GRB 080212
GCN Circular 7321
Subject
GRB 080212: Mount Abu NIR observations
Date
2008-02-19T06:29:45Z (18 years ago)
From
Lokesh Kumar Dewangan at Phys Res Lab, Ahmedabad,India <lokeshd@prl.res.in>
Lokesh, V. Venkat, J. Jain, S. Vadawale and B.G. Anandarao
Physical Research Laboratory, Ahmedabad, India.
We made infrared photometry in J band at Mt. Abu 1.2 m Cassegrain telescope
using NICMOS camera on the GRB 080212 (Ziaeepour et al. GCN 7296)
during 2008 Feb 13 under good sky conditions. The H band magnitude was
earlier reported by P. D'Avanzo et. al (GCN 7310).
The calibration was made on the bright star SAO 183333.
The overall integration time and the magnitude along with the associated
error are given below:
UT Integration time J band magnitude+/-error
13.97 1080s 16.8+/-0.1
GCN Circular 7311
Subject
GRB 080212: VLT optical rapid decay
Date
2008-02-14T19:37:21Z (18 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, D. Fugazza (INAF-OAB), L.A. Antonelli (INAF-OAR), S.
Covino, G. Chincarini, C. Guidorzi, G. Tagliaferri (INAF-OAB), V.
D'Elia, F. Fiore, S. Piranomonte, L. Stella (INAF-OAR), M. Della Valle
(INAF-OAA), S. D. Vergani (DIAS-DCU) report on behalf of the MISTICI
collaboration:
We observed the optical afterglow of GRB 080212 (Ziaeepour et al., GCN
7296) with the ESO-VLT equipped with the FORS2 camera in imaging mode at
three different epochs. Observations have been carried out in R-band on
Feb 13.3101 UT, Feb 13.3682 UT and Feb 14.2838 UT (0.58, 0.64 and 1.55
days after the burst, respectively).
We found that between the first two epochs the afterglow faded very
rapidly, with a decay index of alpha ~ 5.5. Very likely, the afterglow
underwent a remarkable increase of its optical/NIR flux, probably
related to the brightening observed in the X-rays about 4 hours before
our VLT observations (see D'Avanzo et al., GCN 7310).
Assuming the above decay index, we estimate R ~ 20.8 at the epoch of the
REM detection (D'Avanzo et al., GCN 7302) with an implied colour R-H~5
The decay of the afterglow then slowed down between the last two epochs
and we measure R~25 in our last observation.
GCN Circular 7310
Subject
GRB 080212: REM refined analysis
Date
2008-02-13T18:12:44Z (18 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, L.A. Antonelli, S. Covino, D. Fugazza, 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, D. Malesani, N. Masetti, A. Melandri, E.J.A. 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:
We performed a more careful analysis of the REM H-band images of GRB
080212 (Ziaeepour et al. GCN 7296). We confirm the afterglow detection
reported in D'Avanzo et al. (GCN 7302).The observations have been
carried out on Feb 13.2063 UT (about 11.4 hours after the burst) and
consist of three sets of images (lasting 10, 30 and 60 s respectively).
We confirm the presence of a H = 15.3 � 0.2 object (calibrated against
the 2MASS catalogue) about 2.5" East of the K-type star (Berger, GCNs
7294 & 7304). The object is visible in both the 30 s and 60 s images at
the following coordinates (J2000):
R.A. = 15:24:35.42
Dec. = -22:44:28.8
with an uncertainty of 0.3" (the REM pixel size is 1.2"/pixel) .
When compared to the GROND optical detection (obtained about 1.7 hours
later, Kuepcue Yoldas et al. GCN 7303), our H-band measurement implies
a colour I-H ~ 7 mag, which is very red. A possible way out is to invoke
remarkable flaring activity around the time of the REM observation. We
note that the X-ray light curve (available at:
http://www.swift.ac.uk/xrt_curves/00303105/) shows some evidence for
rebrightening about 2 hr before the REM observation.
A finding chart, showing the detection at different H-band images can be
found at the following URL:
http://www.brera.inaf.it/utenti/davanzo/public/grb/GRB080212/GRB080212_REMIR_FC.jpg
GCN Circular 7308
Subject
VLA radio upper limit on GRB 080212
Date
2008-02-13T14:10:29Z (18 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward
GRB 080212 (GCN 7296) at a frequency of 8.46 GHz on 2008 February
13.53 UT. The radio afterglow of the GRB is undetected at the
Swift-XRT position (GCN 7300) or optical afterglow position (GCN 7303).
The peak flux density at the afterglow position is 83 +/- 51 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 7307
Subject
Swift/UVOT refined analysis of GRB080212
Date
2008-02-13T13:55:09Z (18 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale and H. Ziaeepour (MSSL/UCL)
report on behalf of the Swift team:
The Swift/UVOT observed the field of GRB 080212 (trigger 303105)
starting 110 seconds after the BAT trigger (Ziaeepour et al
GCN Circ. 7296), which occurred at 17:34:33 UT.
A source is detected in the enhanced XRT error circle reported
by Evans et al (GCN circ. 7300), blended with the K-type star
mentioned in GCN 7304 by Berger et al.
The detection is only in the early V band exposures. There was
no other 3-sigma detection of the afterglow in any exposure
in any of the UVOT filters.
