GRB 050319
GCN Circular 3116
Subject
GRB 050319: Detection of Possible Optical Counterpart
Date
2005-03-19T09:54:36Z (20 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E. Rykoff (Umich), B. Schaefer (LSU), R. Quimby (UTexas) report on
behalf of the ROTSE collagoration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
050319 (Swift 11162) in 9.2 s, 27 s after the burst. Our unfiltered
images detect a 16th magnitude, fading source at:
10:16:47.9 +43:32:54.5
Continuing observations are in progress. The object is at ~18th
magnitude, around 940 seconds after the burst.
GCN Circular 3117
Subject
Swift Detection of GRB 050319
Date
2005-03-19T10:42:25Z (20 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
Swift Detection of GRB 050319
H. Krimm (GSFC/USRA), M. Still (GSFC/USRA), S. Barthelmy, L. Barbier (GSFC),
S. Campana (INAF-OAB), M. Capalbi (ASDC), M. Chester (PSU),
J. Cummings (GSFC/NRC), E. Fenimore (LANL),
N. Gehrels (GSFC), M. R. Goad, O. Godet (U.Leicester), J. Greiner (MPE),
D. Grupe (PSU), D. Hullinger (GSFC/UMD), V. La Parola , V. Mangano
(INAF-IASF/Palermo),
C. Markwardt (GSFC/UMD), P. Meszaros, D. C. Morris,
J. A. Nousek (PSU), K. Page (U.Leicester), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama),
G.Tagliaferri (INAF-OAB),
J. Tueller (GSFC)
report on behalf of the Swift-BAT and Swift-XRT teams:
At 09:31:18.44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB 050319. The burst was 37 degrees off the BAT
boresight. The spacecraft executed an immediate slew and was on
target by 09:32:45.53 UT at which time the XRT began taking data in
Auto State. On-board software recognized a bright source at location
RA 154.2016d {+10h 16m 48s} (J2000),
Dec +43.5463d {+43d 32' 47"} (J2000)
We estimate an uncertainty of 7 arcseconds.
The burst lightcurve as seen in the BAT has a single peak with a fast
rise, exponential decay. The estimated duration is 15 seconds. The
peak count rate is 2,000 counts/second (15-350 KeV)
GCN Circular 3118
Subject
GRB050319,optical observation
Date
2005-03-19T16:02:58Z (20 years ago)
From
Shouta Maeno at U.of Miyazaki <shouta@astro.miyazaki-u.ac.jp>
S.Maeno,E.Sonoda,Y.Matsuo,M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the error box of
GRB 050319 (GCN 3117;Swift-BAT Trigger time is 09:31:18.44 UT)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 10:45:01 UT on Mar.19.
Observed field of view is 43 arcmin centerd on
R.A.=10h 17m 01s
Dec.=+43d 31m 06s
After co-adding a set of 9 images of 30 sec exposures,
we have compared with the USNO-A2.0 catalog.
Preliminary analysis shows there is no new source brighter than
17.8mag. at the reported position by GCN3116(E.Rykoff et al.) "
GCN Circular 3119
Subject
GRB 050319: Swift-BAT refined analysis
Date
2005-03-19T16:18:59Z (20 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
H. Krimm (GSFC/USRA), T. Sakamoto (GSFC/NRC), S. Barthelmy,
L. Barbier (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL),
N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), C. Markwardt (GSFC/UMD),
F. Marshall (GSFC), J. Nousek (PSU), D. Palmer (LANL), A. Parsons (GSFC),
G. Sato (ISAS), M. Still (GSFC/USRA), M. Suzuki (Saitama), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Analysis of the full data set for the Swift-BAT GRB 050319 (Krimm,
et al., GCN 3117) yields a fluence of 8 X 10^-7 erg/cm2 in the 15-350 keV
band and a peak flux of 1.7 ph/cm2/sec (also 15-350 keV). The photon index
of the 1-s peak spectrum ( starting at T0 +0.36 sec.) is 2.1 +- 0.3
(90% confidence). The time-averaged spectrum yields a photon index of
2.2 +- 0.2.
The overall measures of burst duration give T90 = 10 +- 2 seconds (including
systematics).
