (US EDT). Therefore, there
are no prompt XRT or UVOT observations of this burst.
Burst Advocate for this burst is C. B. Markwardt (craigm 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 #6873
A. Oksanen (Nyrola Observatory, Jyvaskyla, Finland) reports to the AAVSO
International High Energy Network the following optical observations of
GRB071010B (GCN #6871, Markwardt et al.):
Arto Oksanen reports the detection of an optical transient located at
RA 10:02:9.26, Dec +45:43:50.3 (J2000) at an initial unfiltered magnitude of
17.538 calibrated relative to USNOB R-band magnitudes. Midpoint of the
exposures is 2007 Oct 10, 21:11:05 UTC, approximately 25 minutes after the
trigger.
There are no comparably bright stars within 0.5 arcminutes, and no minor
planets in the area.
Subsequent unfiltered images place the star fainter than 18th magnitude
(unfiltered) indicating the object has faded since observations began.
Analysis of additional unfiltered, Rc, Ic, and V images will be forthcoming.
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
- GCN Circular #6877
C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-119 to T+183 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 071010B (trigger #293795)
(Markwardt, et al., GCN Circ. 6871). The BAT ground-calculated position is
RA, Dec = 150.531, 45.733 deg which is
RA(J2000) = 10h 2m 7.5s
Dec(J2000) = 45d 44' 0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 84%.
The mask-weighted light curve shows a pretrigger pulse starting at ~T-45 sec,
peaking at ~T-20 sec, and returning almost to background at ~T-8 sec.
Then the main FRED pulse started at ~T-8 sec, peaked at ~T+2 sec, and
ends around T+60 sec. Swift slewed to a preplanned target at T+130 sec
at which point the burst location went out of the BAT FOV, so we have
no more data about activity on this burst after that time. A small third peak
starts at ~T+95 sec and is terminated by the spacecraft slew.
T90 (15-350 keV) is at least 35.7 +- 0.5 sec (estimated error
including systematics).
The time-averaged spectrum from T-35.7 to T+24.1 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.53 +- 0.22,
and Epeak of 52.0 +- 6.4 keV (chi squared 31.19 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 4.4 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+1.40 sec in the 15-150 keV band is
7.7 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 2.01 +- 0.05 (chi squared 46.71 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
- GCN Circular #6878
J. A. Kennea (PSU), V. Mangano (INAF/IASF) and C. Markwardt (GSFC/UMD)
report on behalf of the Swift/XRT team:
At 22:29:34 UT on Oct 10th, 2007, Swift/XRT began observing the field of
the BAT detected burst GRB071010B (Markwardt et al., GCN #6871). XRT took
807s of PC mode data, and detects an uncatalogued point source at the
following coordinates:
RA(J2000) = 10h 02m 09.2s,
Dec(J2000) = +45d 43m 52.2s,
with an estimated error of 5 arcseconds radius (90% confidence). This
position lies 20 arcseconds from the refined BAT position (GCN #6877), and
1.9 arcseconds from the tentative optical counterpart reported by Oksanen
et al. (GCN #6873).
Due to the short observation, we are unable to determine if this X-ray
source is fading.
- GCN NOTICE
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Thu 11 Oct 07 02:28:03 UT
NOTICE_TYPE: Swift-XRT Position
TRIGGER_NUM: 293795, Seg_Num: 0
GRB_RA: 150.5383d {+10h 02m 09.1s} (J2000),
150.6597d {+10h 02m 38.3s} (current),
149.7550d {+09h 59m 01.2s} (1950)
GRB_DEC: +45.7312d {+45d 43' 52.3"} (J2000),
+45.6935d {+45d 41' 36.5"} (current),
+45.9727d {+45d 58' 21.5"} (1950)
GRB_ERROR: 4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN: 1.00e-10 [erg/cm2/sec]
GRB_SIGNIF: 5.00 [sigma]
IMG_START_DATE: 14384 TJD; 284 DOY; 07/10/11
IMG_START_TIME: 80979.02 SOD {22:29:39.02} UT, 6232.0 [sec] since BAT Trigger Time
TAM[0-3]: 327.61 237.19 261.35 242.66
AMPLIFIER: 2
WAVEFORM: 134
SUN_POSTN: 196.04d {+13h 04m 10s} -6.83d {-06d 49' 50"}
SUN_DIST: 66.30 [deg] Sun_angle= 3.0 [hr] (West of Sun)
MOON_POSTN: 193.68d {+12h 54m 43s} -9.45d {-09d 26' 47"}
MOON_DIST: 67.27 [deg]
MOON_ILLUM: 0 [%]
GAL_COORDS: 172.39, 51.80 [deg] galactic lon,lat of the burst
ECL_COORDS: 135.38, 31.36 [deg] ecliptic lon,lat of the burst
COMMENTS: SWIFT-XRT Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
COMMENTS: TAM values are not valid.
