GRB 050306
GCN Circular 3071
Subject
GRB 050306: Swift-BAT detection of a long burst
Date
2005-03-06T04:48:27Z (20 years ago)
From
Craig Markwardt at NASA/GSFC/UMD <craigm@milkyway.gsfc.nasa.gov>
C. Markwardt (GSFC/UMD), S. Barthelmy, L. Barbier, J. Cummings, (GSFC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD),
H. Krimm (GSFC/USRA), F. Marshall (GSFC), P. Meszaros (PSU), D. Palmer (LANL),
A. Parsons (GSFC), M. Perri (ASDC), T. Sakamoto (GSFC), G. Sato (ISAS),
M. Suzuki (Saitama), T. Takahashi (ISAS), J. Tueller, N. White (GSFC)
on behalf of the Swift-BAT team:
At 03:33:12 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB 050306. The burst location is 19 deg from the Moon,
and because of the Moon constraint, the spacecraft did not slew
to the burst location.
Using the time interval of the burst, the ground-calculated location
is RA,Dec 282.337,-9.162 (J2000) with an uncertainty of 3 arcmin
(radius, including a systematic uncertainty, 90% containment).
The burst was 51 degrees off the BAT boresight (19% encoding).
The burst lightcurve has 2 main peaks. At this time we have access
only to the TDRSS lightcuve which terminates at T+180 sec. The lightcurve
starts to rise again at T+165 sec indicating a possible 3rd peak.
The peak count rate is 2.4 counts/cm2/sec.
GCN Circular 3072
Subject
GRB 050306,optical observation
Date
2005-03-06T20:41:16Z (20 years ago)
From
Eri Sonoda at U of Miyazaki/Japan <sonoda@astro.miyazaki-u.ac.jp>
E.Sonoda,S.Maeno,Y.Matsuo,M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the error box of
GRB 050306 (GCN 3071 ; Swift-BAT Trigger time is 03:33:12 UT)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 18:13:46 UT on Mar.06.
Observed field of view is 43 arcmin centerd on
R.A=18h 49m 10s
Dec=-09d 06m 54s
After co-adding a set of 3 images of 30 sec exposures ,
we have compared with the USNO A2.0 and USNO B1.0 catalog.
Preliminary analysis shows there is no new source brighter than 17.5 mag. "
GCN Circular 3073
Subject
GRB 050306: TAROT optical observations
Date
2005-03-07T11:28:41Z (20 years ago)
From
Michel Boer at Obs Haute Prov. <Michel.Boer@oamp.fr>
Klotz, A., Boer M. (OHP), Atteia, J.L., and G. Stratta (LATT) report:
We imaged the entire field of GRB 050306 (cf. Markwardt et al. GCNC 3071)
with the TAROT robotic telescope (D=25cm) located at the Calern observatory,
France. Observations started 90 seconds after the begining of the burst.
The source was at an elevation of 15 degrees above the horizon. The Moon did
not rise during the observation, though the burst source location was 19 deg
from it. Nevertheless, haze was present, resulting in a loss of sensitivity.
No new source was detected after a comparison with the DSS2 R image.
We summarize below the limiting magnitude obtained by TAROT :
Beg. burst event 2005-03-06 03:33:12 UT (from GCNC 3071) End. burst event
2005-03-06 03:36:12 UT (from GCNC 3071)
Date from to Rmag Remarks
2005-03-06 03:35:19 03:35:49 >11 during prompt emission
2005-03-06 03:36:42 03:40:32 >13
2005-03-06 03:41:37 03:43:31 >14.4 6 min after the end of prompt emission
2005-03-06 03:44:32 03:45:40 >13
This message is citable.
