- GCN/BACODINE POSITION NOTICE
TITLE: GCN/INTEGRAL NOTICE
NOTICE_DATE: Sat 18 Dec 04 15:47:15 UT
NOTICE_TYPE: INTEGRAL Wakeup
TRIGGER_NUM: 2072, Sub_Num: 0
GRB_RA: 24.8468d {+01h 39m 23s} (J2000),
24.9449d {+01h 39m 47s} (current),
23.8685d {+01h 35m 28s} (1950)
GRB_DEC: +71.3528d {+71d 21' 10"} (J2000),
+71.3779d {+71d 22' 40"} (current),
+71.0992d {+71d 05' 57"} (1950)
GRB_ERROR: 2.77 [arcmin, radius, statistical only]
GRB_INTEN: 14.28 [sigma]
GRB_TIME: 56762.47 SOD {15:46:02.47} UT
GRB_DATE: 13357 TJD; 353 DOY; 04/12/18
SC_RA: 2.61 [deg] (J2000)
SC_DEC: 61.04 [deg] (J2000)
SUN_POSTN: 266.81d {+17h 47m 15s} -23.41d {-23d 24' 20"}
SUN_DIST: 120.97 [deg]
MOON_POSTN: 358.07d {+23h 52m 16s} -4.07d {-04d 04' 10"}
MOON_DIST: 77.48 [deg]
GAL_COORDS: 126.79, 8.84 [deg] galactic lon,lat of the burst
ECL_COORDS: 59.88, 54.67 [deg] ecliptic lon,lat of the burst
COMMENTS: INTEGRAL GRB Coordinates.
COMMENTS: Possibly real GRB event
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/INTEGRAL NOTICE
NOTICE_DATE: Sat 18 Dec 04 15:50:19 UT
NOTICE_TYPE: INTEGRAL Refined
TRIGGER_NUM: 2072, Sub_Num: 1
GRB_RA: 24.8372d {+01h 39m 21s} (J2000),
24.9353d {+01h 39m 44s} (current),
23.8590d {+01h 35m 26s} (1950)
GRB_DEC: +71.3568d {+71d 21' 25"} (J2000),
+71.3819d {+71d 22' 55"} (current),
+71.1032d {+71d 06' 11"} (1950)
GRB_ERROR: 2.75 [arcmin, radius, statistical only]
GRB_INTEN: 14.70 [sigma]
GRB_TIME: 56778.81 SOD {15:46:18.81} UT
GRB_DATE: 13357 TJD; 353 DOY; 04/12/18
SC_RA: 2.61 [deg] (J2000)
SC_DEC: 61.04 [deg] (J2000)
SUN_POSTN: 266.81d {+17h 47m 15s} -23.41d {-23d 24' 20"}
SUN_DIST: 120.97 [deg]
MOON_POSTN: 358.07d {+23h 52m 17s} -4.07d {-04d 04' 06"}
MOON_DIST: 77.48 [deg]
GAL_COORDS: 126.78, 8.84 [deg] galactic lon,lat of the burst
ECL_COORDS: 59.88, 54.68 [deg] ecliptic lon,lat of the burst
COMMENTS: INTEGRAL GRB Coordinates.
COMMENTS: Possibly real GRB event
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/INTEGRAL NOTICE
NOTICE_DATE: Sat 18 Dec 04 17:11:29 UT
NOTICE_TYPE: INTEGRAL Offline
TRIGGER_NUM: 2072, Sub_Num: 1
GRB_RA: 24.7729d {+01h 39m 06s} (J2000),
24.8709d {+01h 39m 29s} (current),
23.7960d {+01h 35m 11s} (1950)
GRB_DEC: +71.3344d {+71d 20' 04"} (J2000),
+71.3595d {+71d 21' 34"} (current),
+71.0806d {+71d 04' 50"} (1950)
GRB_ERROR: 2.50 [arcmin, radius, statistical only]
GRB_INTEN: 14.28 [sigma]
GRB_TIME: 56762.47 SOD {15:46:02.47} UT
GRB_DATE: 13357 TJD; 353 DOY; 04/12/18
SC_RA: 2.61 [deg] (J2000)
SC_DEC: 61.04 [deg] (J2000)
SUN_POSTN: 266.81d {+17h 47m 15s} -23.41d {-23d 24' 20"}
SUN_DIST: 120.96 [deg]
MOON_POSTN: 358.07d {+23h 52m 16s} -4.07d {-04d 04' 10"}
MOON_DIST: 77.45 [deg]
GAL_COORDS: 126.77, 8.82 [deg] galactic lon,lat of the burst
ECL_COORDS: 59.83, 54.67 [deg] ecliptic lon,lat of the burst
COMMENTS: INTEGRAL GRB Coordinates.
