GRB 021112
GCN Circular 1682
Subject
GRB021112 (=H2448): A Long GRB Localized by HETE
Date
2002-11-12T15:54:15Z (23 years ago)
From
George Ricker at MIT <grr@space.mit.edu>
GRB021112 (=H2448): A Long GRB Localized by HETE
E. Fenimore, Y. Shirasaki, C. Graziani, M. Matsuoka, T. Tamagawa, K.
Torii, T. Sakamoto, A. Yoshida, M. Galassi, T. Tavenner, T. Donaghy,
Y. Nakagawa, D. Takahashi, M. Suzuki, R. Satoh, and Y. Urata, on
behalf of the HETE WXM Team;
G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of
the HETE Science Team;
N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek, J.
Villasenor, T. Cline, J. G. Jernigan, A. Levine, F. Martel, E.
Morgan, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on
behalf of the HETE Operations and HETE Optical-SXC Teams;
M. Boer, J-F Olive, J-P Dezalay, C. Barraud and K. Hurley on behalf
of the HETE FREGATE Team;
write:
At 03:28:15.89 UTC (12495.89 s UT) on 12 Nov 2002, the HETE FREGATE
and WXM instruments detected event H2448, a long GRB.
Ground analysis of the WXM data for the burst produced a location
which was reported in a GCN Position Notice at 04:49 UT, 81 minutes
after the burst. Further ground analysis of the WXM data produced a
refined location, which was reported in a second GCN Position Notice
at 05:29 UT. At the time that the second GCN Position Notice was
issued, we noted that a transcription error had resulted in an error
of 1 degree in the value of the declination cited in the 04:49 UT
Notice.
The WXM localization SNR was 4. The refined WXM ground location can
be expressed as a 90% confidence circle that is 20 arcminutes in
radius and is centered at
RA = +02h 36m 52s, Dec = +48d 50' 56" (J2000).
The burst duration in the 8-40 keV band > 5s. In the 8-40 keV band,
the burst duration was > 3s, and the peak flux was > 3 x 10-8 ergs
cm-2 s-1 (ie > 1 x Crab flux). In the 25-400 keV band, the burst
duration was > 4s.
A light curve for GRB021112 is provided at the following URL:
http://space.mit.edu/HETE/Bursts/GRB021112/
This message is citable.
GCN Circular 1684
Subject
GRB 021112: R-band search
Date
2002-11-12T21:50:55Z (23 years ago)
From
Andrew Levan at U.of Leicester <anl@star.le.ac.uk>
A.J. Levan (Leicester), J.J. Kavelaars (HIA/NRC) and J.E Rhoads (STScI)
report for a larger collaboration.
The error box of GRB 021112 (GCN 1682) was imaged with the KPNO-4m using
the Mosaic imager beginning on November 12th 06:43 UT (3.25 hours after
burst). Four R-band images were obtained dithered to cover the entire
HETE-2 error circle. Most of the area was covered by all four
exposures, yielding a net total exposure time of 1680s.
Visual comparison of the stacked image with the DSS-2 (R-band) reveals
no obvious new sources.
Further observations are planned.
GCN Circular 1685
Subject
GRB 021112: Optical Observations
Date
2002-11-13T00:16:11Z (23 years ago)
From
Melissa Nysewander at UNC,Chapel Hill <mnysewan@physics.unc.edu>
J. Schaefer, S. Savage, R. Canterna (U. Wyoming), M. Nysewander, and D.
Reichart (U. North Carolina) report:
We observed the inner 90% of the 40-arcminute diameter error circle of GRB
021112 (GCN 1682) with the 0.6-meter Red Buttes Observatory telescope
beginning 1.8 hours after the burst. We integrated without filter for 1800
seconds per pointing x four pointings.
Visual comparison with the DSS2-Red reveals no obvious counterpart to the
limiting magnitude of the DSS.
[GCN OPS NOTE (13nov02): The Circ 1683 reference was changed to 1682.]
GCN Circular 1689
Subject
GRB 021112: RAPTOR Observations
Date
2002-11-13T23:21:48Z (23 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W. T. Vestrand, K. Borozdin, S. Brumby, D. Casperson,
M. Galassi, K. McGowan, D. Starr, R. White, and P. Wozniak report:
One of our RAPTOR (RAPid Telescopes for Optical Response) wide-field
telescope arrays responded to the HETE-2 alerts for GRB 021112
(trigger #2448). That array, located in Los Alamos, New Mexico, is
composed of four Canon 85 mm f1.2 telephoto lenses, which together
image approximately 1300 squares degrees, and a central "fovea"
telescope employing a 400 mm f2.8 Canon telephoto lens that images a
central 16 square degree field. An unfiltered Apogee AP-10 CCD camera
is located at the focal plane of each telescope.
