GRB 060206
GCN Circular 4901
Subject
GRB060206: optical observation
Date
2006-03-22T01:49:52Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
D. Sharapov (MAO, and NOT, La Palma), M. Ibrahimov, (MAO), A. Pozanenko
(IKI) on behalf of larger GRB follow up collaboration report:
We observed the localization of GRB 060206 (Morris et al., GCN 4682) with
1.5m telescope of Maidanak Astronomical Observatory in R-band between (UT)
Feb. 07 23:26:38 and Feb. 08 00:36:06 (18x180 s) with a mean seeing 0.95".
We detect the afterglow (Fynbo et al., GCN 4683) at R=20.78 +/- 0.03 at
mean time (UT) Feb. 8.000. Calibration is based on SDSS stars; Cool et al.,
GCN 4695 using the transformation equations (Lupton, 2005). Combining this
value with a light curve presented by Stanek et al. (astro-ph/0602495) one
can suggest the jet brake later than 0.6 days. The value R=20.78 +/- 0.03 is
also correlated with possible XRT light curve rebrightening (XRT light
curve presented in the astro-ph/0602495). There is a tentative short time
scale rebrightening within our observation; more detailed calibration is
underway.
The stacked image can be found in
http://grb.rssi.ru/GRB060206/GRB060206_060207_AZT22_R.jpg
The message may be cited.
GCN Circular 4768
Subject
GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
Date
2006-02-17T05:31:02Z (20 years ago)
From
Daniel E. Reichart at U.North Carolina <reichart@physics.unc.edu>
D. Reichart, A. LaCluyze, M. Nysewander, and J. Haislip report on behalf of
the UNC team of the FUN GRB collaboration:
In addition to detecting the afterglow (Fynbo et al., GCN 4683) of GRB
060206 (Morris et al., GCN 4682) in I band 27.0 hours after the burst with
PROMPT (Kirschbrown et al., GCN 4712; LaCluyze et al., GCN 4750) and 51.3
hours after the burst with SOAR (LaCluyze et al., GCN 4750), we detected
the afterglow in i' band 26.0 hours after the burst with PROMPT, in V band
51.7 hours after the burst with SOAR, and in R band 51.9 hours after the
burst with SOAR.
At 26.0 hours after the burst, we measure i' = 19.83 +/- 0.22 mag.
From our V and R photometry and a simple model of the Ly-alpha forest, we
infer i' = 21.55 +/- 0.08 mag at 51.8 hours after the burst. (As a check,
simple interpolation between our R and I photometry yeilds i' = 21.36 +/-
0.05 mag at 51.6 hours after the burst.) This implies a temporal index of
-2.3 +/- 0.3 between 26.0 and 51.8 hours after the burst, which is
consistent with and independent of our measurement of -2.20 +/- 0.26
between 27.0 and 51.3 hours after the burst in I band (LaCluyze et al., GCN
4750).
PROMPT and SOAR light curves can be viewed at:
http://www.physics.unc.edu/~reichart/grb060206.eps
Continued monitoring is strongly encouraged, particularly given that no
break is observed in X rays (Morris et al., GCN 4764).
GCN Circular 4764
Subject
GRB060206: Swift XRT observations of an unbroken powerlaw decay
Date
2006-02-15T23:34:08Z (20 years ago)
From
David Morris at PSU/Swift-XRT <morris@astro.psu.edu>
D. C. Morris (PSU), C. Pagani (PSU), D. N. Burrows (PSU), J. A. Kennea
(PSU) and K.Page (U. Leicester) report on behalf of the Swift XRT team:
The Swift XRT has continued to monitor the light curve of GRB060206 with
data taken as late as T+8 days. Our complete X-ray dataset from T+5ks to
T+700ks remains consistent with a single unbroken powerlaw decay with
alpha=1.35+/-0.15. We note that there is apparent variability, both
positive and negative, on the timescale of days in the X-ray lightcurve
somewhat larger than is implied by simple counting statistics. Our data
are not consistent, however, with a break to a slope of -2.2 at T+27
hours and thus we cannot confirm the presence of the jet break reported
in I-band observations by LaCluyze et al. (GCN 4750).
The XRT data remain consistent with the prediction by Palmer et al (GCN
4597) of a jet break at 8.6 or 10.4 days (743ks or 899ks). The XRT
countrate during the last observation, on February 14th, was 2e-3 cts/s,
equivalent to a flux of approximately 1.5e-13 ergs/cm2/s. Observations
are ongoing.
The XRT lightcurve can be viewed at
http://www.swift.psu.edu/images/GRB060206.jpg
This circular is an official product of the Swift XRT Team.
GCN Circular 4750
Subject
GRB 060206: SOAR Detections
Date
2006-02-12T03:18:22Z (20 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@physics.unc.edu>
A. LaCluyze, M. Nysewander, J. Haislip, A. de Oliveira, D. Reichart, J.
Santos, A. Alvarez, S. Heathcote, J. C. Clemens, and A. Trotter report on
behalf of the UNC team of the FUN GRB collaboration:
We observed the localization of GRB 060206 (Morris et al., GCN 4682) with
4.1m SOAR at CTIO in VRI beginning 50.8 hours after the burst.
We detect the afterglow (Fynbo et al., GCN 4683) at I = 20.70 +/- 0.04 mag
at an effective time of 51.3 hours after the burst (calibrated to six SDSS
stars; Cool et al., GCN 4695; using the transformation equations of Smith
et al. 2002.)
