GRB 080330
GCN Circular 7536
Subject
GRB 080330: TAROT Calern observatory optical detection
Date
2008-03-30T04:02:13Z (17 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 080330 detected by SWIFT
(trigger 308041) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
The observations started 20.4s after the GRB trigger
(4.5s after the notice). The elevation of the field decreased from
from 26 degrees above horizon and weather conditions
were good.
We detect a new raising source in the error box given by SWIFT
We detected the candidate couterpart in the XRT location
at the following position (+/- 1 arcsec):
RA(J2000.0) = 11h 17m 04s47
DEC(J2000.0) +30d 37' 26"90
OT was R~16.8 at 300s after GRB.
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon=197.8461 lat=+69.1207
and the galactic extinction in R band is 0.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.
This me
GCN Circular 7537
Subject
GRB 080330: Swift detection of a burst with an optical counterpart
Date
2008-03-30T04:02:22Z (17 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
J. Mao (INAF-OAB), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), K. M. McLean (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), T. N. Ukwatta (GSFC/GWU) and
D. E. Vanden Berk (PSU) report on behalf of the Swift Team:
At 03:41:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080330 (trigger=308041). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 169.302, +30.570 which is
RA(J2000) = 11h 17m 12s
Dec(J2000) = +30d 34' 13"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multiple-peak
structure with a duration of about 60 sec. The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 03:42:27.4 UT, 70.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 169.26095,
30.62298 which is equivalent to:
RA(J2000) = 11h 17m 2.63s
Dec(J2000) = +30d 37' 22.7"
with an uncertainty of 3.077 arcseconds (radius, 90% containment). This
location is 229 arcseconds from the BAT onboard position, outside the
BAT error circle.
A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density, so we cannot provide limits
on the redshift using spectroscopy and the relation from Grupe et al.
(2007). A summary of the promptly downlinked data is given at
http://www.swift.ac.uk/sper/308041/.
The initial flux in the 2.5 s image was 2.03e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of nominal 100 seconds with the White
(160-650 nm) filter starting 82 seconds after the BAT trigger. There is a
candidate afterglow in the list of sources generated on-board at
RA(J2000) = 11:17:04.51 = 169.2688
DEC(J2000) = +30:37:22.1 = 30.6228
with a 1-sigma error radius of about 1.0 arc sec. This position is 6.1 arc sec.
from the center of the XRT error circle. The estimated magnitude is 18.8 with a
1-sigma error of about 0.5 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is J. Mao (jirong.mao AT brera.inaf.it).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular 7539
Subject
GRB 080330: Liverpool Telescope Optical observations
Date
2008-03-30T04:21:17Z (17 years ago)
From
Andreja Gomboc at LT,ARI,Liverpool JMU <ag@astro.livjm.ac.uk>
A. Gomboc (University of Ljubljana), C. Guidorzi (U. Bicocca & INAF-OAB),
A. Melandri, C. G. Mundell, A. Monfardini, R.J. Smith, I.A. Steele,D.
Bersier, S. Kobayashi, M. Burgdorf, D. Carter (Liverpool JMU) report:
The 2-m Liverpool Telescope reacted robotically to GRB 080330 (Swift
trigger 308041) starting 3 min after the GRB trigger time. We detect
initially rising and subsequently fading optical candidate in r', i' and
g' filters at the posotion consistent with XRT source, UVOT (Mao et al.,
GCN 7537) and TAROT optical candidate (Klotz, Boer & Atteia, GCN 7536).
The magnitude of the source in first frames is r'=17.3 +-0.1.
GCN Circular 7540
Subject
GRB080330 - SDSS Pre-Burst Observations
Date
2008-03-30T04:24:11Z (17 years ago)
From
Richard J. Cool at U.of AZ/Steward Obs <rcool@as.arizona.edu>
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona),
David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel
(LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald
P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst
GRB080330 prior to the burst. As these data should be useful
as a pre-burst comparison and for calibrating photometry,
we are supplying the images and photometry measurements for
this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and
3 files of photometry and astrometry, are being placed at
http://mizar.as.arizona.edu/~grb/public/GRB080330
We supply FITS images in each of the 5 SDSS bands of a 8'x8'
region centered on the GRB position (ra=169.302 (11:17:12.5),
dec=30.5700 (30:34:12.0); Swift-BAT 308041), as well as 3 gri
color-composite JPGs (with different stretches). The units
in the FITS images are nanomaggies per pixel. A pixel is
0.396 arcsec on a side. A nanomaggie is a flux-density unit
equal to 10^-9 of a magnitude 0 source or, to the extent that
SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS
astrometric information.