Mosaic imaging of the HETE-2 field-of-view began at 3:29:01 UTC, just
45.4 s after the GRB trigger. All of the images of the burst location
taken before the GRB position was released place the location of the
burst just 100 pixels from the edge of the imager where vignetting
causes a significant loss of sensitivity. The image sensitivity was
further reduced by thin cirrus clouds which were apparent in all of
the early images. No new objects were detected within the HETE-2
error circle after comparison with archival images. The following
limits were obtained for the initial response images:
Exposure Time since Exposure Limiting Imager
start time trigger duration Magnitude
(UTC) (minutes) (seconds) (5 sigma)
---------------------------------------------------------------
3:29:56 1.67 5 11.4 wide-field
3:32:49 4.55 30 11.7 wide-field
4:49:44 81.46 30 14.6 fovea
This message is citable.
GCN Circular 1695
Subject
GRB021112: Optical Observations
Date
2002-11-15T21:31:17Z (23 years ago)
From
Don Lamb at U.Chicago <lamb@oddjob.uchicago.edu>
P. R. Newman, D. Q. Lamb, D. L. Tucker, S. Allam, B. C. Lee, D. E.
Vanden Berk, M. Harvanek, A. N. Kleinman, S. Kleinman, J. Krzesinski,
D. Long, and S. Snedden, on behalf of the SDSS GRB team, report:
We have observed the field of GRB021112 (=H2448) (E. Fenimore et al.,
GCN 1682) using the SDSS 0.5-m "Photometric Telescope" (PT) at APO
under clear skies and poor seeing on UTC 2002 November 12 from 07:51
to 10:20 UTC, beginning less than 4.4 hours after the burst. We took a
series of five 500-second g'-band exposures and five 500-second r'-band
exposures (41.5' x 41.5' field of view), each of which covers the
entire refined HETE error circle for GRB021112. Visual comparison of
the r'-band images with the DSS-2 (R band) reveals no new object,
confirming the result reported by A. J. Levan et al. (GCN 1684).
This message is citable.
GCN Circular 1696
Subject
GRB 021112: Variable Source in R-band search
Date
2002-11-18T22:49:28Z (23 years ago)
From
James Rhoads at STScI <rhoads@stsci.edu>
L. Strolger, J. E. Rhoads, A. Fruchter, I. Burud (STScI); A. J. Levan
(Leicester), and J. J. Kavelaars (McMaster) report.
In follow-up to our observations reported in GCN 1684, additional
observations of the GRB 021112 error box (GCN 1682) were made using the
KPNO-4m + Mosaic I imager on UT 2002 November 13.2. Four R-band images
were obtained dithered to cover the entire HETE-2 error circle, for a
combined exposure time of 1680s. Further detailed analysis of the
field, including localized registration, PSF-matching, and subtraction
of the combined observations made Nov. 12.3 from the combined
observations made Nov. 13.2 have revealed a candidate optical transient
(OT) located just outside the HETE-2 90% error circle, at
RA: 02:38:27.80 Dec: +48:33:18.4 (J2000.0)
Coordinates and offsets from neighboring stars were determined from
direct comparison to the DDS-2 (R-band). A source is visible at the
limit of the DDS-2 red plate at the position of the variable object.
PSF photometry performed on the candidate OT and 5 neighboring stars have
shown the object apparently brightened by 0.55 +/- 0.03 magnitudes between
the observations made on Nov. 12.3 and Nov 13.2.
Further information summarizing the discovery and analysis
can be found on http://www.stsci.edu/~fruchter/GRB/021112/ .
An approximate photometric zero point (based only on the typical throughput
for the camera) gives R=21.1 on Nov 12.3 and R=20.6 on Nov. 13.2.
Local reference star magnitudes are given on the above web page to
facilitate comparison with other data.
GCN Circular 1697
Subject
GRB021112, BVRI field photometry
Date
2002-11-19T02:56:54Z (23 years ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have acquired shallow BVRcIc all-sky photometry for
a 20x20 arcmin field centered about 7arcmin north and 7 arcmin
west of the position of the variable source mentioned in
Strolger et al. (GCN1696), but within the error box for
GRB021112 (Fenimore et al.,GCN1682), using the USNOFS 1.0-m telescope
on one marginal night. Stars brighter than V=13.0 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/grb021112.dat
The astrometry in this file is based on linear plate solutions
with respect to USNO-A2.0.
While the night was photometric, there was poor and variable
seeing due to a frontal passage. We estimate the present zeropoint
errors to be about 0.03mag. If the variable source is confirmed
to be the afterglow for GRB021112, we will extend the calibration
with additional nights to guard against a systematic zeropoint error.
You should check the dates on the .dat file prior to final publication
to get the latest photometry.
