GRB 020321
GCN Circular 1385
Subject
GRB020321 : Optical observations.
Date
2002-05-06T10:43:33Z (23 years ago)
From
Isabel Salamanca at U. of Amsterdam <isabel@science.uva.nl>
Isabel Salamanca, Evert Rol, L. Kaper (Univ. of Amsterdam),
A. J. Castro-Tirado (IAA-CSIC Granada), A. Fruchter (STScI, Baltimore),
J. Greiner (MPE Garching and AI Potsdam), J. Hjorth, (Univ. of Copenhagen),
E. Pian (INAF, OA Trieste), E. van den Heuvel (Univ. of Amsterdam),
on behalf of GRACE report:
Deep broad-band images of the NFI error box (GCN 1285 & 1348) and WFC
error box (GCN 1281 & 1284) of GRB 020321 were obtained with EFOSC at
the 3.6m telescope at ESO, La Silla.
The log of observations follows below:
Date (2000) exposure Filter lim mag (3 sigma)
==========================================================
March 21/22 900 sec/each UBVR U=22.4 B=24.1 V=23.6 R=23.8
March 23/24 900 sec/each VR V=23.7 R=23.6
April 18/19 1200 sec R R=23.6
Magnitudes were calibrated by using the standard star WOLF 629 of the
Landolt catalogue, observed during the first night, which was photometric.
Very close to the position of the X-ray counterpart reported by in 't
Zand et al. (GCN 1348) we found two objects which are not present in the DSS,
with coordinates:
Source RA(J2000) DEC(J000) error
A 16h 12m 44.1s, -83d 43' 09.2" 0.5 arcsec
B 16h 12m 44.4s, -83d 43' 15.5" 2 arcsec
X-ray 16h 12m 43.7s, -83d 43' 13.9" 4 arcsec
Their magnitudes at the three epochs are:
(March 21.18102 BURST TRIGGER in BeppoSAX)
Epoch UT(2002) Filter Source A Source B
===========================================================
March 22.2814 R 20.81 +/-0.03 22.84 +/- 0.11
March 22.3179 V 21.43 +/-0.03 22.98 +/- 0.14
March 22.4260 B 22.79 +/-0.08 23.84 +/- 0.21
March 22.4378 U > 23.6 > 23.6
March 24.3958 R 20.78 +/-0.04 23.30 +/- 0.22
March 24.4076 V 21.47 +/-0.05 23.54 +/- 0.30
April 19.2908 R 20.93 +/-0.04 23.68 +/- 0.26
-------
Note: UTs are mid-exposure.
Both sources are extended. Source "A" does not appear in the DSS 2
(red), although it has a magnitude similar to other stars
that are barely visible in the DSS image. However, it does not show
any clear fading behaviour as would be expected from a GRB optical
afterglow.
Source "B" consists of two 'blobs', one of which disappears at epochs
2 and 3. The decrease in magnitude is too shallow for the usual
power-law behaviour of an afterglow: the index alpha would be ~0.2,
while for gamma-ray afterglows alpha is usually around 1. However,
this could be consistent with an OT superposed on its host-galaxy.
Images in V and R for the three epochs, as well as a light curve can
be found at http://zon.wins.uva.nl/~isabel/GRBs/GRB020321/grb020321.html
This message can be cited.