- GCN Circular #6879
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 071010 (Swift-BAT trigger #293795:
Markwardt et al., GCN 6871, 6877) triggered
Konus-Wind at T0=74748.490 s UT (20:45:48.490).
The burst light curve shows a single pulse
with a duration of ~15 s, followed by a weak soft tail
seen up to T-T0 ~50 s.
There is a hint of the pretrigger pulse detected by BAT
(Markwardt et al., GCN 6877) in the Konus-Wind
soft energy band (18-70 keV).
As observed by Konus-Wind the burst
had a fluence of 4.78(-3.12, +0.95)x10^-6 erg/cm2,
and a 64-ms peak flux measured from T0+1.6 s
of 8.92(-5.99, +2.29)x10^-7 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+16.640 s) can be fitted
(in the 20 keV - 1 MeV range)
by GRBM (Band) model for which:
the low-energy photon index is alpha = -1.25 (-0.49, +0.74),
the high energy photon index beta = -2.65(-0.49, +0.29),
the peak energy Ep = 52 (-14, +10) keV (chi2 = 69.1/55 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/GRB071010_T74748/
- GCN Circular #6884
D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report:
We observed the field of GRB 071010B (Markwardt et al., GCN 6871) with the
TLS 1.34m Schmidt telescope under bad weather conditions (low
transparency, passing clouds). We obtained 9 600 second integrations in
the Rc Filter starting at UT 1:26:44 (0.2 days after the GRB). The
afterglow (Oksanen, GCN 6873) is clearly detected on several frames, the
others were lost to passing clouds.
We measure a refined OT position (J2000) in comparison to the USNO-B1.0
catalog:
RA = 10:02:09.24
Dec. = +45:43:49.7
with errors of 0".7.
This is in accordance with the position of Oksanen (GCN 6873) and the
Swift XRT detection (Kennea et al., GCN 6878).
Preliminary photometry on raw images yields a decaying afterglow. Assuming
the USNO-B1.0 star at RA = 10:02:06.71, Dec. = +45:42:34.2 (J2000) to have
R2 = 17.26, we find the following magnitudes:
Date Mid-Time Rc Rc error
11.06361 0.19848 18.61 0.07
11.07113 0.20600 18.73 0.05
11.07865 0.21352 18.87 0.06
11.13149 0.26637 19.21 0.05
Oksanen (GCN 6873) reported the OT to have R > 18 mag already in the first
hour, therefore our bright detections may indicate a slow decay or a
rebrightening. This GRB was a bright, soft FRED (Markwardt et al., GCN
6877; Golenetskii et al., GCN 6879) with a well determined peak energy.
This may indicate an event at relatively low redshift. Further photometric
and especially spectroscopic follow-up is encouraged.
This message may be cited.
- GCN Circular #6888
S. B. Cenko (Caltech), A. Cucchiara, D. B. Fox (Penn State), E. Berger
(Princeton), and P. A. Price (Hawaii) report on behalf of a larger
collaboration:
We have obtained a single 1800 s spectrum of the optical afterglow
(Oksanen; GCN 6873) of GRB071010B (Markwardt et al.; GCN 6871) with the
Gemini Multi-Object Spectrograph mounted on the Gemini North telescope.
Our exposure began at 14:41 UT on October 11, and covered the wavelength
range from 4000 - 8000 A.
We find a strong absorption doublet at ~ 5450 A that we identify as Mg II
2796 / 2803 at z = 0.947. Weaker absorption features corresponding to Mg
I 2852 and Fe II 2586 are also present at the same redshift. A
preliminary inspection reveals no other absorption nor emission systems
present.