In the file GRB080330_sdss.calstar.dat, we report photometry
and astrometry of 219 bright stars (r<20.5) within 15' of the
burst location. The magnitudes presented in this file are asinh
magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118,
1406). Beware that some of these stars are not well-detected
in the u-band; use the errors and object flags to monitor
data quality.
In the files GRB080330_sdss.objects_flux.dat and
GRB080330_sdss.objects_magnitudes.dat, we report photometry
of 1512 objects detected within 6' of the GRB position.
We have removed saturated objects and objects with model
magnitudes fainter than 23.0 in the r-band. The fluxes listed
in GRB080330_sdss.objects_flux.dat are in nanomaggies while
the magnitudes listed in GRB080330_sdss.objects_magnitudes.dat
are asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning
that they are very close to AB zeropoints and magnitudes are
quoted in asinh magnitudes. Photometric zeropoints are known
to about 2% rms. None of the photometry is corrected for
dust extinction. The Schlegel, Finkbeiner, and Davis (1998)
predictions for this region are A_U=0.082 mag, A_g=0.060 mag,
A_r = 0.044 mag, A_i=0.033 mag, and A_z=0.023 mag.
The file GRB080330_sdss.spectro.dat contains a list of the
2 objects with SDSS spectroscopy within 6 arcminutes of the
GRB position. In addition to the redshift and 1-sigma error
for each object, this file also lists the object spectroscopic
classification.
SDSS astrometry is generally better than 0.1 arcsecond per
coordinate. Users requiring high precision astrometry should
take note that the SDSS astrometric system can differ from
other systems such as those used in other notices; we have
not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases
can be found in our initial data release paper (Cool et
al. 2006, PASP 118, 733). See the SDSS DR4 documentation for
more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different
pipeline than that used for SDSS public data releases.
We cannot guarantee that the values here will exactly match
those in the data release in which these data are included.
In particular, we expect the photometric calibrations to differ
by of order 0.01 mag.
This note may be cited, but please also cite the SDSS data
release paper, Adelman-McCarthy et al. (2007, ApJS, 172, 634),
when using the data or referring to the technical documentation.
GCN Circular 7541
Subject
GRB 080330: error in reported XRT position
Date
2008-03-30T04:36:19Z (17 years ago)
From
David Burrows at PSU/Swift <dnburrows@gmail.com>
D. N. Burrows (PSU) reports on behalf of the Swift XRT team:
The XRT position for GRB 080330 that was distributed in GCN Circ.
7537 was incorrect. The initial on-board XRT position determined
immediately after the spacecraft slew was
GRB_RA: 169.2707d {+11h 17m 04.9s} (J2000),
GRB_DEC: +30.6223d {+30d 37' 20.2"} (J2000),
with a nominal error circle radius of 5.0 arcseconds. This position
was 6.1 arcseconds from the UVOT position. It appears that shortly
after arriving on-target, the spacecraft began slowly drifting
because the star tracker did not lock properly on the star
field. The updated XRT position based on promptly downloaded data
was determined using inaccurate aspect information from the satellite
and was therefore incorrect. We apologize for any confusion that
this may have caused. We reiterate that the XRT position appears to
be consistent with the optical position.
GCN Circular 7543
Subject
GRB 080330: TAROT Calern observatory optical observations
Date
2008-03-30T06:31:40Z (17 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:
We complete the TAROT analysis of GRB 080330 detected by SWIFT
(trigger 308041) at the location of the rising afterglow
detected by Klotz et al. (GCNC 7536). We refined the
coordinates (better than 1 arcsec) :
RA(J2000.0) = 11h 17m 04s49
DEC(J2000.0) +30d 37' 23"5
We consider the date of trigger : t0 = 2008-03-30T03:41:17
The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect the OT with a limiting magnitude of:
t0+20.4s to t0+80.4s : R > 17.0
This limiting magnitude is compatible with the detection
R~17.5 by ROTSE-IIIb (Schaefer et Guver GCNC 7538) at
~t0+25s.
The later images, in tracking mode, show the afterglow.
