GRB 070610
GCN Circular 6559
Subject
GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
Date
2007-06-21T16:21:27Z (18 years ago)
From
Sabyasachi Pal at GMRT <spal@ncra.tifr.res.in>
Sabyasachi Pal (NCRA-TIFR) and Aritra Basu (Pune University, NCRA-TIFR)
report:
We observed the field of GRB 070610 (SWIFT J195509.6+261406) from MJD
54264.762 to MJD 54265.065, starting after 2.89 days of begining of
the burst (GCN 6489) using Giant Meterwave Radio Telescope (GMRT). The
observing central frequency was 610 MHz with a bandwidth of 16MHz. The
radio afterglow of the GRB was not detected and the peak radio flux
density at the optical afterglow position, measured by 1.5m OSN
telescope (GCN 6501), was 300 +- 150 microJy.
We thank the staff of the GMRT that made these observations possible.
GMRT is run by the National Centre for Radio Astrophysics of the Tata
Institute of Fundamental Research.
This message may be cited.
GCN Circular 6539
Subject
VLA upper limit on GRB 070610
Date
2007-06-15T17:03:01Z (18 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Dale A. Frail (NRAO) and Poonam Chandra (NRAO/UVA) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward GRB
070610 (GCN 6489) at a frequency of 8.46 GHz on 2007 June 15 at 13.67
UT for 1 hour. The GRB is undetected and the peak radio flux at the
optical afterglow position obtained from 1.5m OSN telescope (GCN 6501) is
80 uJy � 100 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 6536
Subject
SWIFT J195509.6+261406 (GRB 070610): further observations
Date
2007-06-15T01:27:13Z (18 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
Adria C. Updike (Clemson University), Peter A. Milne (Steward
Observatory), Grant G. Williams (MMT), Jason Puls, Dieter H. Hartmann
(Clemson University), Matt Wood (FIT), Josh Cardenzana (U Missouri -
Rolla), and Shelsea Pederson (MIT) report:
The SARA 0.9m telescope at Kitt Peak imaged the field of SWIFT
J195509.6+261406 (GRB 070610) on June 12 from 09:11:24 UT until 10:03:24
UT. Our observations consisted of 10 300 sec exposures in the R band.
The source was marginally detected in the exposure beginning at 09:26:55
UT, near our limiting magnitude of 21.16 +/- 0.4 It was not detected in
the other exposures.
Super-LOTIS observed the source on June 13. It made four passes of the
field, beginning at 06:03:20 UT, 08:08:20 UT, 09:48:20 UT, and 10:48:20
UT. The source was not detected in the individual or stacked images,
down to a maximum limiting R-band magnitude of 20.9 +/- 0.3 (as measured
on the second pass).
The SARA Homepage can be found at:
http://saraobservatory.org
This message may be cited.
GCN Circular 6532
Subject
SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
Date
2007-06-14T02:14:40Z (18 years ago)
From
Alexander Stefanescu at MPE <astefan@mpe.mpg.de>
A. Stefanescu (1), A. Slowikowska (2)(3), G. Kanbach (1), S. Duscha (1),
F. Schrey (1), H. Steinle (1), Z. Ioannou (4) of the OPTIMA-Burst Team
report the following:
(1)=MPE, Garching, (2)=FORTH, Heraklion (3)=NCAC, Torun (4)=Univ. of Crete
"OPTIMA-Burst at the 1.3m Skinakas Observatory of the University of
Crete, Greece continued observations of the OT associated with SWIFT
J195509.6+261406 (GRB 070610).
On 2007-06-12 we observed the source during 21:00-23:10 UT, using our
photon counting mode. In this period we detected flaring activity
consisting of only four short, dim flares:
t_start duration approx peak mag.
21:55:45 16s 18.9
22:23:13 18s 18.7
22:26:33 45s 18.4
22:34:14 17s 19.2
On 2007-06-13 we observed the source between 20:15-20:43 UT and
20:59-22:10 UT. We did not detect any flaring activity, the source
stayed below the background level detected by our photon counters at all
times. The brightness of a fluctuation 1 sigma above background noise
corresponds roughly to 21.4 mag.