GCN Circular 3120
Subject
GRB 050319 : Confirmation of optical afterglow decay
Date
2005-03-19T16:42:37Z (20 years ago)
From
Yuji Urata at RIKEN <urata@crab.riken.go.jp>
GRB 050319 : Confirmation of optical afterglow decay
T. Yoshioka (Naogya Univ.), C.W. Chen (NCU), S.Nishiura (Tokyo Gakugei
Univ.), M. Isogai (Tokyo Univ.), T. Soyano(Tokyo Univ.), W.P. Chen (NCU)
Y. Urata, T. Tamagawa (RIKEN), K.Y. Huang, W.H. Ip (NCU), Y. Qiu (BAO)
and Y.Q. Lou(THCA)
on behalf of the East Asian collaboration report:
" We have observed the afterglow candidate of GRB 050319 (Rykoff et al.
# 3116, Krimm et al. # 3117) using Kiso 1.05-m and Lulin 1-m
telescopes starting at 2005 Mar. 19, 10:45 UTC (after end of
twilight). We have imaged the optical candidate (Rykoff et al. # 3116)
clearly in BVRI bands. Based on our preliminary photometry for R-band
images, we have confirmed the decay of the optical candidate.
Observation time and magnitudes are:
Filter Exposure UT Mag. site
R 300s 10:45 19.5 Kiso
R 300s 11:28 19.5 Lulin
R 300s 13:29 20.0 Kiso
Further observations are in progress, this message may be cite."
GCN Circular 3121
Subject
GRB 050319: Optical observation
Date
2005-03-19T17:30:56Z (20 years ago)
From
Ken ichi Torii at RIKEN <torii@crab.riken.go.jp>
K. Torii (Osaka U.) reports
"The error region of GRB 050319 (GCN 3117) was observed by the
ART 14-inch telescope. BVRcIc imaging started at 2005 March 19, 11:24
UT and 60-s exposure in each filter was repeated.
By stacking twenty Rc and twenty Ic frames obtained between 11:36 UT
and 13:05 UT (Mean Epoch 12:20 UT), we note an enhancement of
2.3-sigma level at the position of the optical afterglow (GCN
3116). The enhancement in the stacked frame corresponds to 19.6 mag
with reference to USNO-A2.0 red magnitude.
Combining this magnitude and those reported in GCN 3116 and GCN 3120,
the early optical afterglow of GRB 050319 decays with relatively
shallow power-law index of t^(-0.6)."
GCN Circular 3124
Subject
GRB050319: BR optical photometry
Date
2005-03-20T06:17:12Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
D. Sharapov, M. Ibrahimov, R. Karimov, B. Kahharov (UBAI), A.Pozanenko
(IKI), V.Rumyantsev (CrAO), G.Beskin (SAO) report:
We observed afterglow candidate of Swift GRB050319 (Rykoff et al. GCN
3116, Krimm et al. GCN 3117) with 1.5m telescope of Mt.Maidanak
high-altitude observatory. BR-band images were taken in two sets of
observation on (UT) March 19, 17:14 --17:58 and 19:18 -- 21:45. We confirm
a fading afterglow (Yoshioka et al. GCN 3120). Preliminary photometry
against of USNO-B1.0 Catalog is following:
Mean time Exposure Filter Mag.
(UT) (s)
Mar.19 17:28 900 B 20.85
Mar.19 17:31 1500 R 20.12
Mar.19 20:17 1800 B 21.29
Mar.19 20:16 4800 R 20.17
with typical magnitude error of less than 0.10.
B-R at the two epochs marginally indicate color variation which is not
typical for this phase of afterglow.
This message may be cited.
GCN Circular 3125
Subject
GRB 050319:Near IR afterglow
Date
2005-03-20T11:36:41Z (20 years ago)
From
Koshy George at PRL <koshyg@prl.ernet.in>
Koshy George,Jinesh Jain,N.M.Ashok,T.Chandrasekhar
(Physical Research Laboratory,India)
We report on the detection of near infrared afterglow of GRB 050319 using
NICMOS camera coupled with 1.2m telescope of Physical Research Laboratory
at Gurushikar, Mt.Abu, India.
The observations started at 15:41:00 UT on 19 March in J-band filter at
a 4'* 4' field of view shows a probable Infrared candidate at the error
region of optical afterglow candidate (GCN 3116 & 3117).
