//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 959 SUBJECT: ALERT: GRB010222: the brightest GRB observed by BeppoSAX DATE: 01/02/22 10:36:47 GMT FROM: Luigi Piro at IAS/CNR Frascati On Feb. 22, 07:23:30 U.T. a very bright GRB, possibly the brightest ever observed by BeppoSAX has been detected simultaneously by the GRBM and WFC1 aboard BeppoSAX. Preliminary coordinates from WFC are: R.A.(2000)= 223.069 DEC.(2000)= 43.035 The error radius at this stage of analysis is 5'. We are planning a BeppoSAX-NFI observation. Luigi Piro BeppoSAX Mission Scientist [GCN OPS NOTE (22feb01): There was a typo in the date_name for this burst in the Subject-line in the original distribution. This Circular is really about GRB 010222, not 020223.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 960 SUBJECT: GRB010222: BeppoSAX refined position DATE: 01/02/22 11:39:13 GMT FROM: Luigi Piro at IAS/CNR Frascati GRB010222: BeppoSAX refined position Refined coordinates of GRB010222 from BeppoSAX WFC are: R.A.(2000)= 223.051 DEC.(2000)= 43.012 The error radius at this stage of analysis is 2.5'. Please note that in GCN 959 the burst has been named GRB020223 instead of GRB010222 due to a trivial typo. G. Gandolfi on behalf of BeppoSAX Mission Scientist //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 961 SUBJECT: GRB010222 DATE: 01/02/22 11:48:59 GMT FROM: Arne A. Henden at USNO/USRA A. Henden, on behalf of the USNO GRB team, reports: A possible optical transient has been detected in the SAX error box (GCN 960). It is about 18th magnitude in V. The coordinates are: 223.05238 43.01844 15:45:04.4 +43:04:01 +/- 1arcsec Observations continue. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 962 SUBJECT: GRB010222 DATE: 01/02/22 11:58:24 GMT FROM: Arne A. Henden at USNO/USRA Sorry, early hours here. Sexagesimal coordinates: 14:52:12.0 +43:01:06 J2000 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 963 SUBJECT: GRB010222: possible optical counterpart DATE: 01/02/22 13:12:07 GMT FROM: Krzysztof Z. Stanek at CfA J. McDowell, R. Kilgard (Harvard-Smithsonian CfA), P. M. Garnavich (Notre Dame), K. Z. Stanek and S. Jha (Harvard-Smithsonian CfA) report: We have an independent detection of a new source in the revised SAX error box (GCN 960). Its position, based on the GSC, agrees with that of Henden (GCN 962): 14:52:12.55 43:01:06.26 (J2000). Comparing to star "A" (R=17.0) from the USNO catalog (located at 14:52:07.55 42:58:48.66), we estimate the R-band magnitude of the possible GRB010221 afterglow to be R=18.4\pm 0.1. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 965 SUBJECT: Redshift of the Optical Transient of GRB010222 DATE: 01/02/22 18:45:01 GMT FROM: Krzysztof Z. Stanek at CfA P. M. Garnavich (Notre Dame), M. A. Pahre, S. Jha, M. Calkins, K. Z. Stanek, J. McDowell and R. Kilgard (Harvard-Smithsonian Center for Astrophysics) report: A spectrum of the optical transient (GCN 961, 962, and 963) associated with GRB010222 (GCN 959, 960) was obtained with the F. L. Whipple Observatory 1.5m Tillinghast telescope (+ FAST spectrograph) on 2001 February 22 beginning at UT 12:18, 4.92 hours after the burst. Two 1200s spectra were obtained with a 3 arcsec wide slit and 300 l/mm grating, yielding 6 Angstrom resolution over the range from 3620 to 7560 A. The OT was approximately R=18.4 mag around the time of the spectroscopy (GCN 963). This spectrum shows a blue continuum and many narrow absorption lines with the following preliminary identifications: Observed Line Rest Redshift Wavelength ID Wavelength (angstrom) (angstrom) 6405.9 FeII 2585.4 1.477 6438.7 FeII(UV1) 2598.4,2599.4 1.477 6924.2 MgII 2796 1.476 6941.6 MgII 2803 1.476 The FeII (2585,2599) and MgII (2796,2803) doublet absorption features are strong, absorbing approximately 50 and 80% of the continuum at those wavelengths. These absorption lines constrain the redshift of the optical transient associated with GRB010222 to be at >= 1.476. If the lines come from a host galaxy associated with the GRB, then the redshift is 1.476. Additional unidentified absorption lines appear in the spectrum, data analysis is continuing. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 966 SUBJECT: GRB010222: BeppoSAX/NFI Observations DATE: 01/02/22 20:12:16 GMT FROM: Luigi Piro at IAS/CNR Frascati GRB010222: BeppoSAX/NFI Observations A BeppoSAX TOO observation of GB010222 has started about 9 hours after the GRB. A preliminary analysis of MECS(1.6-10 keV) image of the first orbit shows a bright unknown source in the WFC error circle. The position is: RA(2000) = 223.052 Delta(2000) = 43.012 The error radius is 1 arcminute. This source is consistent with the detected optical transient (GCN 962 and 963). G. Gandolfi on behalf of BeppoSAX Mission Scientist [GCN OPS NOTE(22feb01): A typo was corrected. The phrase "...of GB010214 has started..." was changed to "...of GB010222 has started...".] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 967 SUBJECT: GRB010222, optical observations DATE: 01/02/22 21:04:26 GMT FROM: Arne A. Henden at USNO/USRA A. Henden (USRA/USNO) and F. Vrba (USNO), on behalf of the USNO GRB team and a larger European GRB collaboration, report: We observed the BeppoSAX error box for GRB010222 (GCN 959, 960, 966) with the USNOFS 1.0-m telescope under cloudy conditions. The discovery of the optical transient for this burst was given in Henden (GCN 961, 962). The final astrometry for the OT, relative to USNO-A2.0, is 223.05229 43.01840 14:52:12.55 +43:01:06.2 (J2000) with internal errors of 0.2arcsec. This is in agreement with the values given in McDowell et al. (GCN 963). A finding chart (R-band, 4.5x4.5arcmin, NE=upperleft) is given at ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb010222r.jpg BVRcIc frames were taken shortly after the localization posting. However, only the preliminary R-band measures are reported here. The quality of the photometry suffered due to the thick clouds, but is good enough to show definite fading of the transient: UT exp Rc err 010222.486 1x300 18.36 0.059 010222.510 2x300 18.52 0.054 010222.518 2x600 18.68 0.059 010222.533 2x600 18.67 0.057 Where the R-band magnitudes are relative to the bright USNO-A2.0 star (identified as "A" on the finding chart) at J2000 coordinates 14:52:14.80 +43:01:40.9 and that has an assumed magnitude R=14.70. More careful all-sky calibration of this field will be performed on the next few nights. The intent is to only calibrate in BVRcIc; please contact Henden if you need U-band calibration as well. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 968 SUBJECT: GRB010222, radio observations DATE: 01/02/22 21:13:28 GMT FROM: Dale A. Frail at NRAO E. Berger (Caltech) and D. A. Frail (NRAO) report on behalf of a larger collaboration: "On 2001 February 22.62 UT we used the VLA to observe a field centered at the position of the optical transient reported by Henden (GCN#961,GCN#962) in the error circle of GRB010222 (GCN#959, GCN#960). At 22 GHz we detect a radio source coincident with the optical source. A preliminary reduction gives a flux of 0.70+/-0.15 mJy. Further observations are planned." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 969 SUBJECT: GRB010222: Optical Observations DATE: 01/02/22 21:44:41 GMT FROM: AAVSO GRB Network at AAVSO The American Association of Variable Star Observers (AAVSO) reports on behalf of Gary Billings, a member of the AAVSO International GRB Network, imaging of the optical transient of GRB010222 (GCN 959,960) at the location given by Henden et al. (GCN 961, 962) and confirmed by McDowell et al. (GCN 963). Astrometry on the suspected GRB (using Astrometrica + USNO A2.0) gives RA 14 52 12.6 and Dec 43 01 06, with errors of about 0.5" on each axis, consistent with the measures given in McDowell et al. (GCN 963) and Henden et al. (GCN 967). Images of the possible detection can be downloaded from the following URLs: ftp://ftp.aavso.org/grb/grb010222-billings-a.fit -- shot between 1136 UT and 1229 UT (22 Feb 2001), sum of 28 V-band exposures of 90 seconds. ftp://ftp.aavso.org/grb/grb010222-billings-b.fit -- shot between 1241 and 1333 UT (22 Feb 2001), sum of 31 V-band exposures of 90 seconds. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 970 SUBJECT: GRB010222: R-band fading behavior DATE: 01/02/22 21:54:46 GMT FROM: Krzysztof Z. Stanek at CfA K. Z. Stanek, S. Jha, J. McDowell, R. Kilgard, J. Roll (Harvard-Smithsonian CfA), P. M. Garnavich (Notre Dame) and J. Kaluzny (Copernicus Astronomical Center) report: R-band observations of the optical afterglow of the GRB010222 carried out with the F. L. Whipple Observatory 1.2m telescope, starting at UT 11:10 (3.8 hours after the burst), indicate a fading behavior of the source at 14:52:12.55 +43:01:06.2 (J2000): HJD-2450000 UT R_c exp 1962.9610 010222 11:10 18.18+-0.02 600 sec 1962.9695 010222 11:23 18.21+-0.02 600 sec 1963.0106 010222 12:22 18.36+-0.02 600 sec Errors in the magnitudes are statistical only. The R-band magnitudes are relative to star "A" as marked in the finding chart at http://cfa-www.harvard.edu/cfa/oir/Research/GRB/, assuming its magnitude R=17.0 (see GCN 963). Our comparison star is different from the star "A" of Henden & Vrba (GCN 967), which is saturated in our images. These data should not be combined with that of Henden & Vrba unless using common comparison stars. We have also obtained UBVI observations of the afterglow, reductions of which are under way. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 971 SUBJECT: GRB010222: Sub-millimeter detection DATE: 01/02/22 22:31:31 GMT FROM: Ian Smith at Rice U Michel Fich (U. Waterloo), Robin R. Phillips, Gerald Moriarty-Schieven, Remo P.J. Tilanus (JAC), Dale A. Frail (NRAO), and Ian Smith (Rice U.) report on behalf of the Dutch and Canadian GRB collaborations: "We used the SCUBA sub-millimeter continuum bolometer array on the JCMT to observe the optical (GCN #962, 963, 965) and radio counterpart (GCN #968) to GRB 010222 between 13:03 and 18:16 on 2001 February 22 UT. We detect a source at this location with a preliminary averaged 850 micron flux density of 4.2 +/- 1.2 mJy." Further observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 973 SUBJECT: GRB010222: Optical decay slope DATE: 01/02/23 01:23:59 GMT FROM: Paul Price at RSAA, ANU at CIT P.A. Price (Caltech), A. Gal-Yam, E. Ofek (Wise Observatory), S. Yost, J.S. Bloom, T.J. Galama F. Harrison and S.R. Kulkarni (Caltech) report on behalf of a larger collaboration: "A. Gal-Yam and E. Ofek have observed the optical afterglow of GRB 010222 (GCN #961, #962) with the Wise 1-metre telescope in R-band at Feb 22.95 UT. Preliminary photometry on the unflattened images against comparison star `A' of Henden (GCN #967) yields a magnitude of R = 19.623 +/- 0.12 mag. When combined with the data from Henden (GCN #967), we derive a temporal decay slope of alpha = 0.89 +/- 0.09. The results of the proper reduction will follow later. We report this now in order to assist those preparing observations." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 974 SUBJECT: GRB010222: Another absorption line system DATE: 01/02/23 05:14:40 GMT FROM: Saurabh Jha at Harvard-Smithsonian CfA S. Jha, T. Matheson, M. Calkins, M. A. Pahre, K. Z. Stanek, J. McDowell, R. Kilgard (Harvard-Smithsonian CfA), and P. M. Garnavich (Notre Dame) report: Further reduction and analysis of the FLWO 1.5m spectrum of the GRB 010222 optical afterglow (GCN 965) reveals the presence of two absorption systems along the line of sight to the gamma-ray burst, one at z = 1.477 as reported, and another with weaker lines at z = 1.157. The interstellar absorption lines observed from each system are as follows, with identifications based on the ultraviolet spectral atlas of Blades