GCN Circular 3075
Subject
GRB 050306: Possible X-ray Afterglow Position from the Swift
Date
2005-03-07T23:08:47Z (20 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
M. Perri, P. Giommi, M. Capalbi, F. Tamburelli (ASDC), P. Romano, D.
Malesani (INAF-OAB), V. Mangano, G. Cusumano, T. Mineo (INAF-IASF/Palermo),
D. N. Burrows, D. C. Morris, J. Kennea, M. Chester (PSU), K. L. Page, P. T.
O'Brien (U. Leicester), L. Angelini, N. Gehrels (GSFC), report on behalf
of the Swift XRT team:
GRB 050306 was within the Swift Moon avoidance angle until mid-day on 07
March 2005 (UT). Swift slewed to the BAT position (Markwardt et al. 2005,
GCN 3071) at about 14:55 UT on 07 March 2005 as a Target of Opportunity and
the XRT began observing it at 14:56:21 UT. Based on the first three orbits
of data (4218 s of data in Photon-Counting mode), we find two point sources
in our field of view, one of which is within the 3 arcminute radius BAT
error circle. This X-ray source is not present in any X-ray catalog and
its distance from the BAT position is ~105 arcsec. The coordinates of this
source are:
RA(J2000) = 18:49:14.0
Dec(J200) = -09:09:10.4
We estimate an uncertainty of about 6 arcseconds in this position.
We have only detected 12 photons from this source at this time and cannot
yet comment on whether it is fading. This source should be regarded as a
possible X-ray afterglow candidate. Further observations are in progress,
and these may allow us to make a more positive identification at a later date.
GCN Circular 3076
Subject
GRB 050306: REM optical-infrared observations
Date
2005-03-08T09:21:23Z (20 years ago)
From
Andrea Melandri at Rome Astro Obs <melandri@mporzio.astro.it>
A. Melandri, P. D'Avanzo, L. A. Antonelli, S. Covino, E. Palazzi,
G. Tagliaferri, G. Chincarini, F. M. Zerbi, G. Tosti, A. Monfardini,
N. Masetti, L. Nicastro, on behalf of the REM/ROSS team, report:
"On Mar 07, 2005 the field of GRB050306 (Markwardt et al. GCN 3071)
has been observed with the REM telescope located in La Silla (Chile).
The field was imaged with both REM instruments (REM-IR and ROSS) in
R, J, H and Ks filters starting at 8:28 UT (approximately 28.9 hours
after the burst). Total integration time was of 32, 84, 84 and 94
seconds respectively. A faster observation could not be performed
before due to the Moon proximity.
In the position of the possible X-ray afterglow candidate (Perri et
al. GCN 3075) no new source is clearly visible in our images.
Comparison with USNO B1.0 and 2MASS catalogues did not reveal new
sources down to a limiting magnitude of R > 17.0, J > 15.4, H > 15.2
and Ks > 15.0 (3-sigma upper limit).
This message can be cited."
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GCN Circular 3077
Subject
GRB 050306: No Swift UVOT Optical Counterpart Detected
Date
2005-03-08T12:41:47Z (20 years ago)
From
Pete Roming at PSU <roming@astro.psu.edu>
A. Blustin (MSSL), P. Brown (PSU), S. Rosen, K. McGowan, M. De Pasquale
(MSSL), 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), B. Hancock (MSSL), S. Koch (PSU), M. Carter, H. Huckle
(MSSL), P. Broos (PSU), T. Kennedy, P. Smith (MSSL), J. Nousek (PSU), N.
Gehrels (GSFC), on behalf of the Swift UVOT team.
The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of
GRB050128 (GCN 3071) on February 7, 2005 at 14:58:53 UT. Before this time
GRB 050306 was within the Swift Moon avoidance angle. Over an 8,630s
exposure combined from four snapshots between 35 and 41 hours after the
trigger, we detect no new or variable source down to a V magnitude of 21.2
(5-sigma upper limit) in the BAT error circle. This includes the position
of the X-ray candidate reported in GCN 3072.