We conclude that the flaring activity of the optical counterpart of
SWIFT J195509.6+261406 (GRB 070610) is greatly diminished, or may have
even come to an end."
This message may be cited.
[GCN OPS NOTE(17jun07): Per author's request, the two epoch dates
were corrected from "2007-06-13" to "2007-06-12" in the 2nd paragraph
and from "2007-06-14" to "2007-06-13" in the 3rd paragraph.]
GCN Circular 6520
Subject
SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
Date
2007-06-12T16:02:08Z (18 years ago)
From
Claudio Pagani at PSU/Swift-XRT <pagani@astro.psu.edu>
C. Pagani (PSU), C. B. Markwardt (CRESST/U.Md./GSFC), P. Evans (U. Leicester),
F. Gavriil (NPP/GSFC), J. A. Kennea (PSU), A. D. Falcone (PSU), W. Landsman
(NASA/GSFC) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift
Team:
We report on the continued SWIFT observations of the BAT trigger 281993,
originally designated GRB 070610.
We have collected 13.2 ks of XRT Photon Counting data in the T+3.1 ks to T+122
ks time interval. The X-ray light curve shows evidence of rapid variability,
with intense flaring activity and a possible late rebrightening.
Unlike a typical GRB afterglow, the lightcurve has shown no evidence of
overall fading.
We can exclude at this point a GRB afterglow origin of the counterpart
observed by the narrow field instruments. The BAT trigger 281993 is probably
a Galactic X-ray Transient, but we can not completely discard the possibility
of a GRB origin with an undetected X-ray counterpart.
In particular, an undetected afterglow from a short GRB (the T90 for
this trigger is 4.6 sec, GCN Circ. 6491) would not be unusual considering the
XRT observations started at T+3.1 ks. The flaring behavior reported by
ground based observations (GCN Circ. 6492, GCN Circ. 6501, GCN Circ. 6505,
GCN Circ. 6508) also favors the fast X-ray transient origin of the
counterpart. For additional details on the interpretations on the origin of
the source, refer to Markwardt et al. ATEL #1102.
The X-ray spectrum of the PC data in the T+3.1 ks to T+122 ks time interval,
modeled with an absorbed power law, gives a photon index of 1.8+/-0.3 with the
total column density consistent with the Galactic value of 1.01e22 cm**-2.
The absorbed (unabsorbed) 0.3-10.0keV average flux in the T+3.1 ks - T+122 ks
time interval is 2.4E-12 (3.9E-12) ergs cm^-2 s^-1.
We also note that in the XRT field of view we detect an additional X-ray
source 4.3 arcmin from the BAT refined position (and outside of the BAT 1.8
arcmin 90% error circle) that is most probably an X-ray active star. The
analysis of this source (designated SWIFT J195456.7+261301) will be reported
in a separate ATEL.
GCN Circular 6513
Subject
GRB 070610: TAROT Calern observatory optical observations
Date
2007-06-12T07:47:02Z (18 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP),
Gendre, B. (IASFC-INAF) report:
We imaged the field of GRB 070610 detected by SWIFT
(trigger 281993) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
The observations started 36.1s after the GRB trigger
(7.5s after the notice). The elevation of the field increased from
from 24 degrees above horizon and weather conditions
were good.
The date of trigger : t0 = 2007-06-10T20:52:26.400
The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT in the XRT location (Pagani et al.
GCNC 6506) with a limiting magnitude of:
t0+36.1s to t0+96.1s : R > 15.8
The second image is 30.0s exposure in tracking mode:
t0+102.7s to t0+132.7s : R > 16.7
We co-added a series of exposures:
t0+102.7s to t0+387.1s : R > 18.1
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 63.2980 lat= -1.0201
and the galactic extinction in R band is 2.5 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Circular 6512
Subject
GRB 070610: MITSuME OAO optical upper limit
Date
2007-06-12T07:07:28Z (18 years ago)
From
Michitoshi Yoshida at Okayama Astrophysical Obs <yoshida@oao.nao.ac.jp>
M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ)
and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:
We performed optical imaging observation (g', Rc, and Ic) of the
field of GRB 070610 (Pagani et al. GCN 6489) with 50cm MITSuME
telescope at Okayama Astrophysical Observatory from UT 12:27 to
UT 12:41 on Jun 11 2007.