A more careful analysis of PROMPT's I-band detection from the night before
(Kirschbrown et al., GCN 4712) yeilds I = 19.17 +/- 0.18 mag at an
effective time of 27.0 hours after the burst. This implies a temporal
index of -2.20 +/- 0.26 between 27.0 and 51.3 hours after the burst, which
is significantly steeper than the temporal index that we measured with
PROMPT on the first night (-1.0; Haislip et al., GCN 4709)
This suggests that the jet is breaking, and at a significantly earlier time
than estimated by Palmer et al. (GCN 4697).
Continued monitoring is encouraged.
GCN Circular 4732
Subject
GRB060206, optical observations
Date
2006-02-10T13:12:12Z (20 years ago)
From
Adalberto Piccioni at Astronomy, Bologna U. <piccioni@ermione.bo.astro.it>
G. Greco (Bologna University), F. Terra, D. Nanni, (Second University
of Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni
(Bologna University), G. Pizzichini (INAF/IASF Bo) and R. Gualandi
(INAF Bologna) report:
During the night of February 6 -7, 2006 we observed the OT of
GRB 060206 (Morris et al. GCN 4682; Fynbo et al. GCN 4683) with
the 152 cm Loiano telescope equipped with the BFOSC camera system.
The weather conditions were not photometric and the seeing was
2.5 arcsec.
We obtained 3 images x 20 minutes in Rc filter, 2 x 30 minutes in V
and 2 x 20 minutes in I. The 2 V frames have been co-added.
We determined the following magnitudes derived from USNO-B1.0 (R1)
catalogue for the Rc and I bands and NOMAD catalogue for V band:
mean time (UT).......filter................ mag
6.960 ................ Rc ............ 19.78+/-0.15
6.976 ................ Rc ............ 19.70+/-0.11
6.990 ................ Rc ............ 19.79+/-0.12
7.025 ................ V ............. 20.06+/-0.17
7.054 ................ I ............. 19.16+/-0.11
7.069 ................ I ............. 19.19+/-0.10
We thank very much N. Masetti, who has obtained the images.
Our RVI images, in which the comparison stars are marked, have been
posted in our public directory from where they can be retrieved by
sftp using
hostname: ermione.bo.astro.it
username: publicGRB
password: GRB_bo.
GCN Circular 4722
Subject
GRB 060206: Swift/UVOT Observations
Date
2006-02-09T22:27:58Z (20 years ago)
From
Padi Boyd at GSFC <padi@milkyway.gsfc.nasa.gov>
P. Boyd (GSFC), D. Morris (PSU), F. Marshall (GSFC), N. Gehrels (GSFC)
on behalf of the Swift/UVOT team report:
The Swift/UVOT began observing the bright afterglow of GRB 060206 at
04:47:52 UT on 2006-02-06, approximately 57s after the BAT trigger (Morris
et al., GCN 4682). The afterglow is well detected in the individual B and
V exposures during the initial observation. The afterglow re-brightens in
both filters between 2000 to 5000-s after the BAT trigger. After this
event, the flux decays in both filters with a slope of ~1.15.
Filter T_range(s) Exp(s) Average mag
V 57-36588 2618 18.8
B 1662-34946 2911 21.3
Reported times are in seconds since BAT trigger.
In a follow-up observation, beginning about 0.8 d after the BAT trigger,
the source is not detected in B nor V down to the following 3-sigma
magnitude upper limits:
Filter T_range(s) Exp(s) mag upper limit
V 69308-150688 5001 >21.7
B 69656-150353 4679 >22.6
The afterglow is not detected in any other UVOT filter down to the
following 3-sigma magnitude upper limits:
Filter T_range(s) Exp(s) mag
U 1637-23385 1161 >21.5
UVW1 1757-5619 256 >20.6
UVM2 1733-30466 514 >21.3
UVW2 1686-35861 2638 >22.7
These magnitudes are uncorrected for Galactic extinction;
E(B-V) = 0.013.
GCN Circular 4716
Subject
GRB 060206: near-infrared observations (JK' imaging)
Date
2006-02-09T07:08:47Z (20 years ago)
From
Hiroshi TERADA at Subaru Telescope,NAOJ <terada@naoj.org>
H. Terada, T.-S. Pyo (Subaru Telescope, NAOJ), N. Kobayashi
(University of Tokyo) and N. Kawai (Tokyo Tech) report:
"Near-infrared photometry of the afterglow of GRB 060206
(Morris et al., GCN #4682) in the J, K'-bands was performed with IRCS
(Infrared Camera and Spectrograph) on the SUBARU Telescope at February
7.5 UT. An average seeing was 0.5 arcsec in the J-band and 0.3 arcsec
in the K'-band.
The magnitude of the afterglow was J=18.77 +/ -0.04 at 10:38-11:04 UT
(t=30.1 hr) and K'=17.78 +/ -0.01 at 13:37-14:30 UT (t=33.3 hr). The
near-infrared decay index of the afterglow is estimated to be -1.11 in
the J-band and -1.22 in the K'-band from comparison with the earlier
report (J=15.96 and Ks=14.54 at t=2.9 hr, GCN #4702)."
This message may be cited.
GCN Circular 4715
Subject
GRB 060206: WSRT Radio Observations
Date
2006-02-08T15:25:51Z (20 years ago)
From
Alexander van der Horst at U of Amsterdam <avdhorst@science.uva.nl>
A.J. van der Horst (University of Amsterdam) reports on behalf of a larger
collaboration:
"We observed the position of the GRB 060206 afterglow at 4.9 GHz with the
Westerbork Synthesis Radio Telescope at February 7 21.89 UT to February 8
9.86 UT, i.e. 1.71 - 2.21 days after the burst (GCN 4682).
We do not detect a radio source within the SWIFT/XRT error circle (GCN
4689), in particular at the position of the optical counterpart (GCN 4683,
GCN 4684