Gamma-ray Burst 050209

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE


TITLE:          GCN/HETE BURST POSITION NOTICE
NOTICE_DATE:    Wed 09 Feb 05 03:55:21 UT
NOTICE_TYPE:    HETE Ground Analysis
TRIGGER_NUM:    11568,   Seq_Num: 1
GRB_DATE:       13410 TJD;    40 DOY;   05/02/09
GRB_TIME:       5501.49 SOD {01:31:41.49} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
SC_-Z_RA:       322 [deg]
SC_-Z_DEC:      -17 [deg]
SC_LONG:        258 [deg East]
WXM_CNTR_RA:    126.537d {+08h 26m 09s} (J2000),
                126.611d {+08h 26m 27s} (current),
                125.816d {+08h 23m 16s} (1950)
WXM_CNTR_DEC:   +19.684d {+19d 41' 02"} (J2000),
                +19.667d {+19d 40' 01"} (current),
                +19.848d {+19d 50' 54"} (1950)
WXM_MAX_SIZE:   14.00 [arcmin] diameter
WXM_LOC_SN:     16 sig/noise (pt src in image)
WXM_IMAGE_SN:   X= 14.0 Y= 6.0 [sig/noise]
WXM_LC_SN:      X= 25.5 Y= 18.0 [sig/noise]
SUN_POSTN:      322.80d {+21h 31m 12s}  -14.69d {-14d 41' 14"}
SUN_DIST:       163.76 [deg]
MOON_POSTN:     326.17d {+21h 44m 41s}  -18.28d {-18d 16' 38"}
MOON_DIST:      161.46 [deg]
MOON_ILLUM:     0 [%]
GAL_COORDS:     204.53,29.35 [deg] galactic lon,lat of the burst
ECL_COORDS:     124.10,0.46 [deg] ecliptic lon,lat of the burst
COMMENTS:       Definite GRB.
COMMENTS:       WXM error box is circular; not rectangular.
COMMENTS:       Burst_Validity flag is true.
COMMENTS:       WXM data refined since S/C_Last Notice.