We measured the alpha index considering flat flux is
proportional to t^-alpha:
t0+ 88s to t0+ 332s : alpha=-0.8 (rise)
t0+332s to t0+ 428s : maximum of brightness R~16.8
t0+428s to t0+1068s : alpha=+0.4 (decay)
t0+1068s : R~17.2
Two images were taken between t0+1177s
and t0+1363s during the dawn. They seem to show
a plateau or even a rebrightening.
Observations are now stoped at Calern.
This message may be cited.
GCN Circular 7544
Subject
GRB 080330: NOT redshift
Date
2008-03-30T07:19:56Z (17 years ago)
From
Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center <malesani@astro.ku.dk>
Daniele Malesani, Johan P.U. Fynbo (DARK), Pall Jakobsson (Univ.
Hertfordshire), Paul M. Vreeswijk (DARK), Sami-Matias Niemi (NOT),
report on behalf of a larger observation:
We observed the afterglow of GRB 080330 (Mao et al., GCN 7537) with the
NOT equipped with ALFOSC. We clealy detect the optical counterpart
(Klotz et al., GCN 7536; Mao et al., GCN 7537, Schaefer & Guver, GCN
7538; Gomboc et al., GCN 7539; Bloom & Starr, GCN 7542). We measure R =
17.55 on March 30.17596 UT (32.1 min after the GRB), assuming R = 17.61
for the USNO star 1206-0188558 at RA = 11:16:57.541, Dec = +30:37:51.51.
A 1800 s spectrum with ALFOSC was acquired starting 46 min after the
GRB, covering the range 3700-8000 AA. A preliminary reduction of the
data reveals absorption features in the spectrum from C IV, Zn II, Fe
II, and Mg II at redshift z=1.51.
We acknowledge excellent support from the NOT staff
GCN Circular 7545
Subject
GRB 080330: GROND Observations
Date
2008-03-30T10:06:42Z (17 years ago)
From
Christian Clemens at MPE <cclemens@mpe.mpg.de>
C. Clemens, A. Kupcu Yoldas, J. Greiner, A. Yoldas, T. Kruehler (all MPE
Garching) and G. Szokoly (Eoetvoes Univ., Budapest and MPE Garching) report
on behalf of the GROND team:
We observed the field of GRB 080330 (Swift trigger 308041; Mao et al., GCN
#7537) simultaneously in g', r', i', z', J, H and K with GROND (Greiner et
al. 2008, PASP) mounted at the 2.2m ESO/MPI telescope at La Silla Observatory
(Chile).
Observations started at 03:44:23 UT on March, 30th, 2008, about 3.1 mins after
the GRB trigger. We found a bright point source at
RA (J2000.0) = 11h 17m 04.48s
DEC (J2000.0) = 30d 37' 24.4'',
coincident with the optical afterglow first reported by Klotz et al. (GCN
#7536 and #7543).
Based on the first 240 s of effective exposures in J and H, we estimate
magnitudes of
J=15.92 +/- 0.02 and H=15.45 +/- 0.01,
calibrated against 2MASS stars.
GCN Circular 7546
Subject
GRB080330: LOAO R-band Detection
Date
2008-03-30T12:06:18Z (17 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, I. Lee (Seoul National Univ.), Y. Urata (Saitama U/ASIAA),
J.W. Lee, J. Yoon, S.-L. Kim, C.-U. Lee (KASI), on behalf of EAFON team.
We took R-band images of GRB080330 (Hao et al. GCN 7537)
using the 1.0m telescope at Mt. Lemmon (Arizona, US)
operated by the Korea Astronomy Space Science Institute.
The R-band imaging started at March 30, 06:57:55.1 UT
(3:15:56 after the burst).
We clearly detect the afterglow at the location reported by
Schaefer et al. (GCN 7538).
Start time Mid-point Rmag
-------------------------------------------------------------
06:57:55.1 07:11:50.4 19.63 +- 0.05
(3hr15m after burst) (3hr30m after burst)
The magnitude is calibrated with a GSC2.2 star at
(11:16:56.54, +30:37:51.4).
The afterglow faded by more than 2 magnitudes since the
detections shoftly after the burst (GCN 7536, 7538, 7543).
This message may be cited.