If the z=0.947 system is the host redshift, we calculate an isotropic
energy release of ~ 1.1e52 erg in the 20 keV - 1 MeV observed frame
(Golenetskii et al., GCN 6879).
- GCN Circular #6890
Jason X. Prochaska (UCSC), D. A. Perley, M. Modjaz, J.S. Bloom,
D. Poznanski (UC Berkeley) report on behalf of GRAASP:
"We observed the afterglow of GRB 071010B with the Keck/LRIS
dual spectrometer for a series of 300s exposures starting
at UT 15:08 under good conditions. We confirm the report
of Cenko et al. (GCN 6888) of a strong MgII absorber at
z=0.947 in the afterglow spectrum. Our data show corresponding
FeII transitions at rest-frame wavelengths: 2344, 2382, 2586,
and 2600. We do not identify any FeII* transitions and also set
an upper limit to the rest equivalent width of ZnII 2026: EW<0.4A.
Such weak ZnII 2026 absorption is rare for GRB host galaxies,
but not unprecedented.
A more conservative upper limit to the GRB redshift
is set by the absence of IGM signatures at 3500A which
indicates z_GRB < 1.9.
Further analysis is in progress."
This GCN may be cited.
- GCN Circular #6892
A. Oksanen (Nyrola Observatory, Jyvaskyla, Finland), M. Templeton (AAVSO)
and A. Henden (AAVSO) report further details on optical observations of
GRB071010B (GCN #6871, Markwardt et al.; GCN #6873 Oksanen; GCN #6878
Kennea et al.; GCN #6884 Kann et al.):
Further to the initial report given in GCN #6873, Arto Oksanen reports
unfiltered photometry of the GRB 071010B afterglow spanning 2007 Oct 10
21:02:33 UT to 2007 Oct 11 03:24:27 UT (T0 + 17 minutes to T0 + 6 hours 39
minutes post-burst). The data are reasonably well fit by a single power
law with index -1.14. The measured unfiltered magnitudes are
approximately 0.3 magnitudes fainter than the Rc magnitudes reported by
Kann et al (GCN #6884) taken at the same time, which is consistent with
differences in zero-point calibration and bandpass. It should be noted
that this field is covered by the SDSS, and that the AAVSO will obtain a
BVRI calibration with the Sonoita Research Observatory, weather
permitting.
Oksanen also reports additional preliminary Ic and V-band magnitudes:
2007 Oct 10, 21:32 UT Ic = 17.64 +/- 0.05
2007 Oct 10, 21:52 UT V = 18.30 +/- 0.05
Both magnitudes are calibrated relative to the transformed SDSS ugriz
magnitudes for the object at RA 10:01:54.62, Dec +45:40:29.0 (J2000).
Further details of these observations, light curves, and analyses are in
preparation for publication in the electronic Journal of the AAVSO.
Full details of the observations are available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB071010B_2454384.45422_.txt
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
- GCN Circular #6893
A. C. Updike (Clemson), P. A. Milne (Steward Observatory), G. G. Williams
(MMTO), and D. H. Hartmann (Clemson) report on behalf
of the Super-LOTIS Collaboration:
The robotic 0.6m Super-LOTIS telescope observed the field of GRB 071010B
(GCN 6871, Markwardt et al.) beginning at 10:24 UT on Oct 11, 13.6 hours
after the trigger. We obtained 59 minutes in the R band
and 19 minutes in the V band. We do not detect the OT (Oksanen GCN
6873, Kann et al. GCN 6884) in the stacked exposures. Limiting
magnitudes were determined using 10 field stars calibrated to the USNO
B1.0 catalog.
t_start (UT) Filter exp (s) Limit
-------------------------------------------------------------
10:24:40 R 59x60 > 20.4
10:49:00 V 19x60 > 19.2
This message may be cited.
- GCN Circular #6897
M. Im, I. Lee (Seoul National University), and Y. Urata
(Saitama University) on behalf of the EAFON team:
Using the Mt. Lemmon (Arizona, US) 1.0m telescope
operated by the Korea Astronomy Space Science Institute,
we observed the field of GRB071010B (GCN 6871,
Markwardt et al.) beginning at 11:19:26 UT on Oct 11,
or 14.3 hrs after the trigger.
