GRB011212 = XRF011212: HETE/ASM Error Region

Overlap of HETE/WXM and RXTE/ASM Error Regions

The WXM error region for burst GRB011212 has been refined. At right, we show the intersection of the HETE/WXM and the RXTE/ASM error regions. The error regions are all 90% confidence regions; coordinates are J2000.

The error region of GRB011212 as defined by the HETE/WXM and RXTE/ASM.
Click on image for the a PostScript version of this plot!


GCN Circulars on GRB011212

GCN Circular #1194: Detection of the source

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1194
SUBJECT: GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
DATE:    01/12/12 14:19:13 GMT
FROM:    Don Lamb at U.Chicago  

GRB011212 (=XRF011212) (=H10001): An X-ray Flash/X-ray Rich GRB Detected by
HETE

G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team;

N. Butler, G. Crew, J. Doty, G. Monnelly, G. Prigozhin, R. Vanderspek,
J. Villasenor, T. Cline, J.G. Jernigan, A. Levine, F. Martel,
E. Morgan, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the
HETE Operations and HETE Optical-SXC Teams;

N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii,
T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner,
C. Graziani, and T. Donaghy, on behalf of the HETE WXM Team;

J-L Atteia, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf
of the HETE FREGATE Team;

write:

The HETE Fregate and WXM instruments have detected and localized a
burst at 14642.00 SOD {04:04:02.00} UT on 12 December.  The burst was
an untriggered event, and appears to be an X-ray rich GRB with a
duration of > 80 seconds.

In the Fregate 8-85 keV band, the statistical significance was 9.8
sigma. A total of 3724 counts were detected during that interval,
corresponding to a fluence of ~6.7 x 10-7 cm-2. The peak flux was
~1.8 x 10-8 ergs cm-2 s-1 (i.e., ~0.5 x Crab flux), assuming a
Crab-like spectrum. In the WXM 2-25 keV band, the statistical
significance was 6.9 sigma.

Based on the WXM data, the best fit location for GRB011019 is:

RA = 05h00m05s, Dec = +32o07'39"

with a total error radius of 11 arcminutes (90% confidence region).

The duration in the WXM 2-10 keV band was > 80 s. A total of ~3500
counts were detected during that interval.

Further refinement of the burst localization is in progress.

Possible Optical Counterparts

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1324
SUBJECT: GRB011212: Optical Observations
DATE:    02/04/03 17:11:02 GMT
FROM:    George Ricker at MIT  

GRB011212: Optical Observations

A. Dullighan, G. Monnelly, G. Ricker, R. Vanderspek, N. Morgan (MIT);
and D. Tholen (U.Hawaii)

write:

We have observed the error box of the HETE GRB011212 (GCN #1194) with
the Baade 6.5m telescope at Magellan on 2001 December 14.17 UT (Epoch
1) and December 15.17 UT (Epoch 2) using the MagIC CCD detector.
Twelve 360s R-band exposures were used to mosaic the entire HETE and
RXTE/ASM joint error box on each night.  Both nights had a seeing of
0.7" with a limiting magnitude of 24.5, except for the last half of
the second night when the seeing decreased slowly to 1.3", with a
limiting magnitude of 24.0 on the last frame.  Third epoch
observations were made with the University of Hawaii 2.2m telescope on
Mauna Kea on 2002 February 16.33 and 17.38 UT.  Three frames were used
to mosaic the error box each with three 600s VR-band exposures under
conditions of 1.3" seeing, giving a limiting magnitude of 24.5 after
summing.