GCN Circular 1698
Subject
GRB 021112, Radio Observations
Date
2002-11-19T17:59:03Z (23 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
D. A. Frail (NRAO), and E. Berger (Caltech) report on behalf of a
larger collaboration:
"We have used the VLA to observe a variable candidate located just
outside of the HETE 90% error circle. There is no 8.46 GHz radio
source at the position reported by Strolger et al. (GCN1696) to a
limit of 100 microJy (3-sigma).
No further observations are planned."
GCN Circular 1701
Subject
GRB 021112: Afterglow or Variable Star?
Date
2002-11-20T19:05:03Z (23 years ago)
From
Melissa Nysewander at UNC,Chapel Hill <mnysewan@astro.unc.edu>
M. Nysewander, D. Reichart (U. North Carolina), A. Henden (USRA/USNO), G.
G. Williams (MMTO/SAO), and M. Schwartz (Tenagra Observatories) report on
behalf of a larger collaboration:
We observed fields containing the candidate afterglow of GRB 021112 (GCN
1696) 4 days after the burst in BVRcIc, 6 days after the burst in Rc, and 7
days after the burst in H. Using the field calibration of Henden (GCN
1697) and 2MASS, we report preliminary photometry:
Date Time Filter Magnitude Telescope
Nov 16.2 4.0 days V 21.48 +- 0.08 90-inch Bok
Nov 16.3 4.1 days B > 22.6 (3 sigma) 90-inch Bok
Nov 16.3 4.1 days Ic 19.39 +- 0.09 32-inch Tenagra II
Nov 16.3 4.1 days Rc 20.87 +- 0.07 32-inch Tenagra II
Nov 18.3 6.1 days Rc 20.84 +- 0.06 1.0-meter USNO
Nov 19.2 7.0 days H * 17.44 +- 0.17 1.55-meter USNO
* 2MASS field not available. Calibration based on 2MASS Quicklook image
and consequently caution is warranted. However, candidate is strongly
detected: Internal errors are ~0.01 mag.
Using the images of Strolger et al. (GCNs 1684, 1696), kindly provided by
J. E. Rhoads, we have placed their photometry on the same photometric
system:
Date Time Filter Magnitude Telescope
Nov 12.3 3.2 hours Rc 20.86 +- 0.05 4-meter Mayall
Nov 13.2 1.0 days Rc 20.31 +- 0.06 4-meter Mayall
Although we do not find evidence for variability in the R-band light curve
outside of the discovery epoch, which could be explained by an afterglow in
a R = 20.86 +- 0.03 galaxy, 1.0 arcsec seeing on Oct. 19th shows the
candidate to have a star-like profile (this image is available upon
request).
This, in addition to the candidate's location outside of HETE's 90% error
box and an otherwise rarely seen brightening a day after the burst, suggest
that the candidate is probably a variable star of some type instead of an
afterglow in a bright, compact galaxy.
[GCN OPS NOTE (27Nov02): All the "Oct dd.dd" were changed to "Nov dd.d".]
GCN Circular 1776
Subject
GRB 021112: Evidence for Another Dark Optical Afterglow
Date
2002-12-22T00:16:58Z (22 years ago)
From
Melissa Nysewander at UNC,Chapel Hill <mnysewan@astro.unc.edu>
J. Schaefer, S. Savage, R. Canterna (U. Wyoming), M. Nysewander, D.
Reichart (U. North Carolina), A. Henden (USRA/USNO), and D. Lamb (U.
Chicago) report on behalf of a larger collaboration:
We observed the inner 93% of the 40-arcminute diameter error circle of GRB
021112 (GCN 1682) with the 0.6-meter Red Buttes Observatory telescope
beginning 1.8 hours (GCN 1685) and 13.9 days after the burst. For the
first epoch observation, we integrated without filter for 1800 seconds per
pointing x four pointings. For the second epoch observation, we integrated
without filter for 2700 seconds per pointing x four pointings.
Unfiltered magnitudes measured with our Apogee AP8P CCD best mimic Rc
magnitudes. Using the image subtraction routine ISIS2 (Alard 2000), we
find no candidates to the limiting magnitude of our first epoch image,
which we measure to be Rc = 21.8 mag (3 sigma), 22.2 mag (2 sigma), and
23.0 mag (1 sigma) using the field calibration of Henden (GCN 1697).
We note that the Galactic extinction along this line of sight is
approximately A_Rc = 0.52 mag (Schlegel et al. 1998).
The candidate of Strolger et al. (GCNs 1684, 1696) sits outside of the
above fields. In addition to the arguments presented by Nysewander et al.
(GCN 1701), its BVRcIcH spectral flux distribution and low Galactic
latitude suggest that it is a low-mass flare star.
Dismissing this candidate, this is the deepest non-detection of an optical
afterglow beginning within 2.6 hours of a burst (GCN 1699).
Alard, C. 2000, A&AS 114, 363
Schlegel, D., et al. 1998, ApJ, 500, 525