GCN Circular 3078
Subject
GRB 050306: R-band observations
Date
2005-03-08T19:05:58Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
D. Fugazza, P. D'Avanzo, S. Covino (INAF-OABr), D. Malesani (SISSA), N.
Masetti, E. Palazzi (IASF-CNR), L.A. Antonelli (INAF-OARm), and G.
Andreuzzi (INAF-TNG), report on behalf of a larger Italian collaboration:
We observed the field of GRB 050306 (Markwardt et al., GCN 3071) with
the 3.6m TNG telescope, located in the Canary Islands. Observations were
carried out in the R and I bands, under moderate observing conditions
(high humidity, seeing ~1.5", airmass ~2). R-band observations started
on 2004 Mar 8.22 UT (2.07 days after the burst), and yielded 20 minutes
of net exposure.
Inside the 6-arcsec error circle of the candidate X-ray afterglow (Perri
et al., GCN 3075) we find several sources. Four of them are close to the
center (to within ~3"), while the remaining ones are right on the
border. All are fainter than the DSS limit. The large number of sources
is consistent with the crowding of this field lying towards the Galactic
plane.
At this stage, we are not able to single out any candidate afterglow.
Further observations are planned tonight in order to seek for variable
objects.
This message can be cited.
GCN Circular 3079
Subject
GRB 050306: CORRECTION to date of observation
Date
2005-03-08T20:00:52Z (20 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
A. Blustin (MSSL), P. Brown (PSU), S. Rosen, K. McGowan, M. De Pasquale
(MSSL), 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), B. Hancock (MSSL), S. Koch (PSU), M. Carter, H. Huckle
(MSSL), P. Broos (PSU), T. Kennedy, P. Smith (MSSL), J. Nousek (PSU), N.
Gehrels (GSFC), on behalf of the Swift UVOT team.
The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of
GRB050306 (GCN 3071) on March 7th, 2005 at 14:58:53 UT. Before this time
GRB 050306 was within the Swift Moon avoidance angle. Over an 8,630s
exposure combined from four snapshots between 35 and 41 hours after the
trigger, we detect no new or variable source down to a V magnitude of 21.2
(5-sigma upper limit) in the BAT error circle. This includes the position
of the X-ray candidate reported in GCN 3072.
GCN Circular 3084
Subject
GRB 050306: further TAROT optical data
Date
2005-03-10T17:46:14Z (20 years ago)
From
Michel Boer at Obs Haute Prov. <Michel.Boer@oamp.fr>
Klotz, A., Boer M. (OHP), Atteia, J.L., and G. Stratta (LATT) report:
We analyzed images taken 1 hour after GRB 050306 (cf. Markwardt et al. GCNC
3071) with the TAROT robotic telescope (D=25cm) located at the Calern
observatory, France. The source was at an elevation of 22 to 26 degrees
above the horizon but images are of good quality. We coadded 29 images of
30s with no filter. No new source was detected at the limiting magnitude
R~17.5 after a comparison with the DSS2 R and 2MASS images and the USNO-B1
catalogue. We summarize below the limiting magnitude obtained by TAROT:
Date from to Rmag Remarks
2005-03-06 04:18:54 04:53:02 >17.5 45 to 80 min after GRB
We also revised the limiting magnitude of the following measurement <e
published in GCNC 3073 :
Date from to Rmag Remarks
2005-03-06 03:41:37 03:43:31 >14.0 6 min after the end of prompt emission
We analyzed the 2MASS catalogue to extract the galactic extinction through
the line of sight of GRB050306. We used the method described in Klotz et al.
(A&A 2004, 425, p427). From Earth to a distance modulus of about 9.5-10.5,
the visual extinction is Av=2 +/-1. The 2MASS data don't allow probing farer
distances.
TAROT data for this GRB is summarized at the following URL:
http://www.cesr.fr/~klotz/grb050306/
This message is citable.
