Gamma-ray Burst 020305

(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:    Tue 05 Mar 02 21:51:55 UT
NOTICE_TYPE:    HETE Ground Analysis
TRIGGER_NUM:    1939,   Seq_Num: 3
GRB_DATE:       12338 TJD;    64 DOY;   02/03/05
GRB_TIME:       42925.05 SOD {11:55:25.05} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE:  7 sig/noise  on a 13.000 [sec] timescale
SC_-Z_RA:       166 [deg]
SC_-Z_DEC:        6 [deg]
WXM_CNTR_RA:   190.762d {+12h 43m 03s} (J2000),
               190.790d {+12h 43m 10s} (current),
               190.109d {+12h 40m 26s} (1950)
WXM_CNTR_DEC:  -14.552d {-14d 33' 06"} (J2000),
               -14.564d {-14d 33' 49"} (current),
               -14.278d {-14d 16' 41"} (1950)
WXM_MAX_SIZE:    50.00 [arcmin] diameter
WXM_LOC_SN:      5 sig/noise (pt src in image)
SUN_POSTN:      345.94d {+23h 03m 47s}   -6.01d {-06d 00' 35"}
SUN_DIST:       147.90 [deg]
MOON_POSTN:     246.27d {+16h 25m 05s}  -20.14d {-20d 08' 40"}
MOON_DIST:       53.02 [deg]
MOON_ILLUM:     56 [%]
GAL_COORDS:     299.88,48.27 [deg] galactic 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.

GCN notice #1261
P.A. Price and D.W. Fox (Caltech) with S. Pravdo, E. Helin, K. Lawrence, and M. Hicks of the NEAT/Palomar team report on behalf of the REACT GRB collaboration:
We have observed the error box of GRB 020305 / HETE #1939 with the Palomar 48-inch telescope + unfiltered CCD at two epochs. Exposures consisted of 6x120 sec at 2002 March 6.33 UT and 3x120 sec at March 6.47 UT (20 and 23.5 hours after the GRB respectively) each of which covered the entire error box to approximately the plate limit of the DSS (R ~ 20 mag). Apart from identifying several asteroids, we do not detect any variable object within the error box upon manual inspection of the subtracted images.
Further observations are planned.
This message may be cited.
GCN notice #1262
GRB020305 (=H1939): Localization of a GRB by HETE
G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team;
J. Villasenor, R. Vanderspek, G. Crew, J. Doty, G. Monnelly, N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, T. Donaghy, and C. Graziani, on behalf of the HETE WXM Team;
M. Boer, J-F Olive, J-P Dezalay, P. Lestrade, and K. Hurley on behalf of the HETE FREGATE Team;
write:
At 11:55:25.05 UTC (42925.05 s UT) on 5 March 2002, the HETE FREGATE and WXM instruments detected a GRB. The burst, H1939, was promptly reported as a GCN Alert Notice within 42 seconds of the detection time. The main part of the burst began at 11:59:04 UTC (43144 s UT), just as the spacecraft reached the dawn terminator and the WXM high voltage was turning off. Accurate aspect was derived for H1939 from a full data set on the ground. Ground analysis produced a location which can be expressed as a circle with a 90% confidence radius of 25 arcminutes centered at
```
     RA = +12h 43m 03s, Dec = -14d 33' 06" (J2000)
```
This location was reported in a GCN Alert Notice (issued at 5 Mar 2002 21:51:55 UT)
GRB020305 (=H1939) has a duration in the FREGATE 32-400 keV band of T90 = 252 seconds. In the 8-40 keV FREGATE band, the peak flux in 3 s was approximately 7 x 10-8 ergs cm-2 s-1 (i.e., approximately 2.5 x Crab flux). No duration or peak flux can be derived in the 2-25 keV WXM band because only the first 12 seconds of the main (second) peak were observed by the WXM before high voltage turnoff. The statistical significance of the burst in the 2-25 keV WXM band in this 12-second interval was 5 sigma.
Further information (including light curves) on GRB020305 is provided at the following URL: http://space.mit.edu/HETE/Bursts/
This message is citable.
GCN notice #1263
K. Hurley and T. Cline, on behalf of the Ulysses and HETE GRB teams;
G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team;
R. Vanderspek, G. Crew, J. Doty, G. Monnelly, J. Villasenor, N. Butler, T. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and HETE Optical-SXC Teams;
N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Donaghy, C. Graziani, and T. Tavenner, on behalf of the HETE WXM Team;
J-L Atteia, M. Boer, J-F Olive, P. Lestrade, and J-P Dezalay, on behalf of the HETE FREGATE Team;
report:
Ulysses observed GRB020305 (=H1939). As observed by both Ulysses and FREGATE, this event consists of two distinct episodes of emission separated by an ~ 200 s long quiescent period, raising the question of whether both episodes are from the same source. As the Ulysses and FREGATE time histories are identical to within statistics, we conclude that both episodes indeed had the same origin, and that the duration of this event is therefore ~280 s.