COMMENTS: REFINED_COORDINATES_AFTER_OFFLINE_ANALYSIS
- GCN notice #2858
S.Mereghetti, D. Gotz, (IASF, Milano), S.Shaw, M. Beck, A. Paizis
(ISDC, Versoix), J.Borkowski (CAMK, Torun) on behalf of the IBAS
Localization Team report:
A 60 s long GRB has been detected with the INTEGRAL Burst Alert System
(IBAS) on December 18 at 15:45:25 UT. The GRB has been detected with
IBIS/ISGRI in the 15-200 keV band (IBAS Alert # 2072).
Its coordinates (J2000) are:
R.A.: 24.7731 [degrees],
DEC.: 71.3346 [degrees]
with an uncertainty of 2.5 arcmin (90% c.l. radius)
The preliminary peak flux in the 20-200 keV range is about 3
photons/cmsq/s (1.6E-7 erg/cmsq/s) (1 s integration time).
This message can be cited.
- GCN notice #2860
K. Torii (Osaka University) reports:
The entire error region of GRB 041218 (Mereghetti, et al., GCN 2858)
was observed with the 14-inch Automated Response Telescope at Osaka
University in Toyonaka. The observation started at 2004 December 18
15:47:34 UT while the early data suffered from cloud passages.
In a stacked image (60-s x 4 frames obtained between 15:58 UT and
16:09 UT), we do not identify a new object brighter than about 16.0
mag (USNO-A2.0 R). On the other hand, we note a low S/N
afterglow candidate (R~16.5) at position
(R.A., Dec.) = (01 39 7.6, +71 20 30) (J2000) (1.5" uncertainty)
in the preliminary analysis.
- GCN notice #2861
J. Gorosabel, A. de Ugarte, A.J. Castro-Tirado, M.Jelinek (IAA-CSIC),
S. Pedraz (CAHA), report
"We have acquired multicolour optical observations with
the 2.2m CAHA telescope (+BUSCA) starting at ~18:00 UT at the
position of GRB 041218 (GCN 2858). Visual comparison
reveals an object that shows a clear decay. The position
is:
RA(J2000)=01:39:07.7
DEC(J2009)=+71:20:28.8
Further observations are in progress.
This message can be cited.
- GCN notice #2863
G. Greco, C. Bartolini, A. Guarnieri, and A. Piccioni (Universita' di
Bologna),
P. Ferrero (IASF/CNR/ Bologna/ Osservatorio e Universita' di Teramo),
G. Pizzichini (IASF/CNR/ Bologna) and R.Gualandi (INAF/ Bologna
Observatory)
report:
We observed the error region of GRB 041218 (Mereghetti,et al.,GCN 2858)
with the 152 cm telescope in Loiano (Bologna University) in clear sky
conditions (seeing ~2.5).
The first observation started at 18h05m58s UT; the acquisition sequence
was: R band 15x600 sec exposures; B band 1x1200 sec; V band 1X600 sec;
R band 1x600 sec.
We detect the candidate reported by Torii (GCN 2860) and Gorosabel et
al. (GCN 2861).
Our very preliminary estimate of the magnitude of the afterglow
candidate in the first frame is R ~ 19.5.
More precise analysis is in progress.
- GCN notice #2869
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have acquired BVRcIc all-sky photometry for
a 11x11 arcmin field centered on the afterglow coordinates for the
INTEGRAL burst GRB041218 (Mereghetti et al., GCN 2858;
Torii GCN 2860, Gorosabel et al. GCN 2861)
with the USNOFS 1.0-m telescope on one marginally photometric
night. Stars brighter than V=13.0 are saturated and
should be used with care. We have placed the photometric data
on our anonymous ftp site:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb041218.dat
The astrometry in this file is based on linear plate solutions
with respect to USNOA2. The external errors are less than 300mas.
The estimated external photometric error is about 0.04mag
due to the poor seeing, and will be improved with additional
calibration nights after Christmas.
As always, you should check the dates on the .dat file prior to
final publication to get the latest photometry. There is
a README file on the ftp directory to give you information
about the procedures used to calibrate these fields.
- GCN notice #2873
J. P. Halpern and S. Tuttle (Columbia U.) report for the erstwhile
MDM Observatory GRB follow-up team:
"We observed INTEGRAL GRB 041218 (Mereghetti et al. GCN #2858) in the
R-band using the MDM 1.3m telescope under conditions of poor seeing.
A total of 50 minutes of exposure centered at Dec. 19, 05:03 UT, or
13.3 hours after the burst showed a faint object of R = 22.15 +/- 0.25
at the position of the OT reported by Torii et al (GCN #2860),
Gorosabel et al. (GCN #2861), and Greco et al. (GCN #2863).
We use for comparison the USNO B1.0 star 1613-0027268 located at
R.A. = 01h39m04s.17, Decl. = +71o21'06".0 (J2000) for which
Henden (GCN #2869) gives Rc = 16.65.