GCN Circular 3086
Subject
GRB 050306: Confirmation of X-ray afterglow
Date
2005-03-11T17:51:30Z (20 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
V. Mangano, G. Cusumano, T. Mineo (INAF-IASF/Palermo), M. Perri, P. Giommi,
M. Capalbi, F. Tamburelli (ASDC), D. N. Burrows, D. C. Morris, J. Hill, M.
Chester (PSU), A. Moretti, D. Malesani (INAF-OAB), O. Godet, P. T. O'Brien
(U. Leicester), L. Cominsky (Sonoma State U.), J. Greiner (MPE), D.
Hinshaw, and N. Gehrels (GSFC), report on behalf of the Swift XRT team:
The Swift X-Ray Telescope (XRT) observed the field of GRB 050306 (GCN
3071, Markwardt et al.) for a second time on 2005-03-10 from 01:08:09 UT
until 15:46:39 UT. We confirm that the source identified by Perri et al.
(GCN 3075) has faded from view and is therefore the likely X-ray afterglow
of this burst.
Only the Photon Counting mode, which provides the best XRT sensitivity, was
used for this observation. The total exposure time was 10205 s. No X-ray
emission was found from the XRT candidate afterglow detected on March 7
during the first XRT follow-up observation of the field (GCN 3075, Perri et
al.). We place a three sigma upper limit on the 0.5-10 keV count rate of
1.4e-3 cts/s which is significantly lower than the count rate observed on
March 7 (3.3e-3 cts/s), implying that the source has faded.
We conclude that the candidate reported in GCN 3075 is the X-ray afterglow
of GRB 050306. The updated position for this source is:
RA(J2000) = 18 49 14.1
Dec(J2000) = -09 09 11.2
This position is based on 12322s of data from March 7, 2005 (about 3 times
the amount used in our preliminary report in GCN 3075). The position
uncertainty is estimated to be about 6 arcseconds.
GCN Circular 3089
Subject
GRB 050306: optical afterglow
Date
2005-03-12T18:46:02Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
P. D'Avanzo, D. Fugazza, S. Covino (INAF-OABr), D. Malesani (SISSA), N.
Masetti, E. Palazzi (IASF-CNR), L.A. Antonelli, G.L. Israel (INAF-OARm),
and G. Andreuzzi (INAF-TNG), report on behalf of a larger Italian
collaboration:
We imaged again (Fugazza et al., GCN 3078) the field of GRB 050306
(Markwardt et al., GCN 3071) with the Italian TNG telescope.
Observations were carried out under a clear sky and with a seeing of
about 1.6", starting on 2005 Mar 9.247 UT. Seven R-band exposures were
acquired, with an overall exposure time of 21 minutes (mean UT Mar
9.260, i.e. 3.11 days after the burst).
Inside the revised error circle of the XRT afterglow (Perri et al., GCN
3075; Mangano et al., GCN 3086), we detect several sources. After
performing PSF photometry with DAOPhot, we find that the object at
coordinates:
alpha(J2000) = 18:49:13.95
delta(J2000) = -09:09:08.6
(that is, 3.5" off the XRT centroid position) has faded by 0.54+-0.10
mag since our previous observation, carried out ~2.1 days after the GRB
(Fugazza et al., GCN 3078). Assuming a powerlaw decay (F(t) =
K*t^-delta), this corresponds to delta = 1.28+-0.24, a value typical
among GRB afterglows at comparable epochs. We thus propose that this
object is the optical afterglow of GRB050603. Based on calibration upon
USNO stars, the object has R ~ 23 at the time of our first observation,
Mar 8.25 UT.
A finding chart of the field is posted at the following URL:
http://www.sissa.it/~malesani/GRB/050306
Further observations are planned at the TNG in the following nights, but
no spectroscopy will be possible.
We warmly acknowledge the TNG staff for carefully performing the
observations.
This message can be cited.