GCN Circular 7547
Subject
GRB 080330: Redshift Confirmation from Hobby-Eberly Telescope Spectroscopy
Date
2008-03-30T15:21:39Z (17 years ago)
From
Antonino Cucchiara at PSU <cucchiara@astro.psu.edu>
A. Cucchiara & D. B. Fox (PSU) report on behalf of a larger
collaboration:
"Starting on 2008 March 30.35 UT we used the Marcario LRS spectrograph
on the Hobby-Eberly Telescope (R ~ 230 ) to obtain 2 x 1000s spectra
of the optical afterglow (Mao et al., GCN 7537) of GRB 080330. The
spectrum covers the wavelength range 4100 to 10,500 Angstrom. We
observe multiple metal absorption features including the MgII doublet
(2796, 2803 A) and MgI (2852 A), FeII (2586, 2600 A), ZnII (2026 A)
and NiII (1741,1751 A) at redshift z = 1.51. Our observations are
consistent with the redshift and features reported by Malesani et
al. (GCN 7544)."
GCN Circular 7549
Subject
GRB 080330, Swift-BAT refined analysis
Date
2008-03-30T16:39:37Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
J. Mao (INAF-OAB), K. McLean (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080330 (trigger #308041)
(Mao, et al., GCN Circ. 7537). The BAT ground-calculated position is
RA, Dec = 169.278, 30.607 deg, which is
RA(J2000) = 11h 17m 06.7s
Dec(J2000) = +30d 36' 24.1"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 53%.
The mask-weighted light curve shows an initial set of 3 overlapping peaks
(the brightest first) starting at ~T_zero, and the 3rd ending at ~T+15 sec,
then it returns to baseline. A 4th peak starts at roughly T+50 sec and
ends at roughly T+70 sec. T90 (15-350 keV) is 61 +- 9 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.5 to T+71.9 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.53 +- 0.45. The fluence in the 15-150 keV band is 3.4 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.44 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/308041/BA/
We note that the fluence ratio in a simple power-law fit between the
25-50 keV band and the 50-100 keV band is 1.44. This fluence ratio is larger
than 1.32 which can be achieved in the Band function of alpha=-1.0, beta=-2.5,
and Epeak=30 keV. Thus, preliminary analysis shows that Epeak of the burst
is very likely around or below 30 keV. Therefore the burst can be classified
as an X-ray flash (e.g. Sakamoto et al. ApJ in press, arXiv:0801.4319).
GCN Circular 7550
Subject
GRB080330: TNT optical observations
Date
2008-03-30T16:49:47Z (17 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
X.F.Wang, J.Z.Li, Q.C.Feng, L.P.Xin, M.Zhai,
Y.L.Qiu, J.Y.Wei, J.Y.Hu, J.S.Deng, J.Wang,
Y.Urata and W.K.Zheng on behalf of EAFON report:
We have observated the field of GRB080330
(Mao et al. GCN 7537) in R band with TNT
at Xinglong observatory, the magnitude of afterglow
derieved from USNO-b1.0 is R=20.4+/-0.2
with the mean time of 9.4hr after the burst.
This message may be cited
For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org/grb/
GCN Circular 7552
Subject
GRB 080330 Swift-UVOT refined analysis
Date
2008-03-30T23:28:41Z (17 years ago)
From
Paul Kuin at MSSL <npkuin@googlemail.com>
N.P.M. Kuin (MSSL/UCL) and J.Mao (INAF) report on behalf of the
Swift-UVOT team:
The Swift/UVOT started observations of GRB 080330 (Mao et al,
GCN Circ. 7537) with a settling exposure in the UVOT v-filter
starting 2008-03-30 at 03:42:19 U, 63 seconds after the BAT
trigger, and a finding chart exposure in the white filter starting
83 seconds after the trigger. During the subsequent exposure in the
V filter, starting at 189 seconds after the trigger, the spacecraft
lost lock and drifted. In the V image, a clear trail is visible
that all the stars in the field follow. In other filters, there is
no clear evidence of lost counts, except in one image in b. Those
exposures are short, or have much background (white), which suggest
that only a fraction of the counts is lost.
The extraction of the magnitudes below relies on a 5� aperture
around the source. No counts are visible due to the source outside
the aperture in the images. However, these magnitudes should be
regarded as upper limits until a more detailed reduction can be
done. Based on some tests, the magnitude may be underestimated as
much as 0.7 magnitudes. The v-filter data were extracted using
an aperture closely matching the shape of the trail and were
measured from the event data. There is an uncertainty in this
approach as well, since it is not clear what part of the PSF is
sampled. Therefore the V magnitudes can be over-or underestimated
by 0.25 magnitudes.