We note that there is considerable Galactic extinction in this direction,
E(B-V)=0.63 corresponding to A_R=1.67 (Schlegel et al. 1998)."
An image is posted at:
http://www.astro.columbia.edu/~jules/grb/041218/
This message can be cited.
- GCN notice #2875
S. Bradley Cenko reports on behalf of the Caltech-NRAO-Carnegie GRB
Collaboration:
"We have continued to image the afterglow candidate of the Integral
GRB041218 (GCNs 2858, 2860, 2861) with the robotic Palomar 60-inch
telescope. We have obtained 9 x 180-second images in Johnson B and V,
Kron R and I, and Gunn z filters. Extremely poor weather conditions (2 -
4 arcsecond seeing) have greatly limited our sensitivity.
We were unable to detect the afterglow in any of our observed bands. The
mean observing time and limiting magnitudes of our observations are
outlined below:
Filter UT (Dec. 19) Limiting Magnitude
----------------------------------------------------------------------
B 04:47 20.5
V 05:01 20.3
R 05:17 20.1
I 05:38 19.7
z 05:53 19.4
No further observations at the Palomar 60-inch are planned."
- GCN notice #2877
O. Trondal (otrondal@online.no) Oslo, Norway reports:
"I observed the error region of GRB041218 for the INTEGRAL burst GRB041218
(Mereghetti et al., GCN 2858) with my 25cm Schmidt-Cassegrain telescope and
unfiltered CCD (MX916) under clear sky conditions.
I took 8 unfilterd 60 s images. The afterglow reported by Torii (GCN 2860)
and Gorosabel et. al. (GCN 2861) is visible in the co-added image at RA
01:39:07.57 Dec +71:20:28.5 (2000.0, USNOA2.0 reference, average residual
0.4 arc secs), at magnitude V=18.6 +/- 0.2 using the field calibration by
Henden (GCN 2896).
The observation started 16:07:04 UT and ended 16:15:51 UT on December 18,
2004.
Here is image and animation with DSS1 :
http://www.geocities.com/Odd_Trondal/grb041218.htm"
- GCN notice #2878
A. Monfardini (Liverpool), C. Mottram (Liverpool), C. Guidorzi
(Liverpool), E. Rol (Leicester), C. Mundell (Liverpool),
I. Steele (Liverpool), R. Smith (Liverpool), A. Gomboc (Ljubljana) report:
"We observed the afterglow of GRB041218 with the 2.0m Liverpool Telescope
on La Palma. We obtained RI imaging commencing 4.3 hours after the
burst under poor seeing conditions. We report R and I estimates:
I = 20.1 +/- 0.2 mag at Dec 18.840 (exposure time = 2x120s)
R = 20.6 +/- 0.2 mag at Dec 18.837 (exposure time = 2x120s)
These values were derived using Henden calibration (GCN 2869)"
This message can be cited
- GCN notice #2879
Paolo D'Avanzo, Stefano Ciroi, Daniele Malesani, Stefano Covino,
Vincenzo Testa, and Angelo Antonelli, report on behalf of a larger
Italian collaboration:
"We observed the field of GRB041218 (Mereghetti et al., GCN 2858)
starting about 6 hours after the trigger. Observations were performed
with the 182cm Copernicus telescope equipped with the AFOSC instrument,
at the Asiago Observatory (Northern Italy). Weather conditions were not
optimal, with a seeing of 3". We detected the optical afterglow in the R
filter (Torii, GCN 2860; Gorosabel et al., GCN 2861), with the following
magnitudes (based on the calibration provided by Henden, GCN 2869):
UT (mean) t-t0* mag error
-------------------------------
Dec 18.912 6.1 h 21.37 0.15
Dec 19.061 9.7 h 22.41 0.46
t0 = Dec 18.6565 UT (burst explosion time).
In the last epoch, the object is barely visible, but clearly faded since
the first epoch. Our results are consistent with those reported by Greco
et al. (GCN 2863), Halpern & Tuttle (GCN 2873) and Monfardini et al.
(GCN 2878). Using all the available data, the decay index is alpha ~ 1.4
(F=K*t^-alpha) from ~2 to ~13 hours after the GRB. When comparing with
the earliest measurement from Torii (GCN 2860), a steepening in the
light curve is apparent.
This message can be cited.
- GCN notice #2880
A. M. Soderberg (Caltech) reports on behalf of the Caltech/NRAO/Carnegie
GRB Collaboration:
"We observed the field of GRB 041218 (GCN #2858) with the VLA at
8.5 GHz on 2004 Dec 19.21 UT (t ~ 0.55 days). We do not detect
a radio counterpart to the optical afterglow reported by
Gorosabel (GCN #2861) and place an upper limit of
0.07 mJy at the optical afterglow position."