Aperture photometry was performed on all objects detected in the
Epoch 1 images and then again at the same positions in the later
epochs.  The absolute magnitude of each source was calculated using a
nearby USNO catalog star: for each source, the same calibration star
was used in all epochs, and the quoted error in the magnitude does not
include the uncertainty in the magnitude of the calibration star.
Comparison with Epoch 3 is complicated by the fact that it is in
VR-band, whereas Epochs 1 and 2 are in R-band.  Four sources were
determined to have faded between both Epochs 1 and 2 and between
Epochs 1 and 3.  Their positions and magnitudes are listed below.
Sources 2, 3, and 4 faded to near the detection limit in Epoch 2, and
to below the detection limit in Epoch 3.  The observed fading and
upper limits are consistent with a temporal power law decay index
between -1 and -2, except for source 1 in Epoch 3, but this flattening
of the decay could be due to an underlying galaxy.

grb event: 2001 December 12.1695 UT
Epoch 1:   2001 December 14.17	2.0 days after
Epoch 2:   2001 December 15.17 	3.0 days
Epoch 3:   2002 February 16.33 	66.2 days
            2002 February 17.38 	67.2 days

Fading Sources
     RA       Dec        Epoch 1 m(R)    Epoch 2 m(R)     Epoch 3 m(VR)
1  4:59:58.1 +32:02:57  23.14 +/- 0.12  23.89 +/- 0.22   24.08 +/-0.24
2  4:59:59.4 +32:03:43  23.80 +/- 0.18  24.65 +/- 0.39    > 24.5
3  4:59:59.0 +32:09:04  23.75 +/- 0.18  24.80 +/- 0.48    > 24.5
4  4:59:39.5 +32:08:34  23.38 +/- 0.12  24.41 +/- 0.38    > 24.5

Finder charts have been prepared of the four sources from the Epoch 1
observations at http://space.mit.edu/HETE/Bursts/GRB011212.  The
charts contain the source, marked by crosshairs, a bright star (B)
from the USNO catalogue, and a constant star (C) of comparible
magnitude to the source.  The charts have a width and height of 33
arcseconds in RA and Dec.  North is up and East is to the left.

Source#    m(R)               Star B m(R)        Star C m(R)
  1         23.14 +/- 0.12     18.8(USNO)        23.65 +/- 0.15
  2         23.80 +/- 0.18     16.9(USNO)        23.59 +/- 0.15
  3         23.75 +/- 0.18     14.4(USNO)        23.48 +/- 0.14
  4         23.38 +/- 0.12     16.8(USNO)        23.11 +/- 0.09

Finding charts of possible transient sources in the error region of GRB011212


Click for PostScript version!

Source #1

     RA       Dec        Epoch 1 RMag.   Epoch 2 RMag.    Epoch 3 RMag.
  4:59:58.1 +32:02:57  23.14 +/- 0.12  23.89 +/- 0.22   24.08 +/- 0.24

The finder chart is 33 arcseconds square.
North is up and East is to the left.

R Band Magnitudes
Source 1   23.14 +/- 0.12       
Star B     18.8 (USNO)              
Star C     23.65 +/- 0.15       


Click for PostScript version!

Source #2

     RA       Dec        Epoch 1 RMag.   Epoch 2 RMag.    Epoch 3 RMag.
  4:59:59.4 +32:03:43  23.80 +/- 0.18  24.65 +/- 0.39     < 24.5

The finder chart is 33 arcseconds square.
North is up and East is to the left.

R Band Magnitudes
Source 2   23.80 +/- 0.18  
Star B     16.9 (USNO)
Star C     23.59 +/- 0.15



Click for PostScript version!

Source #3

     RA       Dec        Epoch 1 RMag.   Epoch 2 RMag.    Epoch 3 RMag.
  4:59:59.0 +32:09:04  23.75 +/- 0.18  24.80 +/- 0.48     < 24.5

The finder chart is 33 arcseconds square.
North is up and East is to the left.

R Band Magnitudes
Source 3   23.75 +/- 0.18       
Star B     14.4 (USNO)              
Star C     23.48 +/- 0.14       


Click for PostScript version!

Source #4

     RA       Dec        Epoch 1 RMag.   Epoch 2 RMag.    Epoch 3 RMag.
  4:59:39.5 +32:08:34  23.38 +/- 0.12  24.41 +/- 0.38     < 24.5

The finder chart is 33 arcseconds square.
North is up and East is to the left.

R Band Magnitudes
Source 4   23.38 +/- 0.12
Star B     16.8 (USNO)      
Star C     23.11 +/- 0.09