GCN Circular 3091
Subject
GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
Date
2005-03-12T23:05:51Z (20 years ago)
From
Frank Bertoldi at MPIFR/Bonn <bertoldi@mpifr-bonn.mpg.de>
F. Bertoldi (RAIUB Bonn), D.A. Frail (NRAO), A. Weiss (IRAM),
K.M. Menten (MPIfR Bonn), S. Kulkarni (Caltech), A. Soderberg
(Caltech) report:
We observed the position initially reported for the GRB 050306
X-ray afterglow by Perri et al. (GCN 3075), RA 18:49:14.0, Dec
-09:09:10.4 (J2000), with the Max-Planck-Millimeter Bolometer
(MAMBO-2) array at the IRAM 30-m telescope on
8 March 2005, between UT 8 and 9 h,
and obtained a non-detection of
S_nu(250 GHz,1.20mm) = 0.26 +/- 0.55 mJy
(1 sigma error). The MAMBO-2 bolometer detectors cover 210-290
GHz (half power). The likely optical afterglow reported by
D'Avanzo et al. (GCN 3089) is 1.9 arcsec from our pointing
position, and well within our 10.7 arcsec FWHM beam.
GCN Circular 3092
Subject
GRB 050306: Radio Observations
Date
2005-03-14T21:16:03Z (20 years ago)
From
Alicia Soderberg at Caltech <ams@astro.caltech.edu>
A. M. Soderberg (Caltech) and D. A. Frail (NRAO) report:
"Using the Very Large Array, we observed the field of
GRB 050306 (GCN 3071) at 8.5 GHz on Mar 14.42 UT. We detect
no source above our detection limit of 56 uJy (2-sigma)
within the XRT position (GCN 3086) which includes the location of
the optical afterglow candidate (GCN 3089)."
GCN Circular 3107
Subject
GRB 050306: ROTSE-III early limits
Date
2005-03-16T23:13:55Z (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, D. A. Smith and S. A. Yost
report on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded automatically to Swift GRB 050306 (Markwardt et al., GCN
3071) with the first 5-second exposure beginning Mar 6, 03:34:16.7 UT,
64.8 seconds after the burst. Comparison to the DSS (second epoch)
reveals no new sources, but we are limited by crowding in this low
galactic latitude field.
Using software provided by the Supernova Cosmology Project, we have
subtracted ROTSE-IIIc data obtained on Mar. 8 from our first Mar 6
image. No sources are detected on the subtracted frame within the
Swift XRT error circle (Perri et al., GCN 3075). In particular, we set
a 3-sigma upper limit on the magnitude of 15.8 (unfiltered, relative
to USNO A2.0) at the location of the TNG source (D'Avanzo et al., GCN
3089).
An extrapolation of a simple power-law with an index of 1.28 from the
TNG detection back to the epoch of our first image would predict a ~12
mag source. However, our non-detection is consistent with other
optical light curves that are underluminous at early times such as
GRBs 030418 and 030723 (Rykoff et al., 2004 ApJ 601,1013)
GCN Circular 3482
Subject
GRB050306: optical afterglow not confirmed
Date
2005-05-25T20:44:35Z (20 years ago)
From
Paolo D'Avanzo at INAF-OAB <davanzo@merate.mi.astro.it>
P. D'Avanzo, D. Fugazza, S. Covino (INAF-OABr), D. Malesani (SISSA), N.
Masetti, E. Palazzi (IASF-CNR), L.A. Antonelli, G.L. Israel (INAF-
OARm),
report on behalf of a larger Italian collaboration:
A detailed reanalysis of our images (Fugazza et al., GCN 3078; D'Avanzo
et al., GCN 3089) of the field of the Swift GRB 050306 (Markwardt et
al., GCN 3071; Perri et al., GCN 3075) does not allow to confirm the
variability of the candidate afterglow proposed in GCN 3089. At this
stage, no afterglow detection for this burst can be claimed from our
observations.
This message may be cited.