We had taken a net fourty minute exposure and the source which was present
in our first 20s frame was found to be faded down to our observational
limits with in 4min (four frames of each 60s exposure).
Preliminary analysis and on comparison with two near by stars present in
our field shows that the near infrared afterglow candidate corresponds to
a J-band magnitude ~ 13 at 15:41:20 UT
GCN Circular 3126
Subject
GRB 050319: NIR afterglow candidate
Date
2005-03-20T11:52:45Z (20 years ago)
From
Koshy George at PRL <koshyg@prl.ernet.in>
Koshy George, Jinesh Jain, N.M.Ashok, T.Chandrasekhar
(Physical Research Laboratory, India)
We report on the detection of near infrared afterglow of GRB 050319 using
NICMOS camera coupled with 1.2m telescope of Physical Research Laboratory
at Gurushikar, Mt.Abu, India.
The observations started at 15:41:00 UT on 19 March in J-band filter at
a 4'* 4' field of view shows a probable Infrared candidate at the error
region of optical afterglow candidate (GCN 3116 & 3117).
We had taken a net fourty minute exposure and the source which was present
in our first 20s frame was found to be faded down to our observational
limits with in 4min (four frames of each 60s exposure).
Preliminary analysis and on comparison with two near by stars present in
our field shows that the near infrared afterglow candidate corresponds to
a J-band magnitude ~ 13 at 15:41:20 UT
GCN Circular 3127
Subject
GRB050319: Radio Observations
Date
2005-03-20T18:10:48Z (20 years ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
A. M. Soderberg (Caltech) reports on behalf of the
Caltech-NRAO-Carnegie GRB collaboration:
"Using the Very Large Array at 8.5 GHz, we observed the
field of GRB050319 (GCN 3117) on 2005 Mar 20.03 UT.
We do not detect a radio source at the position of the optical
afterglow (GCN 3116). We place a (2-sigma) limit of 115 uJy.
Further observations are planned."
GCN Circular 3129
Subject
GRB 050319: Swift-UVOT detection of the afterglow
Date
2005-03-21T00:38:06Z (20 years ago)
From
Martin Still at NASA/GSFC Swift SSC <Martin.Still@gsfc.nasa.gov>
P. Boyd (GSFC/UMBC), S. T. Holland, M. Still (GSFC/USRA), W. Landsman
(GSFC), S. Hunsberger (PSU), A. Breeveld (MSSL), P. Roming (PSU), K.
Mason, P. Schady (MSSL), M. Ivanushkina (PSU), T. Poole (MSSL), C.
Gronwall (PSU) A. Blustin (MSSL), P. Brown (PSU), S. Rosen, K. McGowan
(MSSL), S. Koch (PSU), M. Carter, H. Huckle, M. De Pasquale (MSSL), P.
Broos (PSU), T. Kennedy, P. Smith, B. Hancock (MSSL), H. Krimm
(GSFC/USRA), J. Nousek (PSU), N. Gehrels (GSFC), on behalf of the Swift
UVOT team.
The Swift Ultra-Violet/Optical Telescope (UVOT) began
settled observations of the field of GRB 050319 (Krimm
et al; GCN 3117) at 09:32:48 UT, 90 after the BAT
trigger. A comparison of the 100s finding chart (with
mid-exposure 140s after the trigger) against the
Digitized Sky Survey reveals a new source inside the BAT
and XRT error circles at:
RA = 10h 16m 47.76(3)s Dec = +43d 32m 54.9(5)s J2000
and consistent with the ROTSE-IIIb position reported by
Rykoff et al. (GCN 3116) The V band magnitude is V =
17.5(1).
The UVOT obtained a series of images of this burst with
a variety of integration times. Mid-exposure times,
Delta-T, with respect to the BAT trigger at 09:31:18 UT
are measured in seconds. Observations with the V and B
filters are listed below:
Delta-T Exposure(s) Filter Mag
140 100 V 17.5 (Finding Chart)
380 80 B 18.8
600 80 V 18.4
1030 100 B 18.9
1250 100 V 19.2
5400 900 B 20.9
7080 700 V 20.2
17000 900 B 21.2
18700 700 V 20.6
No signal was detected in the U band in a total exposure
time of 90s centered approximately 600s after the
trigger with an upper limit of U = 19.