The observations start before a peak is reached. In the white filter,
a peak is apparent at T+128 +/- 5 seconds. In the v filter data, two
peaks may be present at T+ 438 and 1038 +/- 25s. It is unlikely that
the satellite drift caused these variations because the aperture
included the whole trail. The uvw1 magnitude has upper limits until quite
late in the burst, and must rise between T+791 and T+1416s. This
is an indication of achromatic evolution in this burst.
Only an upper limit is found in the uvw2 and uvm2 filters,
which is consistent with the reported redshift of 1.51 (Malesani,
et al. GCN 7544, and Cucchiara et al. GCN 7547).
Filter Tstart(s) Tstop(s) Exp(s) Mag Mag-error [systematic error]
wh 83 183 98 18.2 0.06 [+0.7]
v 189 588 399.8 18.5-17.2 0.3 [+/-0.25] (*)
uvm2 594 1390 58.4 >18.55 (3 sigma UL)
uvw1 619 638 19.5 >18.02 (3 sigma UL)
u 644 664 19.4 17.14 0.16 [+0.7]
b 669 678 9.6 18.9 0.6 [+0.7]
wh 683 693 9.8 17.76 0.14 [+0.7]
uvw2 698 870 38.9 >18.77 (3 sigma UL)
uvw1 772 791 19.8 >18.04 (3 sigma UL)
u 796 815 19.4 16.66 0.17 [+0.7]
b 822 832 9.6 17.66 0.22 [+0.7]
white 836 979 107.8 17.55 0.03 [+0.7]
v 985 1384 400 18.0-17.2 0.3 [+/-0.25] (*)
uvw1 1416 1436 19.4 17.7 0.3 [+0.7]
b 1464 1483 19.8 18.14 0.22 [+0.7]
white 1490 1499 9.6 17.91 0.15 [+0.7]
(*) For the V magnitudes the range is given as seen in the event data.
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.02 mag in the
direction of the burst (Schlegel et al. 1998).
GCN Circular 7553
Subject
GRB 080330, SMARTS optical/IR afterglow observations
Date
2008-03-31T01:58:36Z (17 years ago)
From
Bethany Cobb at Yale U <cobb@astro.yale.edu>
B. E. Cobb (Yale), part of the larger SMARTS consortium, reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 080330
(GCN 7537, Mao et al.), with a mid-exposure time of
2008-03-30 04:17:29 UT, which is ~36 minutes post-burst.
Several dithered images were obtained in each filter,
with total summed exposure times of 180s in each of BRIYJK and
120s in each of H and V.
The GRB afterglow (GCN 7537, Mao et al.) is detected in all our images
with the following magnitudes (which have not been corrected
for Galactic reddening):
B= 18.27 +/- 0.04
V= 17.90 +/- 0.04
R= 17.59 +/- 0.03
I= 17.09 +/- 0.03
J= 16.36 +/- 0.07
H= 15.76 +/- 0.07
K= 15.14 +/- 0.06
Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against the 2MASS star at
coordinates RA/DEC=11:17:03.34 +30:38:31.1.
The afterglow clearly decays between individual images.
In R-band images taken between 20 and 52 minutes post-burst,
the afterglow decays by 0.7 magnitudes, indicating
an approximate decay rate of alpha = -0.7 (where afterglow flux
is proportional to t^alpha).
GCN Circular 7554
Subject
GRB 080330: REM optical observations
Date
2008-03-31T08:35:23Z (17 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, S. Covino, D. Fugazza, L.A. Antonelli, L. Calzoletti, S.
Campana, G. Chincarini, M.L. Conciatore, S. Cutini, V. D'Elia, F.
D'Alessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel,
E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E.
Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G.
Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on
behalf of the REM team:
The robotic 60-cm REM telescope located at La Silla (Chile) observed
automatically the field of the GRB 080330 (Mao et al., GCN 7537) on
March 30 03:42:11 UT (about 55 seconds after the burst).
We clearly detect the afterglow reported in GCNs 7536 (Klotz et al.),
7537 (Mao et al.) 7538 (Schaefer & Guver), 7539 (Gomboc et al.), 7542
(Bloom & Starr), 7544 (Malesani et al.), 7545 (Clemens et al.), 7546
(Lee et al.), 7550 (Wang et al.).