We coadded 12 CCD frames for each band. Exposure time of each
frame is 1 minute. We made flux calibration using USNO B1.0
catalg. No new source was found at the position of the afterglow
candidate reported by A. de Ugarte Postigo (GCN 6501) and the XRT
source reported by Pagani et al. (GCN 6490). Three sigma limiting
magnitudes of our observation are listed below.
----------------------------------------------------
band mid-UT exp.time upper limit
g' Jun 11 12:34 12 x 1 min. 18.7 mag
Rc Jun 11 12:34 12 x 1 min. 19.0 mag
Ic Jun 11 12:34 12 x 1 min. 19.0 mag
----------------------------------------------------
GCN Circular 6508
Subject
GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
Date
2007-06-12T01:47:18Z (18 years ago)
From
Alexander Stefanescu at MPE <astefan@mpe.mpg.de>
A. Stefanescu (1), A. Slowikowska (2)(3), G. Kanbach (1), S. Duscha (1),
F. Schrey (1), H. Steinle (1), Z. Ioannou (4) of the OPTIMA-Burst Team
report the following:
(1)=MPE, Garching, (2)=FORTH, Heraklion (3)=NCAC, Torun (4)=Univ. of Crete
"OPTIMA-Burst at the 1.3m Skinakas Observatory, of the University of
Crete, Greece continued observations of the source reported on earlier
in GCN 6492 (Stefanescu et al.), GCN 6501 (de Ugarte Postigo et al.)
and GCN 6505 (Kann et al.)
Observations started at 20:40 UT, 0.991 days after the burst. Taking the
same reference star as Kann et al. (GCN 6505), we detect the source with
the following magnitudes in our CCD frames:
UT_mid T_GRB [d] t_exp I mag
20:42:38 0.99319 300 19.2
20:57:26 1.00347 1200 17.0
21:25:37 1.02304 300 20.7
21:31:19 1.02700 300 21.2
After this time, observations with the high-time-resolving main
instrument of OPTIMA-Burst commenced. The following describes a
quick-look analysis of 83min of data, binned to a time-resolution of 10s.
During it's low brightness periods, the source was not detected above
the noise in our photon counting detectors. However, we detected bright
flares with pronounced substructure around the following times:
UT T_GRB [d] duration (approx) peak brightness (preliminary!)
22:09 1.052 3.0 min 18.0 mag
22:20 1.060 7.5 min 17.4 mag
22:40 1.074 5.9 min 17.6 mag
In addition to these we detected 5 smaller flares at the 2.5 to 3 sigma
level, each lasting for about 1 minute and having a peak brightness of
about 19.7 mag.
Further observations and further analysis is in progress.
Since it seems strong variability is still in progress, we strongly
recommend further observations."
This message may be cited.
GCN Circular 6507
Subject
GRB 070610: SARA upper limit
Date
2007-06-11T21:25:03Z (18 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
Adria C. Updike, Dieter H. Hartmann (Clemson University), Gary Henson
(ETSU), Robert Mesler, Christina Bunker, and Jason Carson (ETSU/SARA REU
program) report:
We imaged the field of GRB 070610 (GCN 6489, Pagani et al.) beginning 10
hours and 53 minutes after the trigger (281993) with the SARA 0.9m at
Kitt Peak under decent weather conditions. In 30 minutes of stacked
exposures in the R band, we do not detect the optical transient (GCN
6492, Stefanescu et al.) down to a limiting magnitude of 19.8 +/- 0.2
based on calibration to 8 USNO B1.0 stars.
Due to the possible galactic nature of this source (Kann et al., GCN
6505), we encourage further observations.
The SARA Homepage can be found at:
http://saraobservatory.org
This message may be cited.