GCN Circular 1348
Subject
X-ray afterglow of GRB020321
Date
2002-04-10T12:09:39Z (24 years ago)
From
Jean int Zand at SRON <jeanz@sron.nl>
J.J.M. in 't Zand, University of Utrecht and Space Research
Organization Netherlands (SRON); L. Kuiper and J. Heise, SRON; L. Piro
and G. Gandolfi, Istituto di Astrofisica Spaziale e Fisica Cosmica,
Rome, report:
"A refined analysis of the BeppoSAX Narrow Field Instruments data on
GRB 020321, collected between 8.1 and 10.6 hrs after the burst, has
resulted in a significance of only 3.0 for the tentative X-ray afterglow
detection reported in GCN 1285. The source is also not confirmed by
the XMM-Newton observation that took place between 10.3 and 24.2 hrs
after the burst (see
http://xmm.vilspa.esa.es/external/xmm_news/items/grb020321). Therefore,
we regard this detection as marginal. We would like to point out
another source which is outside the error circle of the marginal NFI
source but inside the WFC error circle of the burst (GCN 1281) and
which draws the attention through a comparison between the XMM-Newton
EPIC-pn image and the Chandra ACIS-S3 observation (a 5.5 hr exposure
starting 9.9 days after the burst; see Fox et al., GCN Circ. 1342). It
concerns source No. 2 in the EPIC-pn image which is located at
R.A. = 16h 12m 43.7s, Decl. = -83d 43' 13.9"
(equinox 2000.0; error 4"). This source 1) is 0.9' from the WFC
centroid; 2) shows a declining, though not smoothly, trend in the
EPIC-pn photon count rate (see aforementioned Vilspa web page); 3) is
the only EPIC-pn source covered but not detected in the ACIS-S3
image. Therefore, we propose that this is likely the X-ray afterglow
and urge optical and radio observers to concentrate on this position
for this 'dark' GRB.
We thank P. Rodrigues, N. Schartel and M. Santos at the XMM-Newton
Science Operations Centre (ESA) in Vilspa for advice on the XMM-Newton
data."
This message may be cited.
GCN Circular 1342
Subject
GRB 020321: Candidate X-ray Counterparts
Date
2002-04-08T23:44:03Z (24 years ago)
From
Derek Fox at CIT <derekfox@astro.caltech.edu>
D.W. Fox (Caltech) reports on behalf of the Caltech-NRAO-CARA GRB
collaboration:
"We have imaged the error circle of GRB020321 (GCN 1284, 1285) with
the Chandra X-ray Observatory for 20 ksec beginning at March 31.08 UT,
9.9 days after the burst. The pointing of the spacecraft was chosen
to center the 2-arcmin radius BeppoSAX NFI localization (GCN 1285) on
the ACIS-S3 detector. Reduction of the data using standard Ciao
procedures yields the following source catalog (listed in decreasing
order of significance) for this region:
ID IAU Name Sig Cts HR
=======================================================
1 CXOU J161122.3-834121 37.4 80.4(90) 0.47(12)
2 CXOU J161105.1-834111 15.1 31.5(57) 0.43(16)
3 CXOU J161104.2-834124 7.9 15.7(40) 0.12(16)
4 CXOU J161048.0-834004 3.0 5.8(25) 0.09(28)
5 CXOU J160953.5-834159 2.9 5.7(25) 0.63(89)
6 CXOU J161205.3-834132 2.5 4.8(22) 0.04(19)
7 CXOU J161058.8-834343 2.0 3.8(20) 0.52(65)
=======================================================
where "Sig" is the wavdetect-quoted significance of the source in the
0.3 to 7.0 keV band, "Cts" is the counts in this band over the 20.0 ks
exposure, "HR" is the hardness ratio of 2.1-7.0 keV counts to 0.3-2.1
keV counts, and uncertainties in the trailing digits are indicated in
parentheses. J2000 coordinates of the sources are implicit in their
IAU names.
No sources are detected coincident with the reported ATCA radio
candidates (GCN 1308). Source 6 (CXOU J161205.3-834132) is coincident
with a weak source (not a USNO star) from the Digitized Sky Survey
(SES)."
GCN Circular 1314
Subject
GRB 020321: Infrared observations
Date
2002-03-28T16:09:23Z (24 years ago)
From
Evert Rol at U.Amsterdam <evert@astro.uva.nl>
Evert Rol (Univ. of Amsterdam), Patrick Woudt (Univ. of Cape Town),
Isabel Salamanca, Lex Kaper (Univ. of Amsterdam), report on behalf of
a larger collaboration:
"We have observed the NFI errorbox of GRB 020321 (GCN 1281, 1842, 1285)
with the 1.4m Infrared Survey Facility telescope simultaneously in J,
H and K' band, at three epochs during the night of 21-22 March
2002. The log of the observations is as follows:
date exptime band
(days UT 2002) (seconds)
March 21.79 400 J, H, K'
March 21.95 400 J, H, K'
March 22.13 800 J, H, K'
We do not find any sources varying more than 3 sigma between the
different epochs, down to 3 sigma limiting magnitudes of 19.4 (J),
19.6 (H) and 18.9 (K').