We do caution that photometry for this burst has been
carried out in very difficult conditions. Furthermore, no
correction has been made for the non-negligible Galactic
extinction towards the burtst, which amounts to E(B-V) = 0.16
The detections and 3-sigma upper limits in the UVOT photometric
system (Poole et al MNRAS 383, 627 (2008)) are summarized in
the following table:
Filter Tstart(s) Tstop(s) Exp(s) Mag / Upper limit
V 110 510 393 17.8 +/- 0.1
V 4734 6166 393 19.3 +/- 0.3
V 21968 22876 893 >20.3
B 4323 4522 393 >20.7
B 11320 40999 1774 >21.2
U 4119 5548 393 >20.3
U 10408 40703 3400 >21.5
UW1 3919 5344 393 >20.0
UW1 9502 50920 4309 >21.2
UM2 3741 6300 323 >19.3
UM2 15290 45066 3413 >20.6
UW2 4529 5961 393 >19.4
UW2 21062 21961 893 >20.7
GCN Circular 7306
Subject
GRB 080212, Swift-BAT refined analysis
Date
2008-02-13T13:41:24Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
K. McLean (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (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), H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080212 (trigger #303105)
(Ziaeepour, et al., GCN Circ. 7296). The BAT ground-calculated position is
RA, Dec = 231.145, -22.739 deg, which is
RA(J2000) = 15h 24m 34.8s
Dec(J2000) = -22d 44' 19"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
The mask-weighted light curve shows the main burst acivity starting
at about T-60 sec, the main peak at ~T+5 sec, and ending at about T+110 sec.
There is a weak peak at T+250 to T+350 sec, which matches a flare
in in the XRT lighcurve peaking at about T+250 sec.
T90 (15-350 keV) is 123 +- 13 sec (estimated error including systematics).
The time-averaged spectrum from T-60.5 to T+75.7 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.31 +- 0.64,
and Epeak of 67.6 +- 13.1 keV (chi squared 52.75 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 2.9 +- 0.3 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+3.75 sec in the 15-150 keV band is
1.2 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.59 +- 0.12 (chi squared 68.06 for 57 d.o.f.). 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/303105/BA/
GCN Circular 7305
Subject
GRB080212: Optical afterglow candidate observed by MITSuME Telescope
Date
2008-02-13T11:50:53Z (18 years ago)
From
Michitoshi Yoshida at Okayama Astrophysical Obs <yoshida@oao.nao.ac.jp>
M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ)
and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:
We performed optical imaging observation (g', Rc, and Ic) of the
field of GRB 080212 (Ziaeepour et al. GCN 7296) with 50cm MITSuME
telescope at Okayama Astrophysical Observatory from UT 17:36:37
(124 sec after the trigger) to UT 20:30:38 on Feb 12 2008.
We found a 18 mag star in the vicinity of the XRT position (Goad
et al. GCN 7300). This is the late-K star reported by Berger (GCN
7304). Although we could not spatially resolve the faint source
close to this star reported by Berger (GCN7304), we found that
a fading component is overlaid on the star. This component is
a GRB afterglow candidate. We estimated the magnitudes of the
fading component by subtracting the flux of the star at 2 hours
after the trigger from the star magnitude at early time.
The estimated magnitudes of the fading component are summarized
below.
Observation date 2008-02-12 UT
mid-UT exp-T g' Rc Ic
---------------------------------------------------------
17:42:47 10min 19.46+-0.26 17.77+-0.15 17.98+-0.22
18:00:27 22min > 21.0 18.77+-0.14 18.91+-0.21
18:19:08 52min > 21.0 19.88+-0.10 > 20.5
18:58:37 113min > 21.0 > 20.5 > 20.5
---------------------------------------------------------
GCN Circular 7304
Subject
GRB 080212: Gemini-South optical observations
Date
2008-02-13T08:13:50Z (18 years ago)
From
Edo Berger at Princton U <eberger@astro.princeton.edu>
E. Berger (Princeton) reports:
"A 900-sec spectrum obtained with Gemini-South/GMOS reveals that the
object near the XRT position is a late-K star and not a galaxy as
initially indicated in GCN 7294.
In a 60 sec r-band acquisition image we find a faint source coincident
with the XRT position at:
RA = 15:24:35.4
DEC = -22:44:30 (J2000)
This object is consistent with the positions reoprted in GCNs 7302 and
7303."
GCN Circular 7303
Subject
GRB 080212: GROND detects afterglow
Date
2008-02-13T08:08:18Z (18 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
A. Kuepcue Yoldas, A. Yoldas, J. Greiner, T. Kruehler (all MPE Garching),
A. Rossi (Tautenburg Obs) report for the GROND team:
We observed the field of GRB 080212 (trigger 303105) detected by Swift/BAT
(Ziaeepour et al. 2008, GCN 7296) simultaneously in grizJHK with GROND
(Greiner et al. 2008, astro-ph/0801.4801), mounted at the 2.2m MPI/ESO
telescope at La Silla (Chile). Observations started on Feb. 13, at 05:30 UT
(12 hrs after the GRB), when the GRB location was becoming visible at
20 degrees above horizon.
We detect a new source in all filters, suggesting the Ly-break being below the
g'-band (and thus z<3.5). It is clearly separated from the galaxy mentioned by
Berger et al. (2008, GCN 7294