red DSS finding chart ps-file
GCN notice #3012
K. Torii (Osaka U.) reports:
The entire error region of GRB050209 (HETE trigger #11568) was observed with 0.3-m remote telescope in the New Mexico Skies Observatory. The imaging started at 03:57 UT and 120-s exposures in I-band was repeated. As a result of the preliminary analysis, we do not identify a new object brighter than 17 mag (120s x 5 frames, USNO-A2.0 R magnitude).
GCN notice #3013
GRB050209 (=U11568): A Long GRB Detected by HETE
N. Kawai, G. Ricker, J-L. Atteia, D. Lamb, and S. Woosley, on behalf of the HETE Science Team;
T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, M. Matsuoka, Y. Nakagawa, T. Sakamoto, R. Sato, Y. Shirasaki, M. Suzuki, T. Tamagawa, Y. Urata, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the HETE WXM Team;
N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek, J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
M. Boer, J-F Olive, J-P Dezalay, and K. Hurley, on behalf of the HETE FREGATE Team;
report that:
Post-processing analysis of HETE data has revealed the presence of GRB 050209, an untriggered GRB (=U11568) detected as HETE was entering the SAA. The burst was detected at 01:31:41 UT and had a duration of approximately 40 seconds. The GRB has been localized to a circle of radius 7' (90% confidence) centered at:
RA = 08h 26m 09s, DEC = +19d 41m 02s (J2000).
Light curves in four spectral bands and a skymap for GRB 050209 are provided at the following URL:
http://space.mit.edu/HETE/Bursts/GRB050209
Because of the proximity of the SAA, extraction of spectral data requires manual processing, and will be provided in a follow-up GCN Circular.
This message may be cited.
GCN notice #3014
S. Bradley Cenko and Derek B. Fox report on behalf of the Caltech-NRAO-Carnegie GRB collaboration:
We have imaged the full error circle of GRB050209 (HETE 11568, GCN 3013) with the automated Palomar 60-inch telescope. Observations commenced approximately 6 minutes after receiving the HETE trigger. We have obtained two epochs of coverage in the Kron R filter at median epochs of approximately 4:15 UT (2.7 hours after the burst) and 6:00 UT (4.5 hours after the burst).
In the first epoch, we find no new source by comparison with the Digitized Sky Survey to a limiting magnitude of R ~ 20.5 (magnitudes calculated with reference to the Guide Star Catalog). Visual comparison between our two epoch shows no sign of any fading sources in the field.
We also note the presence of a minor planet, 1998 WB7, about to enter the HETE error circle at the time of our second epoch.
Further observations are planned.
GCN notice #3015
G.Bourban, C.Vuissoz, F.Carrier, G.Burki and L.Weber (Geneva Observatory, Switzerland) report:
We have carried out optical observations of the 12'x 12' field centered on the error circle of HETE trigger #11568 (~93% of the whole uncertainty area provided by HETE/WXM) using the C2 CCD Camera mounted on the Swiss 1.2-meter telescope located at the ESO La Silla Observatory (Chile). The observations began on 2005 Feb 09 at 03:57:30 UT (129s after the alert sent by HETE team, i.e 2.43 h after the burst) and four different sets of measurements were performed during the night at 03:57 UT, 04:57 UT, 06:07 UT and 07:12 UT (1.5 < Fz < 2.7). A total of 3 R-filtered images with exposure time of 180s as well as 8 R-filtered 480s exposures were obtained under good wheather conditions.
The division of these images as well as their comparison with the USNO-A2 catalog did not reveal any new or fainting source inside the field of view of the C2 camera, down to a limiting magnitude of R < 20.5.
This message may be cited.
GCN notice #3016
Y. Yatsu, M. Arimoto and N. Kawai (Tokyo Tech) report on behalf of MITSUME collaboration,
"We observed the field covering the entire error circle of GRB050209 (GCN 3013, Kawai et al.) with the 50 cm Mitsume Telescope at Akeno, Japan in I band starting at 10:07 UT for 25 min.
Co-adding 49 frames of 30 sec exposure, we detected no new objects down to a limiting magnitude of I=18.6."
GCN notice #3017
P. D'Avanzo, A. Melandri, S. Covino, E. Palazzi, V. Testa, F. D'Alessio, D. Malesani, L. A. Antonelli, F.M. Zerbi, G. Tosti, A. Monfardini, L. Nicastro, G. Chincarini, M. Rodono', G. Cutispoto, E. Molinari, F. Vitali, on behalf of the REM/ROSS Team report:
"We imaged the field of GRB050209 (HETE 11568: Kawai et al, GCN 3013) with the robotic 60cm REM telescope located in La Silla (Chile) starting observations 24 seconds just after received the trigger through GCN Notice.
Observations were performed in fully automated mode with the REM Optical Slitless Spectrograph (ROSS) in the V, R and I filters (REM IR camera was in manteinance). Oservation started on 2005 Feb 09.163 UT, approximately 2.4 h after the GRB. The field was imaged in each filter for a total exposure time of 400s, under good seeing conditions.
No new sources are detected within the HETE error circle by comparison with the Digitized Sky Survey, down to a limiting magnitude V=19.1, R=19.1, I=18.5 (5-sigma confidence).
This message is citeable."
GCN notice #3019
GRB 0050209(=3DU11568): Duration and spectrum
D. Lamb, G. Ricker, J-L. Atteia, N. Kawai, and S. Woosley, on behalf of the HETE Science Team;
T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, M. Matsuoka, Y. Nakagawa, T. Sakamoto, R. Sato, Y. Shirasaki, M. Suzuki, T. Tamagawa, Y. Urata, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the HETE WXM Team;
N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek, J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
M. Boer, J-F Olive, J-P Dezalay, and K. Hurley, on behalf of the HETE FREGATE Team;
report:
The T_50 durations for GRB 050209 are approximately 16, 17, and 15 s in the 6-40, 6-80 and 30-400 keV energy bands, respectively; the T_90=20 durations for the burst are approximately 36, 41, and 46 s in the same energy bands.
The spectrum of GRB 050209 evolves strongly from hard to soft during the burst. Ground analysis of the FREGATE and WXM spectral data show that the average spectrum of the burst is adequately fit by a single power-law with index alpha =3D - 1.7 =B1 0.07 in the 2-400 keV energy band, implying that E_0 lies near or above 400 keV and E_peak lies above 120 keV. The fluences in the 2-30 keV and 30-400 keV energy bands are 1 x 10-6 and 2 x 10-6 erg cm-2, respectively; the fluence in the 2-400 keV energy band is therefore 3 x 10-6 erg cm-2. The fluence ratio=20 S(2-30 keV)/S(30-400 kev) =3D 0.33. Technically, this makes GRB 050209=20 an "X-ray rich" burst, despite the relatively high value of E_peak. =20 This is due to the steepness of the low-energy power-law index alpha.=20 Because we are only able to place a lower bound on E_peak, we can only place a lower limit on the pseudo-redshift for this burst of about 2.
A light curve, skymap, and some spectral information for GRB 050209 are provided at the following URL: http://space.mit.edu/HETE/Bursts/GRB050209
This message may be cited.
GCN notice #3020
Alain Klotz (CESR-OHP), and Michel Boer, (OHP) on behalf of the TAROT team report:
"We imaged the entire field of GRB 050209 with the TAROT robotic telescope located at the Calern observatory, France. Observations started 26 seconds after the receipt of the GCN notice, i.e. approx. 2h25 after the event. The position was at an elevation of 22 degrees above the western horizon. No new source was detected after a comparison with the USNO A2-0 catalogue. From a frame to frame study no decaying source was found. We co-added 84 30s images: we reach a limiting R magnitude of 19.2.
A summary of the data, as well as TAROT images can be found at the following URL: http://www.cesr.fr/~klotz/grb050209/
This message is citable.

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Jochen Greiner, last update: 12-Feb-2005 [Disclaimer]