From a stacked image of four, 5 min frames in the R-band,
we detect the OT (Oksanen GCN 6873, Kann et al. GCN 6884)
with a high significance (S/N > 15) at the position
they reported. Compared to the non-detection
report at 13.6 hrs after the trigger (GCN 6893),
our detection suggests re-brightening of OT.
A preliminary photometry of the object using USNO B1.0
R2 mag of two stars near the OT is given below
(aperture mag with 6" diameter circle).
t_start (UT) Filter exp (sec) R-mag err
-----------------------------------------------------
11:19:26 R 4x300 19.8 0.08 (uncertain)
We will report later, a more careful analysis of the BVR
images taken during the same period.
- GCN Report 92.1
GCN_Report 92.1 has been posted:
http://gcn.gsfc.nasa.gov/reports/report_92_1.pdf
by C. Markwardt
at CRESST/UMD/NASA/GSFC
titled: "Swift Observations of GRB 071010B"
- GCN Circular #6903
M. Templeton (AAVSO), D.A. Kann (TLS Tautenburg), A. Oksanen (Hankasalmi
Observatory, Hankasalmi, Finland) and A. Henden (AAVSO) report the
following correction to the decay rate for unfiltered optical photometry
of GRB 071010B given in Oksanen et al. (GCN #6892):
Due to a software error, the decay rate originally given in GCN #6892
(-1.14) is incorrect. The correct power-law for the optical decay is
-0.482 +/- 0.064. This is consistent with an independent measure of
-0.464 +/- 0.016 performed by D.A. Kann using additional data from the
TLS Tautenburg 2-meter telescope.
We also note the original data were obtained by A. Oksanen with the
Hankasalmi Observatory 0.4-meter, rather than at Nyrola Observatory,
and have corrected his affiliation accordingly.
The corrected version of GCN #6892 follows:
A. Oksanen (Hankasalmi Observatory, Hankasalmi, Finland), M. Templeton
(AAVSO) and A. Henden (AAVSO) report further details on optical
observations of GRB071010B (GCN #6871, Markwardt et al.; GCN #6873
Oksanen; GCN #6878 Kennea et al.; GCN #6884 Kann et al.):
Further to the initial report given in GCN #6873, Arto Oksanen reports
unfiltered photometry of the GRB 071010B afterglow spanning 2007 Oct 10
21:02:33 UT to 2007 Oct 11 03:24:27 UT (T0 + 17 minutes to T0 + 6 hours
39 minutes post-burst). The data are reasonably well fit by a single
power law with index -0.482 +/- 0.064. The measured unfiltered
magnitudes are approximately 0.3 magnitudes fainter than the Rc
magnitudes reported by Kann et al (GCN #6884) taken at the same time,
which is consistent with differences in zero-point calibration and
bandpass. It should be noted that this field is covered by the SDSS,
and that the AAVSO will obtain a BVRI calibration with the Sonoita
Research Observatory, weather permitting.
Oksanen also reports additional preliminary Ic and V-band magnitudes:
2007 Oct 10, 21:32 UT Ic = 17.64 +/- 0.05
2007 Oct 10, 21:52 UT V = 18.30 +/- 0.05
Both magnitudes are calibrated relative to the transformed SDSS ugriz
magnitudes for the object at RA 10:01:54.62, Dec +45:40:29.0 (J2000).
Further details of these observations, light curves, and analyses are in
preparation for publication in the electronic Journal of the AAVSO.
Full details of the observations are available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB071010B_2454384.45422_.txt
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
- GCN Circular #6909
A. Henden (AAVSO) reports:
While the field of GRB071010B has been observed by SDSS, we have also
obtained a two-night BVRcIc field calibration using the 35cm robotic
telescope at Sonoita Research Observatory. The calibration file
has a limiting magnitude around V=18, with good standards brighter
than V=16 or so. The file is available at
ftp://ftp.aavso.org/public/calib/grb/grb071010b.dat
This calibration is based on numerous Landolt standards, and has
an external zeropoint error of about 0.02mag. We do not expect
at this time to extend this calibration to fainter magnitudes.