The R-band light curve between 70s < t-t0 < 1800s clearly shows an
initial rising with a maximum around 330s < t-t0 < 450s and a subsequent
plateau with a possible rebrightening at 900s < t-t0 < 1100s, as noted
in GCNs 7538 (Schaefer & Guver), 7543 (Klotz et al.) and 7552 (Kuin & Mao).
Further analysis is in progress.
GCN Circular 7555
Subject
GRB080330: Swift XRT refined analysis
Date
2008-03-31T12:26:12Z (17 years ago)
From
Jirong Mao at INAF-OAB <jirong.mao@brera.inaf.it>
GRB080330: Swift XRT refined analysis
J. Mao, A. Moretti, and C. Guidorzi (INAF-OAB) report on behalf of the Swift-XRT team:
We have analysed the Swift-XRT data obtained for BAT GRB 080330 (trigger #308041, Mao et al., GCN Circ. 7537). The data consist of 57 s in Windowed Timing (WT) mode, starting 77s after the BAT trigger and 1.36 ks in Photon Counting (PC) mode. The best X-ray position is given in Burrows GCN 7541.
The XRT light-curve can be fit by a power-law with a slope of alpha1=5.22+/-0.30 up to a break at t=167.9+/-7.3 s, which is followed by a shallow decay with a slope of alpha2=0.20+/-0.07.
The spectrum formed from all the WT data can be modeled with a power-law of photon index Gamma=2.03+/-0.09, with the fixed absorbing Galactic column of NH=1.23e20 cm^-2. The spectrum formed from the PC data can be modeled with a power-law of photon index Gamma=1.91 �0.09, with an absorbing column of NH=(2.78+/-1.22)e21 cm^-2 (in excess with respect to the Galactic value of 1.23e20 cm^-2).
If the light-curve continues to decay with a slope of 0.20, after 48 hours, the light curve will have count rate of 0.18 count s^-1, corresponding to an observed (unabsorbed) flux of 5.4e-12(1.3e-11) ergcm^-2 s^-1.
This circular is an official product of the Swift-XRT team.
GCN Circular 7556
Subject
GRB080330: optical observations
Date
2008-04-01T00:18:24Z (17 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Sergeev, M. Andreev (Terskol Branch of Institute of Astronomy), V.
Petkov, A. Kurenya (BNO INR RAS), A. Pozanenko (IKI) on behalf of larger
GRB follow up collaboration report:
We observed the afterglow of GRB 080330 (Mao et al., GCN 7537) with the
Zeiss-2m telescope of Mt.Terskol observatory on March 30. The optical
counterpart (Klotz et al., GCN 7536; Mao et al., GCN 7537, Schaefer & Guver,
GCN 7538; Gomboc et al., GCN 7539; Bloom & Starr, GCN 7542) is clearly
detected.
The photometry of the afterglow against of the SDSS calibration stars (Cool
et al., GCN 7540) of the two epochs of combined images in R is following
T0+ exposure R_mag
Mid time
0.575 d 4x900 s 21.05 +/-0.1
0.654 d 4x900 s 21.28 +/-0.1
Taking into account previous observation (R=20.4+/-0.2 at 9.4 hours after
burst, Wang et al., GCN 7550) and our observations one can suggest the
steepening of a power law decay index up to ~ 1.5 between 9.4 and 15.7 hours
after burst.
GCN Circular 7559
Subject
GRB080330: optical observations
Date
2008-04-01T11:28:09Z (17 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
A. S. Moskvitin, T. A. Fatkhullin, V. N. Komarova, A. N. Burenkov (SAO-RAS,
Nizhnij Arkhyz)
on behalf of larger GRB follow up collaboration report:
We observed the GRB 080330 afterglow (Mao et al., GCN 7537) in the R-band
(exposure 3x600 sec)
with the 1-m telescope of SAO RAS on March 30.928, 18.58 hours after the
trigger.
The weather conditions were tolerable.
The optical transient (Klotz et al., GCN 7536; Mao et al., GCN 7537,
Schaefer & Guver, GCN 7538; Gomboc et al., GCN 7539; Bloom & Starr,
GCN 7542; A. Sergeev et al., GCN 7556) is clearly detected.
The photometry of the afterglow is calibrated against 8 stars from USNO-A2.0.
The R-magnitude of the object is 21.49+/-0.28.