- GCN notice #2888
Kuntal Misra and S. B. Pandey (ARIES NainiTal), on behalf of
larger Indian GRB collaboration
We observed INTEGRAL GRB 041218 localization by Mereghetti et al. (GCN
2858) using 1.04m telescope at ARIES NainiTal, starting from Dec 19.66
UT. Several R_c band frames were observed in thin cloudy conditions.
In a 300sec x 5 averaged frame, we put an upper limit of ~ 21 mag around
1.0 day after the burst at the OT position by Torii K. (GCN 2860), in
comparison to the nearby stars using the field photometry by Henden
(GCN 2869).
This massage may be cited.
- GCN notice #2892
D.Yonetoku, T.Murakami, H.Masui and Kanazawa
GRB follow-up team report:
We observed the INTEGRAL GRB 041218 (Mereghetti et al. GCN #2858) using
the ISAS-Kanazawa automated 1.3m telescope at the roof top of the
Institute of Space and Astronautical Science (ISAS) in Sagamihara city.
The first observation started at 16:06:54 UT in a poor condition. The
stacked image of 30sx20 revealed a faint object with Rc=17.6 with an
error of 0.5 at the position reported by Torii and Gorosabel et al.
(GCNs # 2860, 2861). This was the first detection of this system with
a capability of R, J, H, K bands. Further analysis in progress.
This message may be cited.
- GCN notice #2897
P. Ferrero (IASF/CNR- Bologna/ Osservatorio e Universita' di Teramo),
G. Pizzichini (IASF/CNR- Bologna), G. Greco, C. Bartolini, A. Guarnieri,
and A. Piccioni(Universita' di Bologna), and R.Gualandi (INAF/ Bologna Observatory)
report:
We observed the optical afterglow of INTEGRAL GRB 041218 (Mereghetti et
al.,GCN 2858) detected by Torii (GCN 2860) and Gorosabel et al. (GCN
2861), using the 152 cm telescope in Loiano (Bologna University) on
December, 18 (Greco et al., GCN 2863) in clear sky conditions and strong
winds (seeing ~3).
Our photometric analysis of the images gives the following results:
----------------------------------------------------
Filter UT mean magOT exp
----------------------------------------------------
Rc Dec 18.758 19.74 +- 0.07 600s
Rc Dec 18.765 19.74 +- 0.06 600s
Rc Dec 18.781 20.04 +- 0.07 600s
Rc Dec 18.792 20.27 +- 0.07 600s
Rc Dec 18.800 20.58 +- 0.09 600s
Rc Dec 18.807 20.45 +- 0.09 600s
Rc Dec 18.814 20.64 +- 0.09 600s
Rc Dec 18.824 20.63 +- 0.09 600s
Rc Dec 18.840 20.81 +- 0.08 2x600s
Rc Dec 18.854 20.90 +- 0.10 2x600s
Rc Dec 18.872 20.75 +- 0.09 3x600s
V Dec 18.906 >19.1 (1 sigma) 600s
Rc Dec 18.913 >21 (1 sigma) 600s
B Dec 18.895 >20.4 600s
----------------------------------------------------
In the time interval of our observations we find the same decay index
alpha = 1.4 given by D'Avanzo et al., GCN 2879, with the possible
exception of the Rc magnitude at UT 18.872, which is however still within
3 sigmas of the extrapolation from the other points.
The following stars have been used:
R.A.: 24.853910 Decl.:+71.385923
R.A.: 24.801607 Decl.:+71.360825
R.A.: 24.831858 Decl.:+71.343547
for Rc photometry;
R.A.: 24.909680 Decl.:+71.278967
for V upper limit (Henden, GCN 2869);
R.A.: 24.903450 Decl.:+71.379872
for B upper limit (USNOA.2).
This message can be quoted.
- GCN notice #2904
GRB 041218: Optical observations
Klotz, A., Boer M. (OHP), Atteia, J.L., and G. Stratta (LATT) report:
The field of GRB 041218 (Mereghetti, et al., GCNC 2858) was observed with
the TAROT 25 cm robotic telescope at Calern, France.
The unfiltered observations started at 2004 December 18 17:12 UT (beginning
of the night). Due to a technical problem images were slightly defocused.
We co-added 129 frames of 30s from 17:12 to 18:50 UT.
The associated OT described by Torii (GCNC 2860) is detected 0.5 mag fainter
than the nearby star USNO-B1 1613-0027278.
Hence, we estimate its magnitude, R = 19.4 +/- 0.2.
We analyzed the 2MASS catalogue to extract the galactic extinction through
the line of sight of GRB041218. We used the method described in Klotz et al.
(A&A 2004, vol 425, p427). From Earth to a distance modulus of about 8, the
visual extinction is Av=1.45. The 2MASS data doesn't allow probing farer
distances.
This message can be cited.
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