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
- GCN Circular #6915
P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the
Caltech-NRAO-Carnegie GRB Collaboration:
"We observed the Swift burst GRB 0701010B (GCN#6871) using the VLA at
a frequency of 8.46 GHz and starting at 18.42 UT on Oct 13, 2007.
We do not detect any radio emission at a position of (J2000):
RA: 10 02 09.28
Dec: 45 43 49.07
The flux density at this position is 276 +- 49 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
- GCN Circular #6916
P. Chandra (UVA/NRAO) reports:
There was a typo in the text of GCN#6915 sent by me. The GRB 071010B is
indeed detected in 8.46 GHz VLA radio band.
- GCN Circular #6918
D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report:
We observed the afterglow (Oksanen, GCN 6873) of GRB 071013 (Markwardt et
al., GCN 6871) with the Tautenburg 1.34m Schmidt telescope under good
conditions, obtaining 16 600 second images in the Rc band at 3.2 to 3.3
days after the GRB. The afterglow is clearly detected in all frames. Using
two USNO B1.0 stars (RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4,
R2=16.80; RA (J2000) = 10:02:23.11, Dec. (J2000) = +45:41:41.1, R2=16.94),
we revise our original photometry (Kann, Hoegner & Filgas, GCN 6884) using
fully reduced images:
Date Mid-Time Rc dRc
11.06361 0.19848 19.145 0.041
11.07113 0.20600 19.121 0.033
11.07865 0.21352 19.198 0.030
11.08617 0.22104 19.163 0.062
11.13149 0.26637 19.396 0.032
11.13902 0.27389 19.512 0.223 (Clouds)
Using the same comparison stars, we derive the following magnitudes from
our new images:
Date Mid-Time Rc dRc
14.05372 3.18859 20.800 0.139
14.06126 3.19613 20.815 0.142
14.06878 3.20365 20.779 0.092
14.07630 3.21117 20.852 0.088
14.08382 3.21869 20.921 0.095
14.09133 3.22621 20.899 0.097
14.09885 3.23372 20.888 0.088
14.10638 3.24125 20.839 0.079
14.11389 3.24877 20.967 0.090
14.12141 3.25628 20.946 0.078
14.12892 3.26380 21.014 0.093
14.13644 3.27131 20.929 0.075
14.14395 3.27882 20.814 0.071
14.15146 3.28634 20.732 0.066
14.15899 3.29386 20.792 0.069
14.16650 3.30138 20.864 0.076
We note that the last data points seem to indicate a small rebrightening
feature which was receding again when twilight stopped our observations.
With Rc ~ 20.9 at 3.2 days after the GRB, the afterglow is among the
brightest observed so far (Kann, Klose & Zeh 2006, ApJ, 641, 993; Kann et
al., in preparation). Using data from Arto Oksanen
(http://murtoinen.dyndns.org/ccd/grb/grb071010/) and Im, Lee & Urata (GCN
6897), we find that the afterglow can be fit with a broken power law with
pre-break slope alpha_1 = 0.3 +/- 0.083, post-break slope alpha_2 = 0.575
+/- 0.009, and break time t_b = 0.049 +/- 0.019 days. The very shallow
decay (Kann, Hoegner & Filgas, GCN 6884, Templeton et al., GCN 6903) is
thus seen to continue, which is highly unusual.
Further observations are planned and encouraged at other facitlities.
This message may be cited.
- GCN Circular #6919
D. Kocevski, D. A. Perley, J. S. Bloom, M. Modjaz, and D. Poznanski
(UC Berkeley)
report:
"In addition to the spectroscopic followup reported by Prochaska et
al. (GCN 6890), we acquired a 90s exposure in R band and a 30s
exposure in g and V bands of the field containing GRB 071010B with
the Keck I 10m telescope (+LRIS), beginning at 15:01:21 UT on
2007-10-11. The optical afterglow at 10:02:9.26, +45:43:50.3
reported by Oksanen et al. (GCN 6871) and confirmed by Kann et al.
(GCN 6884 ) was clearly detected. Using aperture photometry, we
estimate the multi-color magnitudes of the afterglow to be:
R = 19.62
V = 19.71
g = 19.10
when calibrated to Landolt standard star observations. We note that
the afterglow had not faded considerably from the magnitude reported
by Im et al. (GCN 6897) whose observations began approximately 4
hours earlier.