GCN Circular 6506
Subject
GRB 070610: Swift-XRT refined analysis
Date
2007-06-11T21:11:43Z (18 years ago)
From
Claudio Pagani at PSU/Swift-XRT <pagani@astro.psu.edu>
C. Pagani, J. L. Racusin and J. A. Kennea (PSU) report on
behalf of the Swift Team:
We have analysed the first 7.8 ks of Swift XRT photon counting mode data from
GRB 070610 (trigger number 281993, GCN Circ. 6489).
Because of an Earth limb constraint, the spacecraft did not slew promptly to
the BAT position and the XRT started collecting data in Photon Counting at
21:44:41 UT, 3140 seconds after the trigger.
Using 299 s of overlapping XRT Photon Counting mode and UVOT V-band data, we
find an astrometrically corrected X-ray position (using the XRT-UVOT alignment
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec=
298.79002, 26.2352 which is equivalent to:
RA (J2000): 19 55 9.60
Dec (J2000): +26 14 06.7
with an uncertainty of 4.3 arcsec (90% confidence).
This is 0.4 arcsec from the initial X-ray position (GCN Circ. 6490), 1.7
arcsec from the OSN optical candidate (GCN Circ. 6501) and 89 arcsec from the
BAT ground-calculated position (GCN Circ. 6491).
The XRT light curve created from the PC data in the T+3.1 ks to T+69 ks time
interval does not show the typical afterglow fading behavior, with evidence
of flaring activity and hints of a possible late rebrightening. More data
are being collected to monitor the light curve evolution.
The X-ray spectrum of the PC data, modeled with an absorbed power law with the
total column density fixed at the Galactic value of 1.01e22 cm**-2 gives a
photon index of 2.1+/-0.5.
The absorbed (unabsorbed) 0.3-10.0keV average flux in the T+3.1 ks - T+69 ks
time interval is 1.4E-12 (2.9E-12) ergs cm^-2 s^-1.
This circular is an official product of the Swift XRT team.
GCN Circular 6505
Subject
GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
Date
2007-06-11T20:41:38Z (18 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann, A. C. Wilson, S. Schulze, S. Klose, M. Henze, F. Ludwig, U.
Laux (TLS Tautenburg) and J. Greiner (MPE Garching) report:
We observed the XRT position (Pagani & Kennea, GCN 6490) of Swift GRB
070610 (Pagani et al. GCN 6489) with the Tautenburg 1.34m Schmidt
Telescope in Rapid Response Mode (Klose et al., GCN 3609). Observations
started 640 seconds after the trigger, at an initial airmass of 1.945.
Weather conditions were good and the airmass decreased during
observations. We obtained two sequences of images with 120 seconds
exposure time each, consisting of 6 Ic, 3 Rc and 3 V images per sequence.
The optical transient first detected by Stefanescu et al. (GCN 6492) and
confirmed by de Ugarte Postigo et al. (GCN 6501) is detected in only three
images, thus showing a rapid, short-lived flaring behaviour. Stacks of
images were created, but we do not detect the transient in these stacks.
We report the following upper limits and magnitudes assuming the USNO B1.0
star at RA = 19:55:03.2, Dec. = +26:14:14.5 has R2 = 15.8 and I = 15.32:
tmid (days) filter Exp. Limit OT mag
0.008407 Ic 1x120 19.7
0.012122 Ic 6x120 20.2
0.022194 Rc 3x120 21.2
0.033376 Ic 2x120 20.4
0.036369 Ic 1x120 20.2 19.36 +\- 0.15
0.040228 Ic 3x120 20.5
0.044356 Rc 1x120 21.3
0.046336 Rc 1x120 21.3 20.89 +\- 0.20
0.048304 Rc 1x120 21.3 21.78 +\- 0.50
The final detection is marginal.
We note that this flaring behaviour is very uncommon for the afterglow of
a GRB. Furthermore, the maps of Schlegel et al. 1998 give E(B-V) = 3.256,
tranlating to A_R = 8.7 and A_I = 6.3, at the position of the transient.