We caution that the absolute magnitude scale is based on
ground calibration and will require confirmation in
flight.
GCN Circular 3130
Subject
GRB 050319 R band observations
Date
2005-03-21T17:45:03Z (20 years ago)
From
Kuntal Mishra at State Obs,Nainital,India <kuntal@upso.ernet.in>
Kuntal Misra, Atish P. Kamble and S. B. Pandey (ARIES Naini Tal), on
behalf of larger Indian GRB collaboration
We observed the optical afterglow candidate (GCN 3116) localized by
Swift-BAT (GCN 3117) using the 1.04-m telescope at ARIES, Naini Tal
starting around 2005 March 19, 16:09 UT. We acquired BVRI images
under thin passing clouds. Our preliminary R-band photometry
gives a magnitude of 19.92 +/- 0.08 at 2005 March 19, 17:16 UT after
comparing with near by USNO-A2.0 stars. Further observations are in
progress.
This message may be cited.
GCN Circular 3131
Subject
GRB050319: radio observation
Date
2005-03-21T18:07:49Z (20 years ago)
From
Guy Pooley at MRAO, Cambridge, UK <ggp1@cam.ac.uk>
Guy Pooley (MRAO, Cavendish Astrophysics, Cambridge) reports:
Using the Ryle Telescope at 15 GHz in an observation of the field of
GRB050319 (GCN3117) centred on 2005 Mar 21.0, we do not detect
any radio emission; the formal measurement is 0.21 +- 0.23 (sigma)
at the position of the optical afterglow (GCN3116).
[GCN OPS NOTE (22mar05): Changed subject-line "090519" to "050319".]
GCN Circular 3132
Subject
GRB050319: VLA Observations
Date
2005-03-21T18:39:50Z (20 years ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
A. M. Soderberg (Caltech) reports on behalf of the
Caltech-NRAO-Carnegie GRB collaboration:
"Using the Very Large Array at 8.5 GHz, we observed again the
field of GRB050319 (GCN 3117) on 2005 Mar 21.4 UT.
We still do not detect a radio source at the position of the optical
afterglow (GCN 3116). We place a (2-sigma) limit of 133 uJy at
that position. Combining these data with those of our previous
epoch (GCN 3127), we derive a deeper limit of 70 uJy (2-sigma rms)
for the field."
GCN Circular 3135
Subject
GRB 050319: ROTSE-III Refined Analysis
Date
2005-03-22T02:19:44Z (20 years ago)
From
Robert Quimby at U of Texas/ROTSE <quimby@astro.as.utexas.edu>
R. M. Quimby, E. S. Rykoff, B. E. Schaefer, T. McKay, and S. A. Yost
report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at the McDonald Observatory, Texas, responded
automatically to Swift GRB 050319 (Krimm et al., GCN 3117, GCN 3119)
with the first 5-second exposure beginning Mar 19, 09:31:45.56 UT
(Rykoff et al., GCN 3116), 27.1 seconds after the BAT trigger. The
observing sequence consisted of ten 5-second and ten 20-second images
followed by about 70 60-second exposures before clouds set in. All
images are unfiltered and the average time between exposures was 9.5
seconds.
We measured the afterglow flux in circular apertures relative to our
deepest image, and calibrated the magnitude scale by adopting SDSS
r-band values for our fiducial reference stars. Magnitudes on this
system for our first 5, 20, and 60-second images are given below.
Time (UT) mag +/-
09:31:45.56 16.16 0.17
09:34:09.95 17.22 0.20
09:39:05.24 17.58 0.18
The afterglow is detected in the first 30 images, and coadding the
later exposures in groups of 5 to 10 also results in detections,
making this one of the best sampled early light curves for any
GRB. The afterglow is well fit by a t^(-alpha) power law with
alpha=0.59 +/- 0.05, consistent with later R band observations
reported in the GCN Circulars (GCNs 3120, 3121, 3124). Continuing this
trend predicts the afterglow is currently brighter than 22nd
magnitude.
No host is present in the SDSS data at the location of the afterglow,
which implies the redshift for this GRB is larger than 0.3. We also
note the IR detection reported by George et al. (GCN 3125) gives a J-R
color of about 7, and could suggest a high-z source. Spectral
observations are encouraged to accurately determine the GRB redshift.