- GCN Circular #6920
M. Im, I. Lee (Seoul National University), and Y. Urata
(Saitama University) on behalf of the EAFON team:
Using the Mt. Lemmon (Arizona, US) 1.0m telescope
operated by the Korea Astronomy Space Science Institute,
we continued our observation of GRB071010B (GCN 6871,
Markwardt et al.), beginning at 11:37:19 UT on Oct 12,
or 1.62 days after the trigger.
From a stacked image of nine, 5 min frames in the R-band,
we detect the OT again (Oksanen GCN 6873, Kann et al. GCN 6884).
A preliminary photometry of the object using the standard
star data taken during the same day is given below
(aperture mag with 6" diameter circle). Also given is a
slightly revised R-band magnitude we reported earlier
(Im et al., GCN 6897).
t_start (UT) Filter exp (sec) R-mag err
-----------------------------------------------------
Oct. 11,
11:19:47 R 4x300 19.81 0.08
Oct. 12,
11:37:19 R 9x300 20.54 0.10
Our result is consistent with the recent report that
the GRB is fading rather slowly (GCN 6918, Kann et al.;
GCN 6919 Kocevski et al.). However, compared with
the magnitudes at Oct. 14 reported by Kann et al. (6918),
our photometry suggests a very marginal decrease in
the brightness between Oct. 12 - Oct. 14.
We will report later, the BVRI photometry data
taken during the same period.
This message may be cited.
- GCN Circular #6923
D. A. Kann, U. Laux & R. Filgas (TLS Tautenburg) report:
We observed the afterglow (Oksanen, GCN 6873) of GRB 071010B (Markwardt et
al., GCN 6871) with the Tautenburg 1.34m Schmidt telescope under mediocre
conditions (low transparency), obtaining 12 600 second images in the Rc
band at 5.3 days after the GRB. The afterglow is faintly detected in all
frames. We create a stacked image and, using the same comparison stars as
Kann, Hoegner & Filgas (GCN 6918), we derive the following magnitude:
Date Mid-Time Rc dRc
16.09041 5.22528 21.293 0.045
In comparison with earlier data (see Kann, Hoegner & Filgas, GCN 6918, for
references, and adding Kocevski et al., GCN 6919; Im, Lee & Urata, GCN
6920), we find the afterglow to be 0.3 magnitudes fainter than the
extrapolation of the earlier decay. This may indicate that a break has
occured.
Inclement weather and an instrument switch will probably not allow us to
obtain another epoch. Further follow-up at other northern facilities is
strongly encouraged to check the validity of the break.
This message may be cited.
- GCN Circular #6924
We observed the afterglow (Oksanen, GCN 6873) of GRB 071010B
(Markwardt et al., GCN 6871) with the EST 1m telescope at
Xinglong Observatory started from 19:07:59(UT) Oct.11. Totally
11*600s V-band images were obtained. With the calibration data
reported by Henden (GCN 6909) we derived the afterglow had
a magnitude V=20.75 +/- 0.05 with mid-time 23.314 hours
after the burst.
Compared with the V-band magnitude of Daniel Kocevski
(GCN 6919), we found the V-band magnitude of the afterglow
decayed deeply about 1 magnitude after about 5 hours.
This message may be cited.
- GCN Circular #6928
D. Stern (JPL), D. A. Perley (UC Berkeley), N. Reddy (NOAO), J. X.
Prochaska (UCSC), H. Spinrad (UCB) and M. Dickinson (NOAO) report:
On the night of 2007 Oct. 11 we observed the afterglow of GRB 071010B
(GCN 6871, Markwardt et al.; GCN 6873, Okansen et al.) with the Keck II
10m telescope + DEIMOS, for a total integration time of 1260 seconds,
starting at 14:41 UT. The wavelength coverage was between 5230 and
10480 Angstroms.
The detection of MgII previously reported by Cenko et al. (GCN 6888) and
Prochaska et al. (GCN 6890) at a redshift of 0.947 is further confirmed,
as is a weak detection of MgI 2852.