This would imply the flare in the I band reached 13th magnitude, very
unusual at such a late time. Furthermore, the X-ray afterglow as seen on
the Swift XRT repository webpage
(http://www.swift.ac.uk/xrt_curves/00281993/index.php) shows a more or
less constant behaviour, with small flares superposed.
The behaviour of the transient in both the optical and the X-ray regime as
well as the location in the Galactic plane strongly suggest that this is a
new Galactic transient source and not a GRB and its associated afterglow.
This message may be cited.
[GCN OPS NOTE(12jun07): Per author's request, "A_V" was changed to "A_I".]
GCN Circular 6501
Subject
GRB 070610: Optical observations from OSN
Date
2007-06-11T14:51:12Z (18 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo, A.J. Castro-Tirado, F. Aceituno
(IAA-CSIC) on behalf of a larger collaboration report:
"We have imaged the field of GRB 070610 (Pagani et al.
GCNC 6489) with the 1.5m OSN telescope in Granada
(Spain) using V, R and I filters. The observations were
obtained starting at 02:44:55 UT (5.87 hours after the
burst). Inside the XRT error box (Pagani et al. 6490) we
detect the afterglow reported by Stefanescu et al.
(GCNC 6492) with R~21.5 at the following coordinates
(J2000) with an uncertainty of 0.5 arcsec:
A.R.: 19:55:09.63
Dec.: +26:14:05.6
A finding chart can be found at:
http://www.iaa.es/~deugarte/GRBs/070610/GRB070610.gif "
This message may be quoted.
GCN Circular 6500
Subject
GRB 070610: Watcher Observations
Date
2007-06-11T14:30:29Z (18 years ago)
From
John French at UCD,Ireland <jfrench@bermuda.ucd.ie>
John French, Gary Melady (University College Dublin), Petr Kubanek,
Martin Jelinek (IAA CSIC Granada, Spain)
on behalf of the Watcher collaboration report:
The Watcher 40cm robotic telescope, located at Boyden Observatory, South
Africa, began imaging the field of GRB 070610 (Pagani et al., GCN
6489) at 20:53:19 UT, 53s after the Swift trigger (23s after receipt of
the GCN notice).
Our first 10s unfiltered exposure shows no new source in the XRT error
box (Pagani et al., GCN 6490) down to an R-band limiting magnitude of
approx. 15.1 (in comparison to USNO-B1).
A series of unfiltered 10s exposures were combined to create a 548s
exposure, with a mean time of 20:57:48 UT (269s after the trigger). No
new source was detected in this image down to an R-band limiting
magnitude of approx. 17.5.
This message may be cited.
GCN Circular 6493
Subject
GRB 070610: Swift-UVOT Upper Limits
Date
2007-06-11T00:43:56Z (18 years ago)
From
Wayne Landsman at GSFC/SSAI <landsman@milkyway.gsfc.nasa.gov>
W. Landsman (NASA/GSFC), F.E. Marshall (NASA/GSFC) and C. Pagani (PSU)
report on behalf of the Swift/UVOT team.
UVOT took a finding chart exposure of 61 seconds of the field of GRB
070610 (Pagani et al., GCN 6489) with the White (160-650 nm) filter
starting 3131 seconds after the BAT trigger. The UVOT finding chart
was delayed was due to an Earth limb constraint.
No afterglow candidate has been found within the 8.2" XRT error circle
(Pagani et al., GCN 6490) to a 3 sigma magnitude upper limit of 19.4.
No correction has been made for the expected large extinction at a
Galactic latitude of -1 deg.
GCN Circular 6492
Subject
GRB 070610: OPTIMA-Burst high-time-resolution optical observations
Date
2007-06-11T00:22:55Z (18 years ago)
From
Alexander Stefanescu at MPE <astefan@mpe.mpg.de>
A. Stefanescu (1), A. Slowikowska (2)(3), G. Kanbach (1), S. Duscha (1),
F. Schrey (1), H. Steinle (1), Z. Ioannou (4) of the OPTIMA-Burst Team
report the following:
(1)=MPE, Garching, (2)=FORTH, Heraklion (3)=NCAC, Torun (4)=Univ. of Crete
"OPTIMA-Burst at the 1.3m Skinakas Observatory, of the University of
Crete, Greece slewed to the Swift BAT-errorcircle of GRB 070610 (GCN
Circ 6489, C. Pagani et al.) and started observations at 20:53:23UT (57s
after the burst, 28s after the notice).