As observed by Ulysses, the 25-100 keV fluence and peak flux over 0.5 s are ~7x10^-6 erg cm^-2 and 4.7 x 10^-7 erg cm^-2 s^-1. Triangulation using the FREGATE data gives an annulus centered at RA(2000)= 71.966 deg., Decl.(2000)= -81.411 deg., with radius 79.798 +/- 0.180 deg. (3 sigma). The center line of this annulus passes ~0.1 degrees from the center of the HETE WXM error circle, and the annulus intersects the error circle at:
```
  RA(2000)   Dec(2000)

  191.118     -14.317
  190.483     -14.235
  191.169     -14.687
  190.332     -14.578
```
The combined annulus/error circle has an area approximately 2.4 times smaller than the error circle alone, or approximately 800 square arcminutes. A plot has been posted at ssl.berkeley.edu/ipn3/020305.
GCN notice #1264
J. Moran, M. Nysewander, K. Shella, C. Yeates, J. Rose, W. Christiansen (UNC-CH), and D. Reichart (Caltech) report:
We observed the central 30 arcmin x 30 arcmin of the 50 arcmin diameter error circle of GRB 020305 (HETE 1939) with the Morehead Observatory 0.6 m telescope beginning ~ 16 hours after the burst.
Visual comparison with the DSS reveals no new sources down to R ~ 18 and V ~ 17.
GCN notice #1265
M. Jelinek, P. Kubanek, M. Nekola, R. Hudec & BART team, Astronomical Institute, Academy of Sciences of the Czech Republic, Ondrejov, report:
The BART robotic telescope at the Ondrejov Observatory observed the error box of the GRB020305 (HETE trigger 1939) at March 5.93249 UT i.e. 10.45 hours after the burst.
Observation was done by two different cameras in six groups of eleven (pairs of) images, with 120s exposures. Every group of images took approx. 35 minutes (0.02430d) to obtain. Series were beginning at: 2002 March 5.93249, 5.96767, 6.01779, 6.06597, 6.11422 and 6.16356 UT.
The observing conditions were not optimal due to some sort of cirrus on the sky.
No new optical object was found in reported error box.
Following magnitude limits were obtained:
Wide Field Camera (D=64mm, f/1.7), unfiltered, full HETE error box coverage, gives single image limiting magnitude 14.5 in 2 minute integration.
Narrow Field Camera (D=254mm, f/6.3), Johnson R-band, single-image limiting magnitude 17.0, when combining all 66 obtained NF images there is a limiting magnitude of 18.5 with effective integration time of 132 min. The Narrow Field Camera FOV is 20 x 20 arcmin (~ 20% of the HETE and ~50% of the combined HETE/IPN error box) centered approx 7 arcmin to the west and 4 arcmin to the south from the center of the HETE reported position (the image center has RA12:42:30, DEC -14:37).
Further image analysis is planned.
GCN notice #1267
P.A. Price, D.W. Fox (Caltech) report on behalf of the REACT GRB Collaboration:
We have observed the error box of GRB 020305 (GCN ##1262,1263) with the Palomar 48-inch + unfiltered CCD at 2002 Mar 9.34. Our 7 x 120 sec exposures cover the entire IPN+HETE error box. PSF-matched image subtraction of our combined image from Mar 6.33 (GCN #1261) reveals the presence of a point-like source that was present on Mar 6 and not detected on Mar 9 to a limiting magnitude of R ~ 21.5 mag. The source is not present on the DSS. Coordinates of the source are:
```
	RA: 12:42:27.94   DEC: -14:18:11.8   J2000
```
with an estimated uncertainty of approximately 1 arcsec.
Further observations are underway to ascertain the veracity of this afterglow candidate.
This message may be cited.
GCN notice #1270
D.W. Fox, P.A. Price (Caltech) and J. Darling (Cornell) report on behalf of the REACT GRB Collaboration:
We have observed the afterglow candidate of GRB 020305 (GCN #1267) with the Palomar 200-inch telescope + COSMIC re-imager at 2002 Mar 13.8 UT. Our exposures consisted of 3x600 sec images in Gunn-i. The afterglow candidate is well detected in the combined image, with an estimated magnitude of R ~ 22.1 mag. Since this value is little different from our upper limit from Mar 9, this source may be the quiescent component (host galaxy?). Due to the large error box, we cannot as yet rule out the possibility that this object is unrelated to the GRB.
Further observations are planned.
This message may be cited.