In addition, the [OII] 3727 doublet emission feature is well-detected at
the same redshift, superimposed on the continuum. [OIII] 5008 is also
detected, as is (marginally) [OIII] 4960.
These results strongly suggest that the redshift of GRB 071010B and its
host galaxy is most likely 0.947.
- GCN Circular #6931
C. Kira, M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.),
Y. Terada, T. Tamagawa (RIKEN), K. Yamaoka, Y. E. Nakagawa,
S. Sugita (Aoyama Gakuin U.), M. Tashiro, Y. Urata, A. Endo,
K. Onda, M. Suzuki, N. Kodaka, K. Morigami (Saitama U.),
T. Enoto, R. Miyawaki, K. Nakazawa, 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 071010B (Swift/BAT trigger #293795;
C. B. Markwardt et al., GCN 6871, 6877)
was triggered by the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 2007-10-10 20:45:49 UT (=T0).
The observed light curve shows a single FRED-like peak,
starting at T0-3s, ending at T0+10s, with a duration (T90) of about 5 seconds.
There is no signal corresponding to the pre-trigger pulse and the weak soft tail
detected by the Swift/BAT (GCN Report 92.1) and the Konus-Wind (GCN 6879)
in the WAM energy band (50-5000 keV).
The fluence in 100 - 1000 keV was (1.8 +/- 0.3)*10^-6 erg/cm^2.
The 1-s peak flux measured from T0+1s was 1.1 +/- 0.3 photons/cm^2/s in the same
energy range.
Preliminary result shows that the time-averaged spectrum from T0-3s to
T0+10s is well fitted by a single power-law with a photon index
of 3.2 (-0.5, +0.7) (chi^2/d.o.f = 6/8 ).
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 Circular #6935
D. A. Kann, U. Laux, R. Filgas (TLS Tautenburg), A. Oksanen (Hankasalmi
Observatory, Hankasalmi, Finland), S. Covino (Brera), V. D'Elia (Rome), V.
Lorenzi (INAF/TNG), and R. Decarli (Como) report:
At 7 days after the GRB, we obtained further Rc band imaging of the GRB
071010B (Markwardt et al., GCN 6871) afterglow (Oksanen, GCN 6873). We
obtained a single 600 second image with the Tautenburg 1.34m Schmidt
telescope under bad conditions (passing clouds, high humidity, wind). The
afterglow is only faintly detected. Furthermore, we obtained 5 x 180 sec
images with the TNG telescope in La Palma. The afterglow is clearly
detected in each image and there is no evidence for underlying extended
emission. Finally, at dawn, we obtained 4 x 100 sec Rc images with the
NOT.
Using the same comparison stars as Kann, Hoegner & Filgas (GCN 6918), we
derive the following magnitude:
Date Mid-Time Rc dRc Exposure Telescope
18.10966 7.24453 21.593 0.244 1 x 600 TLS
18.20581 7.34069 21.801 0.028 5 x 180 TNG
18.26479 7.39966 21.756 0.106 4 x 100 NOT
These values confirm the light curve break first reported by Kann, Laux &
Filgas (GCN 6923). Using all data available so far (see GCN 6918 and GCN
6923 for references), we find preliminary fit results for data after 0.05 days:
alpha_1 = 0.56 +/- 0.01, alpha_2 = 1.46 +/- 0.10, t_b = 3.44 +/- 0.39
days.
The post-break slope is still quite shallow, leaving open if this was a
jet break or not. We note that the first break at 0.049 days (GCN 6918)
has Delta alpha ~ 0.26 and therefore may be a cooling break.
This message may be cited.
- GCN Circular #6945
E. Klunko, A. Marchenkov, M. Eselevich (ISTP), A. Shulga, A. Volnova (SAI
MSU), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration
report:
We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884)
of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.12 ((UT)
19:44:42 - 20:45:06) and Oct. 13 ((UT)19:17:13 - 20:14:49) with 1.5m
telescope of Sayan observatory. The optical afterglow is clearly visible in
stacked images of both epochs. Based on two USNO B1.0 stars (Kann et. al
GCN 6918) (RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, R2=16.80;
RA (J2000) = 10:02:23.11, Dec. (J2000) = +45:41:41.1, R2=16.94) we
estimated brightness of the optical afterglow:
T0+ , Exposure, R_mag
(mid time)
1.9995 d 15x240 s 20.5 +/-0.1
2.979 d 20x180 s 20.8 +/-0.2
The message may be cited.