GCN Circular 3136
Subject
GRB 050319: Absorption redshift from the Nordic Optical Telescope
Date
2005-03-22T09:08:13Z (20 years ago)
From
Johan U. Fynbo at U.Copenhagen <jfynbo@astro.ku.dk>
GRB 050319: Absorption redshift from the Nordic Optical Telescope
Johan P. U. Fynbo, Jens Hjorth, Brian L. Jensen, Pall Jakobsson
(Niels Bohr Institute), Palle Moller (ESO), Jyri N�r�nen (Nordic
Optical Telescope) report:
"Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained
spectra of the afterglow of GRB 050319 (GCN 3116, 3117) on 2005,
March 20 UT. We find several absorption features, including strong
Lyman-alpha, OI+SiII, SiIV and CIV, corresponding to a redshift of
z=3.24."
GCN Circular 3139
Subject
GRB050319: RTT150 Optical Observations
Date
2005-03-23T08:22:43Z (20 years ago)
From
Umit Kiziloglu at Middle East Tech.U,Phys.Dept <umk@astroa.physics.metu.edu.tr>
U. Kiziloglu, S. Balman, A. Baykal (METU), Z. Aslan, I. Khamitov,
K. Uluc (TUG), S. Evren (EgeU), A. Alpar (Sabanci U.), R. Burenin,
M. Pavlinsky (IKI), R. Sunyaev (IKI, MPA), I, Bikmaev (KSU) report :
We observed the field centered on the Swift GRB 041006 (Rykoff et al.
GCN 3116, Krimm et al., GCN 3117, GCN 3119) with the TUG (TUBITAK
National Observatory, Turkey) 1.5-m Russian-Turkish Telescope (RTT150).
We obtained 8x300s 6x120s 3x60s R band images on 2005.03.19 starting
at 17:26:36 UT using the imaging ANDOR CCD. The seeing was 1.8"-2.1".
We further obtained 6x300 s R band images on 2005.03.20 and 2005.03.21
with RTT150. The seeing was poor with Moon.
We calculated the R magnitudes below using the USNO B1.0 Catalog.
Observation (UT) R_mag
-------------------- ----------------------
2005 March 19, 18:12 20.14 +/- 0.09
2005 March 21, 00:16 21.3 +/- 0.6 1 Sigma frame upper limit
2005 March 21, 17:58 21.1 +/- 0.3
This message can be cited.
GCN Circular 3140
Subject
GRB050319: optical observation, March 20-22
Date
2005-03-24T14:36:37Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
D. Sharapov, M. Ibrahimov, R. Karimov, B. Kahharov (UBAI), A.Pozanenko
(IKI), V.Rumyantsev (CrAO), G.Beskin (SAO) report:
We continue observation (Sharapov et al. GCN 3124) of GRB050319 afterglow
(Rykoff et al. GCN 3116, Krimm et al. GCN 3117) with 1.5m telescope of
Maidanak Astronomical Observatory, Mt.Maidanak, Uzbekistan. R-band images
were taken in several sets of observation on March 19-22. Preliminary
photometry against of USNO-B1.0 Catalog is following:
Mean time Exposure Filter Mag.
(UT) (s)
Mar.20 21:49 2640 R 21.62 (0.07)
Mar.21 21:34 1560 R 21.67 (0.09)
Mar.22 18:41 1260 R 21.27 (0.13)
Observations obtained on March 22 are not compatible with power law index
decay 1.59 (.05) for early and first day afterglow observations (Torii et
al. GCN 3132, Quimby, GCN 3135) suggesting a presence of knee or
re-brightening of the afterglow light curve.
Excellent seeing conditions during the observations on Mar. 22 (~0.7") allow
us to investigate some details of the field objects. In particular IDs
(USNO-B1.0) 1335-0213759 and 1335-0213777 seem to be galaxies, and ID
1335-0213724 is a variable star. All above is leaving a few field stars for
calibration.
Deep field photometry for correct calibration would be encouraged.
This message may be cited.
GCN Circular 3141
Subject
GRB050319, color indices
Date
2005-03-25T10:50:15Z (20 years ago)
From
Rene Hudec at AIO <rhudec@asu.cas.cz>
This is a multi-part message in MIME format.