GCN notice #1271
Y. Ohyama, M. Yoshida, K. S. Kawabata, Y. Saito, A. D. Saga, and S. Harasawa
```
          on behalf of the FOCAS Team:
```
G. Kosugi, Y. Mizumoto, M. Iye, R. Ogasawara, T. Takata, K. Sekiguchi, T. Yamada, N. Kobayashi, J. Watanabe, T. Totani, A. Yoshida, N. Kawai, Y. Urata, T. Tamagawa, K. Torii, J. Noumaru, Y. Komiyama, W. Aoki, and K. Motohara on behalf of the Subaru GRB Team:
We have observed the afterglow candidate of GRB 020305 (GCN #1267) with the Subaru 8.2m telescope atop Mauna Kea at 2002 March 12.6 UT (7 days after the burst). Several R and I-band images were taken with the observing instrument FOCAS. The limitting magnitudes were approximately R=26 and I=25, respectively.
We detected a point source of R=22.6 and I=22.1 within 1 arcsec from the position reported in GCN #1267. 7 USNO stars were used for R-band relative photometry. The magnitude in I-band, however, was estimated by simply converting the observed intensities empirically to the magnitude. Elongated diffuse nebulosity can be seen toward the northeast direction from the candidate.
R and I-band images may be found at: http://www.naoj.org/staff/george/Distribute/GRB020305/GRB020305.html
This message may be cited.
GCN notice #1275
B. C. Lee, D. Q. Lamb, D. L. Tucker, D. E. Vanden Berk, J. Krzesinski, D. Long, P. R. Newman, A. Nitta, and S. A. Snedden, on behalf of the SDSS GRB team, report:
We observed the field of GRB020305 (= H1939) (Ricker et al., GCN 1262) using the SDSS 0.5-m "Photometric Telescope" (PT) at APO under partly cloudy conditions beginning at UTC 2002 March 6.33 (20 hours after the GRB). We obtained three sets of three 400-second g'-band, r'-band, and i'-band exposures (41.5' x 41.5' field of view) centered on the reported best-fit location of GRB020305 (Ricker et al., GCN 1262). These exposures covered the entire combined HETE/IPN error box for the burst (Hurley et al., GCN 1263).
Co-adding the images taken in each filter, we find an object with estimated magnitudes of g* = 20.3 +/- 0.5, r* = 20.1 +/- 0.5, and i* = 19.8 +/- 0.5, within 1 arcsec the location of the candidate optical afterglow reported by Price et al. (GCN 1267). These errors are conservative, and reflect the fact that we do not yet fully understand our systematics. The magnitudes we measure are consistent with a power-law spectrum having a slope of roughly -1, which is typical of GRB afterglows. Combining our results with the limiting magnitude of R ~ 21.5 at UTC 2002 Mar 9.34 reported by Price et al. (GCN 1267) and the magnitudes of R = 22.6 and I = 22.1 at UTC 2002 Mar 12.6 reported by Ohyama et al. (GCN 1271), we find that the candidate afterglow faded between UTC 2002 Mar 6.33 and Mar 12.6 at a rate that is consistent with a temporal slope of roughly -1.3, which is also typical of GRB afterglows. Thus both the spectral and temporal behavior of the candidate afterglow identified by Price et al. (GCN 1267) support its identification as the optical afterglow of GRB020305.
This message may be cited.
GCN notice #1279
M. Lopez-Morales, J. C. Clemens (UNC-CH), and D. E. Reichart (Caltech) report:
On March 5, we observed the entire 50 arcmin diameter error circle of GRB 020305 (HETE 1939; GCN 1262) with the automated 8" Pisgah Survey Telescope at PARI (Pisgah Astronomical Research Institute) in Rosman, North Carolina. Observations began 15.8 hours after the burst. Visual comparison with the DSS revealed no new sources at that time.
At the location of the candidate afterglow (GCN 1267), we are partially contaminated by light from a nearby, bright (I = 14.7 +- 0.1 mag) star. Consequently, we reimaged the field on March 15. Comparison of aperture photometry between the two epochs allows us to place the following limits at the location of the candidate afterglow on March 5: I > 17.6 mag (1 sigma), I > 16.8 mag (2 sigma), and I > 16.4 (3 sigma).
GCN notice #1283
I. Burud, J. Rhoads, A. Fruchter, D. Griep
We observed the location of the candidate OT of GRB020305 on 2002 March 13.43 and 14.39 in the K' filter with the NASA IRTF + NSFCam. A source is found at the location of the afterglow reported by Price et al. (GCN 1267) with estimated magnitudes K' = 19.7 and K'=19.8 on March 13.43 and March 14.39 respectively. The photometric uncertainty is estimated to be 0.2 mag. For the star U0750_07926230 located 7.5 arcsec South and 12.1 arcsec East of the OT we measure a magnitude K'= 13.53 +/- 0.04.