- GCN Circular #6957
M. Im, I. Lee (Seoul National University), and Y. Urata
(Saitama University) on behalf of the EAFON team:
Using the Mt. Lemmon (Arizona, US) 1.0m telescope
operated by the Korea Astronomy Space Science Institute,
we continued our observation of GRB071010B (GCN 6871,
Markwardt et al.), beginning at 10:53:09 UT on Oct 16,
(5.58 days after the trigger), and at 10:54:39 on Oct 19
(8.58 days after the trigger).
These observations reveal the optical afterglows again
(GCN 6873, Oksanen et al.), and the Oct. 19 data confirms
the break in the light curve reported earlier (GCN6935,
Kann et al.).
On the other hand, our Oct 16 photometry suggests that
the break started around Oct. 16 or later.
Photometry of the object is given below.
t_start (UT) Filter exp (sec) R-mag err
-----------------------------------------------------
Oct. 16,
10:53:09 R 17x300 21.2 0.1
Oct. 19,
10:54:39 R 8x300 22.0 0.3
This message may be cited.
- GCN Circular #6969
M. Im, I. Lee (Seoul National University), and Y. Urata
(Saitama University) on behalf of the EAFON team:
Using the Mt. Lemmon (Arizona, US) 1.0m telescope
operated by the Korea Astronomy Space Science Institute,
we continued our observation of GRB071010B (GCN 6871,
Markwardt et al.), beginning at 11:00:20 UT on Oct 21.
(10.59 days after the burst).
Now, the optical afterglow (GCN 6873, Oksanen et al.) is very faint,
and we have only a very marginal detection in our data.
The faintness of the afterglow further confirms the light curve break
(GCN6935, Kann et al.; GCN6957, Im, Lee, and Urata, et al.),
and the GRB is quickly fading.
Photometry of the object is given below.
t_start (UT) Filter exp (sec) R-mag err
-----------------------------------------------------
Oct. 21,
11:00:20 R 16x300 23.0 0.6
This message may be cited.
- GCN Circular #6977
V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884)
of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.19 between
(UT) 01:39:50 - 02:54:14 with Zeiss-1000 (Simeiz) telescope of CrAO
observatory. Based on USNO-A2.0 star RA (J2000) = 10 01 59.67, Dec.
(J2000) = +45 46 12.80, R=18.30 we estimated brightness of the optical
afterglow:
T0+, Exposure, R_mag, err
(mid time)
8.230 d 58x60 s 21.9 +0.37 -0.27
The message may be cited.
- GCN Circular #7041
K. Antonyuk, V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884)
of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.12 between
(UT) 01:01:50 - 02:03:27 with AZT-11 telescope of CrAO. Based on USNO-B1.0
star RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, R2=16.80 we
estimated brightness of the optical afterglow on a stacked image:
T0+, Exposure, R_mag, err
(mid time)
1.1989 d 12x300 s 20.70 +/-0.08
In comparison with the afterglow brightness obtained 2 and 3 days after
burst (Klunko et al. GCN 6945), where photometry used the same calibration
star, one can suggest either re-brightening between 1st and 3rd days, or at
least plateau on the light curve.
The message may be cited.
- GCN Circular #7329
K. Y. Huang, M. E. Schwamb, J. H. Wang, C. Y. Wen, and TAOS team
The 3 automatic 0.5-m telescopes of the TAOS (Taiwan American
Occultation Survey, located at Lulin Observatory) started to observe
GRB 071010B at 52s after the burst. The afterglow (Kann et al. GCN
6884) was detected in our 5s and 25s images. Due to twilight, the
TAOS telescopes stopped taking images around 4 minutes after the
burst. The afterglow, did not show significant decay but a mild increase
during our observations. Our high resolution data and other measurements
within 2 days indicate that GRB 071010B is composed of a slightly early
brightening behavior and a shollow decay (Wang et al.). We note that
special filter (5000-7200 A) was used in TAOS telescopes.
This message may be cited.
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