This message may be cited.
GCN Circular 7560
Subject
GRB 080330: Prompt PROMPT Observations
Date
2008-04-02T14:47:56Z (17 years ago)
From
Mark Schubel at UNC/PROMPT <mschubel@physics.unc.edu>
M. Schubel, D. Reichart, M. Nysewander, A. LaCluyze, K. Ivarsen, J. A.
Crain, A. Foster, T. Brennan, J. Haislip, J. Styblova, and A. Trotter
report:
Skynet observed the localization of GRB 080330 (Mao et al., GCN 7537) with
two of the 16" PROMPT telescopes at CTIO beginning 31 seconds after the
trigger (15 seconds after notification) in VRI.
We detect the afterglow (Klotz et al., GCN 7536) in all filters. At 200
seconds after the burst we measure R ~ 17.3 mag (calibrated to 11 USNO B1
stars), at 246 seconds we measure I ~ 16.8 mag (calibrated to 11 USNO B1
stars), and at 292 seconds we measure V ~ 16.6 mag (calibrated to 8 NOMAD
stars).
GCN Circular 7561
Subject
GRB080330: Improved Swift XRT Position
Date
2008-04-03T09:58:40Z (17 years ago)
From
Jirong Mao at INAF-OAB <jirong.mao@brera.inaf.it>
GRB080330: Improved Swift XRT Position
J. Mao (INAF-OAB) report on behalf of the Swift-XRT team:
Since the spacecraft began slowly drifting because the star tracker did
not lock properly on the star field, the XRT position for GRB 080330
that was distributed in GCN Circ. 7537 (Mao et al.) was incorrect. The
initial on-borad XRT position determined immediately after the
spacecraft slew was given by D. N. Burrows (GCN Circ. 7541). The final
accurate XRT position from download data of Malindi is:
RA=169.2584d {11h 17m 02.02s} (J2000)
Dec=30.6229d{+30d 37' 22.58"} (J2000)
with the error radius 3.62 arcsec.
GCN Circular 7568
Subject
GRB 080330: RAPTOR detection of prompt optical flash
Date
2008-04-07T20:55:40Z (17 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis
of Los Alamos National Laboratory report:
Our RAPTOR telescopes responded to Swift trigger 308041
(Mao et al., GCN 7537) at 03:41:39.93 UTC, 23.1 seconds
after the trigger. Our observations show an optical flash
(about 10 s duration) at T ~ 60 s that is simultaneous
with the fourth gamma-ray peak detected by that BAT
(Markwardt et al., GCN 7549). Subsequently, we detect the
rise of an optical afterglow starting at T ~ 150 s that
levels off to a flat plateau at around T ~ 300 s and then
starts to rapidly decay after about T ~ 2000 s. The
unfiltered measurements reported in the following table
are calibrated to the USNO-B1 R band.
t-mid(s) exp(s) mag mag-err
-----------------------------------------
38.78 31.4 (18.3) 5 sigma limit
58.88 5.0 17.46 0.22
83.15 31.3 (18.4) 5 sigma limit
141.96 22.7 17.62 0.10
294.80 22.7 17.03 0.07
504.74 15.0 17.15 0.06
GCN Circular 7580
Subject
GRB 080330 optical observations
Date
2008-04-09T18:36:58Z (17 years ago)
From
AAVSO GRB Network at AAVSO <matthewt@aavso.org>
A. Block (Seeing In The Dark Internet Telescope, and Steward
Observatory, Tucson, AZ) and M. Templeton (AAVSO) report on behalf of
the AAVSO International High Energy Network the following observations
and analysis of the optical afterglow of GRB 080330 (Mao et al., GCN
Circular #7537; Klotz, Boer, and Atteia, GCN #7536):
Adam Block reports unfiltered photometry of the GRB 080330 afterglow
spanning 2008 March 30.1675 UT to 2008 March 30.3273, taken with the
Seeing In The Dark Internet Telescope 14-inch Celestron SCT, using an
SBIG ST1001 camera, located near Mayhill, New Mexico. Forty-seven,
300-second unfiltered exposures were obtained beginning 20 minutes
post-burst, and continuing through t0 + 0.1736 days. Data acquisition
began after the reported peak (D'Avanzo, et al., GCN #7554), but during
the early decay epoch. A break in the light curve is apparent at
approximately 25 minutes after the trigger; only one data point was
obtained prior to this point, and so a slope cannot be reliably derived.