GCN notice #1302
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:
We have acquired BVRcIc all-sky photometry for an 11x11 arcmin field in the error box for GRB020305 (Ricker et al. GCN 1262; Hurley et al. GCN 1263) with the USNOFS 1.0-m telescope on one marginally photometric night. The field is approximately centered on the position of the candiate optical transient reported by Price et al. (GCN 1267). Stars brighter than V=13.5 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/grb020305.dat. The conditions were basically clear, but early evening clouds prevented field acquisition until it was near airmass 2.0. For that reason, there is a slight possibility that the photometry has larger than the expected 0.02mag external error, but all tests (such as color consistency) seem reasonable. The astrometry in this file is based on linear plate solutions with respect to USNO-A2.0. The internal errors are less than 100mas.
Note that the source mentioned in GCN 1267 is near the northwestern edge of the error circle, and so the current field photometry does not do a good job of calibrating small-field images centered on the error circle. We intend to take another shallower dataset in the near future centered at the HETE coordinates.
GCN notice #1542
J. Gorosabel (IAA-CSIC), J. Fynbo (Univ. of Aarhus), I. Burud (STScI), A. Fruchter (STScI), J. Hjorth (Univ. of Copenhagen), report for the larger GOSH (GRB Optical Studies with HST) collaboration:
We have observed the position of the optical afterglow (GCN 1267) of GRB 020305 (GCN 1262) with HST/STIS. The GRB field was visited four times; on April 12.7-12.9 UT (Clear filter), April 14.1-14.4 UT (Long-Pass), June 16.4-16.5 UT (Clear filter), and June 16.6-16.8 UT (Long-Pass).
Subtraction of the two epoch HST/STIS images taken for each filter reveals a fading point source. The centroids of the Long-Pass and Clear filter residuals are consistent with the afterglow position independently derived registering an afterglow NOT image (taken on March 16) on our HST/STIS frames.
The magnitudes of the afterglow (AB system) are: 24.693+/-0.008 (Clear, April 12.7-12.9 UT), 24.452+/-0.013 (Long-Pass, April 14.1-14.4 UT), 26.197+/-0.027 (Clear, June 16.4-16.5 UT) and 25.951+/-0.047 (Long-Pass, June 16.6-16.8 UT). The decay indexes associated to the Clear and Long-Pass filters are, respectively; Alpha_Clear = 1.40+/-0.03, Alpha_Long-Pass = 1.45+/-0.05. So, the optical decay is consistent with being achromatic.
The afterglow position is consistent with an extended (~1.2"x0.5") faint galaxy which shows a complex morphology. A preliminary aperture photometry (AB system, considering a 0.675" aperture radius and the corresponding aperture correction) of the whole host galaxy system yields 25.771+/-0.054 (Clear filter) and 25.464+/-0.087 (Long-Pass filter), respectively.
Several gifs of the HST/STIS images and the afterglow light curve can be seen at:
http://www.stsci.edu/~fruchter/GRB/020305/
The optical measurements reported to date (our HST/STIS data points and the ones given in the GCNs; 1264, 1265, 1267, 1270, 1271, 1275, 1279, 1283) might suggest the presence of a break ~10 days after the burst. However, a final confirmation would require a more careful analysis.
A&A 437, 411 (2005): Gorosabel et al:
A possible bright blue SN in the afterglow of GRB 020305
Abstract: We report on ground-based and HST(+STIS) imaging of the afterglow and host galaxy of the Gamma-Ray Burst (GRB) of March 5 2002. The GRB occurred in a R=25.17+/-0.14 galaxy, which apparently is part of an interacting system. The lightcurve of the optical afterglow shows a rebrightening, or at least a plateau, 12--16 days after the gamma-ray event. UBVRIK' multi-band imaging of the afterglow ~12 days after the GRB reveals a blue spectral energy distribution (SED). The SED is consistent with a power-law with a spectral index of \beta=-0.63+/-0.16, but there is tentative evidence for deviations away from a power-law. Unfortunately, a spectroscopic redshift has not been secured for GRB020305. From the SED we impose a redshift upper limit of z ~< 2.8, hence excluding the pseudo redshift of 4.6 reported for this burst. We discuss the possibilities for explaining the lightcurve, SED and host galaxy properties for GRB 020305. The most natural interpretation of the lightcurve and the SED is an associated supernova (SN). Our data can not precisely determine the redshift of the GRB. The most favoured explanation is a low redshift (z~0.2) SN, but a higher redshift (z>0.5) SN can not be excluded. We also discuss less likely scenarios not based on SNe, like a burst occurring in a z=2.5 galaxy with an extinction curve similar to that of the Milky Way.

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Jochen Greiner, last update: 10-Jul-2005 [Disclaimer]