In particular, we do not find any sources in the combined images at the
position of the two radio sources detected by ATCA (GCN 1308).
"
GCN Circular 1308
Subject
GRB 020321, Radio Observations
Date
2002-03-25T09:14:35Z (24 years ago)
From
Edo Berger at Caltech <ejb@astro.caltech.edu>
M. H. Wieringa (ATNF), E. Berger (Caltech), P. A. Price (Caltech and RSAA,
ANU), S. R. Kulkarni (Caltech) and D. A. Frail (NRAO) report:
"We observed the NFI error circle of GRB 020321 (GCN #1285) for 12 hours
centered on 2002, Mar 21.90 UT with the Australia Telescope Compact Array
(ATCA) at 4.8 and 8.7 GHz. At 8.7 GHz we detect two possible candidates
within the NFI error circle above a 5-sigma flux density of 190 microJy:
1. RA=16:11:14.2, DEC=-83:41:13.8 (J2000)
2. RA=16:11:27.8, DEC=-83:40:29.5 (J2000)
Further observations at both frequencies are required to establish
variability, and identify one of these sources as the radio afterglow of
GRB 020321.
We have also searched the positions of these radio candidates in the
Magellan/Baade 6.5-m telescope + LDSS2 data from 2002, Mar 22.28 and 23.41
UT (GCN 1305). We find no sources at these positions down to the limiting
magnitude of R~24 mag."
This message may be cited.
GCN Circular 1305
Subject
GRB 020321: Optical observations
Date
2002-03-24T03:45:24Z (24 years ago)
From
Paul Price at RSAA, ANU at CIT <pap@srl.caltech.edu>
P.A. Price (RSAA, ANU), A. Dressler and P. McCarthy (OCIW)
report on behalf of a larger collaboration:
We have observed the error circle of GRB 020321 (GCN #1285) with
the Magellan/Baade 6.5-m telescope + LDSS2 at 2002 Mar 22.28 and
23.41 UT. The limiting magnitude of our observations is
approximately R ~ 24 mag. We have performed PSF-matched image
subtraction to search for variable objects within the field. We do
not find any afterglow candidate upon visual inspection of the
subtracted image.
This message may be cited.
GCN Circular 1289
Subject
GRB 020321: Optical observations
Date
2002-03-22T00:54:03Z (24 years ago)
From
Paul Price at RSAA, ANU at CIT <pap@srl.caltech.edu>
P.A. Price (RSAA, ANU), B. Jones (Nottingham), B.A. Peterson (RSAA, ANU)
report on behalf of a larger collaboration:
We observed the refined error circle of GRB 020321 (GCN #1285) with the
SSO 40-inch telescope + WFI at 2002 Mar 21.62 UT in poor seeing
conditions. Our 2x600 sec observations in R band cover the entire error
circle to a limiting magnitude of R ~ 20.5 mag. We do not detect any
objects at the positions quoted by Henden & Nelson (GCN #1186). However,
we detect one object at coordinates
RA: 16:11:56.74 DEC: -83:39:57.3 J2000
(with approximate error of 0.5 arcsec) with R ~ 20 mag that does not
appear to be on the DSS-2 red plate. Further observations are required to
determine whether this source is the afterglow of GRB 020321.
This message may be cited.
GCN Circular 1286
Subject
GRB020321 optical observations
Date
2002-03-21T18:18:12Z (24 years ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
A. Henden and P. Nelson (Ellinbank Observatory, Australia)
on behalf of the AAVSO International GRB Network, report:
The Ellinbank 320mm f/5 Newtonian with an ST-8E CCD were used on 020321 UT
to image the BeppoSAX WFC error circle for GRB020321
(Gandolfi, GCN 1281; Guidorzi et al., GCN 1284).