We detected a faint transient in the BAT errorcircle. The transient was
marginally detected as 19+-0.4 mag in our first 10s white-light image,
and was not detected in subsequent CCD frames. The position of the
transient is inside the XRT error-circle (GCN 6490, C. Pagani et al.).
At 20:57:19 (293s after the burst) observations with the fibre-fed,
single-photon-counting high-time-resolution main instrument of
OPTIMA-Burst started. A quick-look analysis of this data binned to 1s
resolution indicates that the source is barely detectable (below the 2
sigma level) until 21:00:22 (476s after the burst). At that time the
source showed a flaring activity of about 7.5 sigma above the background
level. The activity lasted about 80s and consisted of three to four
overlapping spikes and a slow decay.
Further analysis is in progress."
This message may be cited.
GCN Circular 6491
Subject
GRB 070610, Swift-BAT refined analysis
Date
2007-06-11T00:01:17Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
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), C. Pagani (PSU),
D. Palmer (LANL), A. Parsons (GSFC), 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-239 to T+427 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 070610 (trigger #281993)
(Pagani, et al., GCN Circ. 6489). The BAT ground-calculated position is
RA, Dec = 298.805, 26.256 deg which is
RA(J2000) = 19h 55m 13.1s
Dec(J2000) = 26d 15' 20"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 52%.
The mask-weighted light curve shows a single peak starting at ~T-2 sec
and ending at ~T+6 sec. T90 (15-350 keV) is 4.6 +- 0.4 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.8 to T+4.4 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.76 +- 0.25. The fluence in the 15-150 keV band is 2.4 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.76 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
GCN Circular 6490
Subject
GRB 070610; Swift-XRT position
Date
2007-06-10T23:57:12Z (18 years ago)
From
Claudio Pagani at PSU/Swift-XRT <pagani@astro.psu.edu>
C. Pagani & J. A. Kennea (PSU) report on behalf of the Swift-XRT team:
We have analyzed the first 2.3 Ks of prompt downlinked data for GRB 070610
(trigger=281993, GCN Circ. 6489). Because of an Earth limb constraint, the
spacecraft did not slew promptly to the BAT position and the XRT observations
started 3.2 Ks after the BAT Trigger.
In the BAT error circle we find an uncatalogued source at position
RA, Dec 298.7900, 26.2351 which is
RA(J2000) = 19 55 09.6
Dec(J2000) = +26 14 06.3
with an uncertainty of 8.2 arcsec (radius, 90% containment).
The XRT position is 77arcsec from the BAT on board position (GCN Circ. 6489),
within the BAT error circle. We are waiting for additional downlinked data to
assess the fading behavior of the proposed X-ray afterglow.
This circular is an official product of the Swift-XRT team.
GCN Circular 6489
Subject
GRB 070610: Swift detection of a burst
Date
2007-06-10T21:03:23Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
C. Pagani (PSU), S. D. Barthelmy (GSFC), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), D. Grupe (PSU),
S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU),
C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), D. M. Palmer (LANL),
A. M. Parsons (GSFC), M. Stamatikos (NASA/ORAU) and L. Vetere (PSU)
report on behalf of the Swift Team:
At 20:52:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070610 (trigger=281993).
The BAT on-board calculated location is
RA, Dec 298.795, +26.214 which is
RA(J2000) = 19h 55m 11s
Dec(J2000) = +26d 12' 49"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single peak
with a duration of about 10 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~3 sec after the trigger.
Because of an Earth limb constraint, the spacecraft did not slew promptly
to the BAT position, and so there are no immediate XRT or UVOT data products
to analyze. XRT and UVOT will begin observing this target at 21:42UT.