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<> V. Simon, R. Hudec (Astronomical Institute AV CR, Ondrejov, Czech
Republic) and G. Pizzichini, N. Masetti (INAF/IASF Bologna, Italy) report:
<>
We have determined the color indices of the optical afterglow (OA) of
GRB050319 in its very early phase from the available data (GCN 3124,
3129). The interpolation method described in Simon et al. (2001, A&A,
377, 450) was used. Since the Swift UVOT magnitudes need a confirmation
of their calibration, we determined the indices separately for UVOT and
ground-based observations. The indices of the OA from UVOT are:
t-To=0.0044 d: B-V=0.68; 0.0119: -0.10; 0.0625: 0.85; 0.1968: 0.64,
while those of the ground-based observations (GCN 3124) are: t-To(d)=
0.331 d: B-R=0.73; 0.448: 1.12. The typical error of these indices is
about 0.10 mag.
The Galactic reddening E(B-V)=0.011, determined from the maps by
Schlegel et al. (1998, ApJ, 500, 525), is comparable to the errors
of the measurements.
We note that the variations in B-V, with a peak at t-To=0.01 days,
are caused by a plateau in B while the V magnitude was already
steadily decreasing. The last two measurements from UVOT can
suggest that B-V reached the value roughly consistent with the
typical one for the ensemble of 23 OAs, defined by Simon et al.
(2001; 2004, AIP Conf. Proc., Vol.727, p.487), not later than at
t-To=0.06 days.
The indices of the OA of GRB050319 for t-To > 0.06 days thus appear
to be plausibly consistent with the mean values of the ensemble
(B-V)o=0.45+/-0.15, (B-R)o=0.86+/-0.17. This suggests that the shape
of the spectrum of the afterglow of GRB050319 is similar to the other
afterglows and that its intrinsic reddening (that is inside the host
galaxy) must be again small (Simon et al. 2001; 2004, AIP Conf.
Proc., Vol.727, p.487). Also the redshift of GRB050319 z=3.24 (GCN
3136) suggests that this GRB appears to be another member of the
above-mentioned ensemble of the OAs with z < 3.5.
The search for the host galaxy and the determination of its type
are also encouraged.
This message may be cited.
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<pre style="text-align: justify;"><tt>
<o:p></o:p></tt></pre>
<tt><> V. Simon, R. Hudec (Astronomical Institute AV CR, Ondrejov,
Czech <o:p></o:p></></tt>
<pre style="text-align: justify;"><tt>Republic) and G. Pizzichini, N. Masetti (INAF/IASF Bologna, Italy) report:
<o:p></o:p></tt></pre>
<tt><><span style=""><br>
</span><o:p></o:p>We have determined the color indices of the optical
afterglow (OA) of <o:p></o:p></></tt>
<pre style="text-align: justify;"><tt>GRB050319 in its very early phase from the available data (GCN 3124, <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>3129). The interpolation method described in Simon et al. (2001, A&A, <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>377, 450) was used. Since the Swift UVOT magnitudes need a confirmation <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>of their calibration, we determined the indices separately for UVOT and <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>ground-based observations. The indices of the OA from UVOT are: <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>t-To=0.0044 d: B-V=0.68; 0.0119: -0.10; 0.0625: 0.85; 0.1968: 0.64, <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>while those of the ground-based observations (GCN 3124) are: t-To(d)=<o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>0.331 d: B-R=0.73; 0.448: 1.12. The typical error of these indices is <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>about 0.10 mag. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt><o:p> </o:p></tt></pre>
<pre style="text-align: justify;"><tt>The Galactic reddening E(B-V)=0.011, determined from the maps by <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>Schlegel et al. (1998, ApJ, 500, 525), is comparable to the errors <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>of the measurements. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt><span style=""> </span><o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>We note that the variations in B-V, with a peak at t-To=0.01 days, <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>are caused by a plateau in B while the V magnitude was already <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>steadily decreasing. The last two measurements from UVOT can <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>suggest that B-V reached the value roughly consistent with the <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>typical one for the ensemble of 23 OAs, defined by Simon et al. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>(2001; 2004, AIP Conf. Proc., Vol.727, p.487), not later than at <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>t-To=0.06 days.<o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt> <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>The indices of the OA of GRB050319 for t-To > 0.06 days thus appear <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>to be plausibly consistent with the mean values of the ensemble <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>(B-V)o=0.45+/-0.15, (B-R)o=0.86+/-0.17. This suggests that the shape <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>of the spectrum of the afterglow of GRB050319 is similar to the other <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>afterglows and that its intrinsic reddening (that is inside the host <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>galaxy) must be again small (Simon et al. 2001; 2004, AIP Conf. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>Proc., Vol.727, p.487). Also the redshift of GRB050319 z=3.24 (GCN <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>3136) suggests that this GRB appears to be another member of the <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>above-mentioned ensemble of the OAs with z < 3.5. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>The search for the host galaxy and the determination of its type <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>are also encouraged. <o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt><span style=""> </span><o:p></o:p></tt></pre>
<pre style="text-align: justify;"><tt>This message may be cited.</tt><o:p></o:p></pre>
<pre style="text-align: justify;"> <o:p></o:p></pre>
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begin:vcard
fn:Rene Hudec
n:Hudec;Rene
org:Astronomical Institute, CZ-251 65 Ondrejov, Czech Republic;High Energy Astrophysics Group
adr:;;Observatory Ondrejov;Ondrejov;;CZ-251 65;Czech Republic
email;internet:rhudec@asu.cas.cz
tel;work:00420 323 620128
tel;fax:00420 323 620263
tel;home:00420 323 649011
tel;cell:00420 737 137396
url:http://www.asu.cas.cz
version:2.1
end:vcard
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GCN Circular 3142
Subject
GRB050319, optical observations
Date
2005-03-25T18:14:38Z (20 years ago)
From
Adalberto Piccioni at Astronomy, Bologna U. <piccioni@ermione.bo.astro.it>
G. Greco, C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University),
P. Ferrero (Osservatorio e Universita' di Teramo), G. Pizzichini (IASF-CNR,
Sezione di Bologna) and I. Bruni (Osservatorio di Bologna) report:
We observed the error box of GRB050319 (SWIFT trigger 11162; Krimm et al.,
GCN 3117) in Rc light on March 20 in good sky conditions (seeing approx.
1.5 - 2 arcsec) but in presence of high contribution of moonlight with
the 152 cm G.D. Cassini telescope of Bologna University, equipped with the
BFOSC CCD imager.
We got 4X1200s images with the following results:
UT at start exposure Exposure (s) OT Rc mag
2005 March 20, 2:14 1200 19.58 (+- 0.18)
2005 March 20, 2:37 1200 19.66 (+- 0.16)
2005 March 20, 3:02 1200 19.67 (+- 0.16)
2005 March 20 3:25 1200 19.69 (+- 0.19)
obtained using as comparisons the following objects extracted from
the USNO A2 catalog:
ID: 1275-07685084
ID: 1275-07684473
ID: 1275-07683651
ID: 1275-07685059
ID: 1275-07684793
ID: 1275-07685268
ID: 1275-07684751
From our images, by comparison with the R magnitudes reported by CGN 3124,
3139 and 3140 we infer a substantial rebrightening. An image of the OT
is posted
into a public directory from where it can be retrieved by sftp using
hostname: ermione.bo.astro.it, username: publicGRB, password: GRB_bo and
directory: GRB050319.
GCN Circular 3153
Subject
GRB050319: radio observation
Date
2005-03-28T16:09:53Z (20 years ago)
From
Vasilij Rumjantsev at CrAO <rum@crao.crimea.ua>
A.Volvach (CrAO), A.Pozanenko (IKI) reports on behalf of CrAO-IKI-SAO GRB
collaboration:
We observed the error-box of GRB050319 (Krimm et al. GCN 3117) on March 21,
and 24 at 2.3 GHz and 8.4 GHz with RT-22 of Crimean Astrophysical
Observatory.
Upper limits obtained for the afterglow position (Rykoff et al. GCN 3116)
are approximately equal for both 2.3 GHz and 8.4 GHz frequencies:
Mar. 21.69 (UT) 2 mJy (2 sigma)
Mar. 24.67 (UT) 2 mJy (2 sigma)
Results of observations are in an agreement with GCN 3132 (A. M. Soderberg)
This message may be cited.