A total of 30 x 30 sec images in Rc were taken from 12:22 to 12:47 UT
(8.2hrs after the burst), covering a 20x30 arcmin field that
includes the entire BeppoSAX error circle.
The ESO R and AAO R plate scans from the USNO PMM pixel database
were used to blink the resultant coadded image. The limiting
magnitude is estimated to be Rc=19. Two faint objects, near the
limiting magnitude, do not appear on the ESO or AAO plates, and
are not included in the minor planet database. These two objects
are at:
16:11:30.00 -83:39:12.1 J2000
16:12:52.00 -83:40:13.9
with position errors of about 0.5arcsec. These may be artifacts
of the processing, but are the only objects inside of the WFC error
circle that do not also appear on the photographic plates. In particular,
we find nothing new at our limiting magnitude inside the recent
NFI error circle (Gandolfi, GCN 1285).
The AAVSO would like to thank the Curry Foundation for supporting the
AAVSO International GRB Network.
GCN Circular 1285
Subject
GRB020321: BeppoSAX/NFI Observations
Date
2002-03-21T18:02:10Z (24 years ago)
From
Giangiacomo Gandolfi at IAS/CNR Frascati <gandolfi@ias.rm.cnr.it>
GRB020321: BeppoSAX/NFI Observations
A BeppoSAX TOO observation of GB020321 has started about 6
hours after the GRB.
A preliminary analysis of MECS(1.6-10 keV) image of the first orbits shows
a possible unknown source in the WFC error circle. The object, very faint,
seems to be fading.
The position is:
RA = 242.76
Delta = -83.70
The error radius is 2 arcminutes.
A more refined off-line analysys is required to confirm and improve the
detection.
G. Gandolfi
GCN Circular 1284
Subject
GRB020321: a faint BeppoSAX detection
Date
2002-03-21T16:39:35Z (24 years ago)
From
Cristiano Guidorzi at Phys.Dept, U.of Ferrara(Italy) <guidorzi@fe.infn.it>
C. Guidorzi, E. Montanari and F. Frontera, Universita' di Ferrara, L.
Amati, Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR, Bologna,
Marco Corsi and G. D'Andreta, BeppoSAX Science Operation Center (SOC),
Rome, Erik Kuulkers, Jean in 't Zand, Space Research Organization
Netherlands (SRON) and Astronomical Institute, Utrecht University, Paul
Lowes, SRON and SOC, L. Piro and G. Gandolfi, Istituto di Astrofisica
Spaziale e Fisica Cosmica, CNR, Rome.
"The BeppoSAX Gamma Ray Burst Monitor (GRBM) and the Wide Field Camera
(WFC) unit 1 detected GRB020321 on March 21.18102 UT. The GRB
was faint and has been discovered only by ground trigger logic.
The event detected by the GRBM shows an irregular single pulse profile
with a time duration of about 70 s and a peak count rate of 130+- 40 c/s,
as estimated with 1 s time resolution, in the 40-700 keV energy band.
In the WFC, the duration is about 1.5 min and the peak flux
is about 0.3 Crab (2-26 keV). The centroid position of the X-ray
counterpart from the WFC image is R.A. = 16h13m05s, Dec = -83d42'35"
(equinox 2000.0) with an error radius of 5' (99% CL).
A follow-up observation with BeppoSAX narrow-field instruments is in
progress."
This message is citable.
GCN Circular 1281
Subject
BeppoSAX ALERT: GRB020321, the "Springtime Burst"
Date
2002-03-21T10:54:37Z (24 years ago)
From
Giangiacomo Gandolfi at IAS/CNR Frascati <gandolfi@ias.rm.cnr.it>
BeppoSAX ALERT: GRB020321, the "Springtime Burst"
On Mar. 21, 04:20:40 UT a faint GRB (GRB020321) has been
detected in BeppoSAX WFC1
Refined coordinates are:
R.A.(2000)= 243.27
DEC.(2000)= -83.71
The error radius is 5', due to the non-optimal attitude configuration of
the satellite.
Giangiacomo Gandolfi
on behalf of
BeppoSAX Mission Scientist