After t0 + 25 minutes, the data are reasonably well fit with a power law
index of -1.104 +/- 0.001, with a zero point unfiltered magnitude of
22.65 (m = m(t+1day)). However, the light curve appeared to briefly
rebrighten by more than 0.2 magnitudes (1-sigma error = 0.09 mag)
approximately 70 minutes post-burst, suggesting a late-time
manifestation of the rebrightening seen during early light (Schaefer and
Guver, GCN #7538). These observations are consistent with other
optical observations taken during this time frame; observations through
t0 + 250 minutes do not show evidence for the steeper slope described by
Sergeev et al (GCN #7556) for data taken at t > t0 + 0.5 days,
suggesting this break occurred between the end of these observations and
the start of observations by Sergeev et al.
A report detailing these observations is available at the following URL:
ftp://ftp.aavso.org/grb/AdamBlock_GRB080330_2454558.33910_.txt
The initial image of the GRB field is available at the following URL:
ftp://ftp.aavso.org/grb/AdamBlock_GRB080330_2454558.33910_.fits
A light curve of the unfiltered photometry is available at the following
URL:
http://www.caelumobservatory.com/outgoing/grb080330LOG.jpg
Photometry and a full description of the observations will appear in the
Journal of the AAVSO, and are available from A. Block upon request to
ngc1535@caelumobservatory.com.
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
GCN Circular 7583
Subject
GRB 080330: Swift-XRT refined position retraction
Date
2008-04-11T14:32:16Z (17 years ago)
From
Jirong Mao at INAF-OAB <jirong.mao@brera.inaf.it>
J. Mao and C. Guidorzi (INAF-OAB) on behalf of the Swift-XRT team report:
A re-examination of the XRT data on GRB080330 (Mao et al.
GCN Circ. 7537) taken during the first orbit revealed that
the XRT improved position distributed by Mao (GCN Circ. 7561)
is incorrect due to star tracker loss-of-lock problems already
mentioned by Burrows (GCN Circ. 7541).
We re-processed the first orbit PC data and extracted the following
refined position from 136 to 311 s after the burst,
when the star tracker drifting seems to have little impact:
RA, Dec = 169.26950, +30.62355 which is equivalent to:
RA (J2000): 11h 17m 04.68s
Dec (J2000): +30d 37' 24.78"
with an uncertainty of 4.0 arcsec (radius, 90% confidence).
This is consistent with the optical ground-based position
(2.7 arcsec away from the PAIRITEL position reported by
Bloom and Starr, GCN Circ. 7542).
This is an official product of the Swift XRT team.
GCN Circular 7585
Subject
GRB080330: MAGIC telescope GeV observation
Date
2008-04-11T23:41:23Z (17 years ago)
From
Markus Garczarczyk at MPI/MAGIC <garcz@mppmu.mpg.de>
Gaug M., Garczarczyk M., Antonelli A., Bastieri D., Covino S., Galante N.,
La Barbera A., Longo F. and Scapin V. for the MAGIC collaboration
The MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up
observation of the BAT burst GRB080330 (GCN circular 7537, Mao et al.).
We received the GCN alert at 03:41:33 UT (T0+16s), data taking with MAGIC
started at 03:42:47 UT (T0+91s), short after the prompt emission phase
measured to be T90=61+/-9s. The observation was carried out at a zenith
angle of 48 degrees. The observation continued for 1039s.
No evidence for VHE gamma-ray emission above the analysis threshold of
313 GeV was found. The observation was carried out in (less sensitive)
moon-observation mode.
A preliminary analysis, for the hypothesis of steady emission and
assumption of a differential photon spectral index of -2.5, yields the
following 95% CL differential flux upper limits, including a 30%
systematic uncertainty on the telescope efficiency:
E (175- 300 GeV): 0.36 * 10^-10 erg/cm^-2/s
E (300-1000 GeV): 0.49 * 10^-10 erg/cm^-2/s
for a time window from 03:42:47 UT to 03:59:01 UT
We can also exclude emission of a constant flux in any 100s time bin
smaller than:
E (175- 300 GeV): 8.42 * 10^-10 erg/cm^-2/s
E (300-1000 GeV): 2.05 * 10^-10 erg/cm^-2/s
for a time window from 03:42:47 UT to 03:59:01 UT
This message can be cited.