et al. (1988, ApJ, 334, 308): Observed Line Rest Redshift Wavelength Identification Wavelength (A) (A) 7065.4 Mg I 2852.1 1.477 6941.7 Mg II 2802.7 1.477 6924.0 Mg II 2795.5 1.477 6438.5 Fe II 2599.4 1.477 6422.4 Mn II 2593.7 1.476 6405.4 Fe II 2585.9 1.477 6381.2 Mn II 2576.1 1.477 5900.1 Fe II 2382.0 1.477 5879.6 Fe II 2373.7 1.477 5805.4 Fe II 2343.5 1.477 5108.5 Zn II/Cr II blend 2061.9 1.478 5018.5 Zn II/Mg I blend 2025.6 1.478 4478.9 Si II 1808.0 1.477 4137.8 Al II 1670.8 1.477 3838.0 C IV blend 1549.0 1.478 3781.8 Si II 1526.7 1.477 6045.0 Mg II 2802.7 1.157 6028.2 Mg II 2795.5 1.156 5606.7 Fe II 2599.4 1.157 5574.1 Fe II 2585.9 1.156 5137.2 Fe II 2382.0 1.157 This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 975 SUBJECT: GRB 010222, Decay Slope Confirmed DATE: 01/02/23 07:16:07 GMT FROM: Javier Gorosabel at LAEFF-INTA, Madrid J. P. U. Fynbo (ESO, Garching), J. Gorosabel (DSRI, Copenhagen), B. L. Jensen, H. Pedersen, J. Hjorth (U. of Copenhagen), M. I. Andersen (University of Oulu), A. A. Kaas, T. Abbott, T. H. Dall and R. Oestensen (NOT), report "Using the ALFOSC on the 2.5m Nordic Optical Telescope, we have obtained R-band imaging of the optical counterpart of GRB 010222 (GCN #961, GCN #963). We have derived the following preliminary magnitudes; Date, Feb 2001(UT) R Texp(s) ========================================= 23.008--23.012 19.56+-0.03 300 23.015--23.019 19.53+-0.03 300 23.020--23.023 19.56+-0.03 300 23.083--23.086 19.65+-0.03 300 23.087--23.091 19.68+-0.03 300 23.145--23.148 19.76+-0.03 300 23.165--23.167 19.79+-0.05 100 Our zero-point is based on the the reference star 'A' of McDowell et al. (GCN #963). We have fitted a power-law light curve to the magnitudes reported by Stanek et al. (GCN #970) and to the ones displayed above. We obtain a value for the slope of 0.86+-0.01 (chi^2/dof= 12.7/8=1.6), which is consistent with the one reported by Price et al. (GCN #973)" //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 976 SUBJECT: GRB 010222: Optical Observations DATE: 01/02/23 07:18:51 GMT FROM: Jerome A. Orosz at Astro. Inst, Utrecht U. Jerome A. Orosz, Utrecht University, The Netherlands, reports: I have observed the field of GRB010222 (GCN 959,960) with the 1 meter Jacobus Kapteyn Telescope on La Palma. The conditions were nearly photometric (very thin cirrus moved in at the last minute) and the seeing was 1.2 arcseconds. The preliminary magnitudes given are with respect to star 'A' in Stanek et al.'s finding chart (GCN 970): UT start Filter exptime airmass delta_mag on Feb 23 06:16:28.0 R 600.0 1.037762 2.95 +/- 0.06 06:27:43.0 V 600.0 1.043099 2.83 +/- 0.07 06:38:45.0 I 600.0 1.050021 2.66 +/- 0.13 06:49:46.0 R 600.0 1.058645 2.82 +/- 0.15 Thus assuming star A has R=17, then the OT had R = 19.95 +/- 0.06 on UT 23.2614. I have observed several Landolt fields that can be used to approximately calibrate the field after the fact. These images and the GRB images are available upon request. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 977 SUBJECT: GRB 010222: Near-IR Observations DATE: 01/02/23 10:50:16 GMT FROM: Angelo Antonelli at Obs. Astro. di Roma A. Di Paola, L.A. Antonelli, G. Li Causi, Osservatorio Astronomico di Roma, Italy, G. Valentini, Osservatorio Astronomico di Teramo, Italy, on behalf of a larger collaboration report: "We observed the Optical Transient candidate of GRB 010222 reported by Handen, GCN #961 and McDowell et al., GCN #963 in J and K band with the AZT-24 1.1-meter telescope at Campo Imperatore (AQ). The J-band observation started at February 23.0078 UT and the field was imaged for a total exposure time of 2200 sec. A point-like source was observed in a position consistent with the OT position (GCN #961, #963). The source was detected with a S/N=10 and had a magnitude of J=18.7+/-0.1. Another J-band observation started at February 23.1674 and the field was imaged for a total exposure time of 2200 sec. The source was still detected at a S/N=5 and had a magnitude of J=19.3+/-0.2 The K-band observation started at Feb. 23.0681 UT and the field was imaged for a total exposure time of 2700 sec. The source was detected with a S/N=8 and had a magnitude of K=17.4+/-0.3. The J-band images are posted at http://argos.mporzio.astro.it/angelo/grb010222/ This message is citable." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 980 SUBJECT: GRB010222 R-BAND OBSERVATION DATE: 01/02/23 15:43:47 GMT FROM: Mauro Dolci at Teramo Obs. (OACT), Italy F. Massi, M. Dolci, E. Di Carlo, Osservatorio Astronomico di Teramo, Italy, report: We carried out R-band observations of the GRB010222 field at the 0.72 m telescope of the Osservatorio Astronomico di Teramo, starting on Feb 23.083 UT and ending on Feb 23.156 UT, with a total integration time of 75 min. Preliminary data reduction shows a faint object at the location indicated by Stanek et al. (GCN 970). Using their star "A" as a comparison star, we found R=19.20 p/m 0.06 on our coadded unflattened image. Further reduction is under way. This message can be cited. [GCN OPS NOTE(23Feb01): This Circular was receive 23 Feb 01 05:50 UT but was delayed due to an improper account name.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 982 SUBJECT: GRB 010222 BV optical observations DATE: 01/02/23 22:13:54 GMT FROM: Corrado Bartolini at Universita di Bologna C. Bartolini, A. Guarnieri, A. Piccioni (Dip. Astronomia, Univ. of Bologna), S. Bernabei (Astron. Obs., Bologna) and G. Pupillo (ISAO, CNR, Bologna) report: "We have imaged the proposed optical counterpart (GCN #961) of GRB010222 (GCN #959, 960) on February 23 in the B and V bands with the 152 cm Loiano telescope (plus EEV CCD) of the Observatory of Bologna. The seeing was 4 arcseconds. The preliminary magnitudes are given with respect to the comparison star "A" (GCN 963) = USNO 1275-08542334. mean UT Filter exptime delta_mag (s) 23.174 B 2400 2.04 +/- 0.07 23.199 V 1800 2.69 +/- 0.09 Thus assuming for the star "A" B=17.60, then the OT had B = 19.64 +/- 0.07". //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 983 SUBJECT: GRB010222: fading behavior DATE: 01/02/24 03:39:15 GMT FROM: Krzysztof Z. Stanek at CfA K. Z. Stanek, P. Challis, S. Jha, R. Kilgard, J. McDowell (Harvard-Smithsonian CfA) and P. M. Garnavich (Notre Dame) report: We have obtained additional R-band data for the optical afterglow of the GRB010222 using the F. L. Whipple Observatory 1.2m telescope: HJD-2450000 UT R_c exp 1963.9457 010223 10:48 20.16+-0.07 600 sec Combined with our earlier R-band data (GCN 970), this indicates a power-law decay with a slope of 0.89, consistent with previous determinations (GCNs 973, 975). In the B-band, between 4.3 hours and 24.2 hours after the burst the afterglow dimmed by about 1.8 magnitudes: HJD-2450000 UT B exp 1962.9855 010222 11:46 18.46+-0.02 600 sec 1963.8173 010223 07:43 20.25+-0.10 600 sec This is consistent with no color evolution between B and R. Errors in the magnitudes are statistical only. The B-band magnitudes are relative to star "A" as marked in the finding chart at http://cfa-www.harvard.edu/cfa/oir/Research/GRB/, assuming its magnitude B=17.6. Reductions of additional data are under way. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 984 SUBJECT: GRB 010222 Kyoto optical observation DATE: 01/02/24 10:20:09 GMT FROM: Taichi Kato at Kyoto U GRB 010222 Kyoto optical observation M. Uemura, R. Ishioka, H. Iwamatsu, T. Kato, Kyoto Univ., and H. Yamaoka, Kyushu Univ., on behalf of VSNET-GRB collaboration report: We observed the field of GRB 010222 starting at Feb. 22, 12:16 UT, with 0.30-m Schmidt-Cassegren telescope (+ unfiltered CCD) at Kyoto University. The GRB was detected on the images. The following photometry has been obtained: mid UT total exp. delta mag detection level Feb. 22.534 (22.511-22.554) 2160s 3.09 (1.7 sigma) 22.852 (22.842-22.861) 1350s 4.61 (6.2 sigma) The magnitudes are relative to PG 1450+432 (V=14.50). By assuming Rc = 14.70 for this star (Henden et al.), the observed magnitudes are 17.8 and 19.3 respectively. The low detection level of the first run was a result of low-alititude haze. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 985 SUBJECT: GRB010222, possible increase of optical decay slope DATE: 01/02/24 18:59:09 GMT FROM: Nicola Masetti at ITeSRE,CNR,Bologna N. Masetti, E. Palazzi (ITeSRE, CNR, Bologna), E. Pian (Oss. Astron. Trieste), A. Zacchei, A. Magazzu, M. Pedani, F. Ghinassi (TNG) and M. Mignoli (Oss. Astron. Bologna), on behalf of a larger collaboration, report: "We observed the optical transient (Henden, GCNs #961, #962) associated with GRB010222 (Piro, GCNs #959, #960) in the R band with TNG+Dolores on 2001 Feb. 24.236 UT (i.e. ~2 days after the GRB). The total exposure time was 4 minutes; seeing was 0.9 arcsec. Using star `A' by Stanek et al. (GCN #970) as reference, we note that our measurement, R = 20.88 +- 0.03, is ~0.4 mag fainter than the extrapolation of the t^{-0.9} decay measured by Price et al. (GCN #973), Fynbo et al. (GCN #975) and Stanek et al. (GCN #983). The power-law decay between our TNG measurement and that made in the R filter by Stanek et al. (GCN #983) on Feb. 23.45 has an index ~1.3. Thus, our data seem to suggest that a break occurred at ~1 day after the GRB in the R-band light curve of the afterglow. Further observations are strongly encouraged to confirm (or reject) this result.". This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 986 SUBJECT: GRB010222 further R-band photometry DATE: 01/02/24 19:09:07 GMT FROM: Mauro Dolci at Teramo Obs. (OACT), Italy G. Valentini, F. Massi, M. Dolci and E. Di Carlo, Osservatorio Astronomico di Teramo (Italy), report: New R-band observations of the GRB010222 field have been carried out with the 512 x 512 CCD camera (4' x 4' FOV) at the focus of the 0.72-m telescope of the Osservatorio Astronomico di Teramo. A more accurate photometric calibration has been performed both on these new data and on the ones previously reported by us (GCN 980). The photometric stability during both nights was roughly 0.06 mag. Final results for the observations reported on Feb 23 (GCN 980) indicate R=19.63 p/m 0.05 with respect to the R=17 star "A" from Stanek et al. (GCN 970). However, a calibration made using SA106-1024 from the Landolt catalogue yields R=16.7 for star "A" and R=19.33 for the GRB counterpart candidate (seeing 3.6 arcsec). No colour correction was applied. The latest set of images was acquired starting on Feb 24.085 UT and ending on Feb 24.174 UT, for a total exposure time of 2 hours. The source was no longer detected above a 3-sigma limiting magnitude R=21 (seeing about 5 arcsec). This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 987 SUBJECT: GRB010222, field photometry DATE: 01/02/25 00:44:50 GMT FROM: Arne A. Henden at USNO/USRA A. Henden (USRA/USNO) reports on behalf of the USNO GRB team: We have acquired preliminary UBVRcIc all-sky photometry for the field of GRB010222 with the USNOFS 1.0-m telescope on one photometric night with poor seeing. This 11x11arcmin field includes the proposed counterpart and extends to approximately V=20. All stars brighter than V=14 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/grb010222.dat The current photometry has a potential external zero-point error of about two percent that needs to be added in quadrature to the Poisson errors given in the datafile and also below. The astrometry in this file is based on linear plate solutions with respect to USNO-A2.0. The internal errors are less than 100mas. In particular, the values for the two comparison stars noted in the literature are: ID U B V Rc Ic Henden A GCN967 13.311 14.318 14.570 14.688 14.829 0.002 0.002 0.002 0.002 0.004 Stanek A GCN970 18.680 18.349 17.613 17.175 16.761 0.045 0.014 0.010 0.015 0.017 Note that Henden star A has nearly identical R-magnitude to the value listed in USNO-A2.0, whereas observations made with respect to Stanek star A will have to be adjusted fainter. At least two additional nights of photometry will be added to the data file when weather conditions permit. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 989 SUBJECT: GRB 010222: Keck Spectroscopy DATE: 01/02/25 06:52:49 GMT FROM: Josh Bloom at CIT GRB 010222: Keck Spectroscopy J. S. Bloom, S. G. Djorgovski (Caltech), J. P. Halpern (Columbia), S. R. Kulkarni, T. J. Galama, P. A. Price, S. M. Castro (Caltech) report on behalf of the larger Caltech-NRAO-CARA GRB Collaboration: "We obtained two epochs of optical spectroscopy of the transient of GRB 010222 (GCN #959; #961) using the dual-CCD Low-Resolution Imaging Spectrometer (LRIS; Oke et al. 1995) on the Keck I 10-m telescope on Mauna Kea, Hawaii. We confirm the redshifts of the two absorption systems previously reported by Garnavich et al. (GCN #965) and Jha et al. (GCN #974). We find an additional absorption system at z=0.928 as well other as yet unidentified absorption lines. The first set of spectra were taken by R. -P. Kudritzki and F. Bresolin on 22.66 Feb 2001 UT using the 300/5000 grism (blue side) and 400/8500 grating (red side) with a total integration time of 1800s on-source in both CCDs. The second set of spectra were taken by H. Spinrad, D. Stern, A. Dey, A. Bunker, and S. Dawson on 23.66 Feb 2001 UT with the identical setup and integration time as the first epoch. A preliminary comparison of absorption-line strengths reveals no significant variation of the equivalent widths between the two epochs." We thank A. A. Henden for providing an image of the GRB field which facilitated the first epoch of spectroscopy. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 990 SUBJECT: GRB010222 Optical observations DATE: 01/02/25 20:14:35 GMT FROM: Arto Oksanen at Nyrola Obs., Finland A. Oksanen, M. Moilanen, H. Hyvonen, R. Pasanen, and P. Tikkanen of the Nyrola Observatory GRB team and the AAVSO International GRB network, report: We observed the optical transient for GRB010222 (GCN 961) with the 0.4m telescope and ST7E CCD camera of the Nyrola Observatory on the night of 010222/010223 UT. Observing conditions were quite good: sky was clear, but strong wind enlarged the star images. Our preliminary untransformed BVR measures of the OT (GCN 961) from that night, using Henden star A (GCN 967) as calibrated by Henden (GCN 987) for the comparison star, are as follows: UT (mid) mag merr filter exposure(s) ---------------------------------------------- 20010222.8227 19.84 0.31 B 12x300 20010222.8744 19.57 0.13 Rc 12x300 20010222.9187 19.70 0.13 V 12x300 20010222.9661 19.69 0.15 Rc 12x300 20010223.0134 19.92 0.14 V 12x300 20010223.0628 19.92 0.17 Rc 12x300 20010223.1439 20.29 0.21 V 6x300 20010223.1665 20.11 0.31 Rc 6x300 The images are available on http://nyrola.jklsirius.fi/grb/grb010222/. We want to thank A. Henden (USRA/USNO) about preparing this circular. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 991 SUBJECT: GRB010222: R-band data DATE: 01/02/26 00:30:59 GMT FROM: Krzysztof Z. Stanek at CfA K. Z. Stanek and E. Falco (Harvard-Smithsonian CfA) report: We have obtained additional R-band data for the optical afterglow of the GRB010222 using the F. L. Whipple Observatory 1.2m telescope: UT R_c exp 25.4385 21.48+-0.08 2x600 sec Fitting a simple power-law decay to our data taken about one day after the burst (GCN 983) and the current data yields a slope of about 1.3. This confirms the steepening decay of the optical afterglow, as indicated by Masetti et al. (GCN 985). Fitting broken power-law to all the data produces a food fit, but the parameters of the fit are at present underconstrained, except that the break seems to be gradual, beta<<1. Continuing imaging is needed, also in the BVI-bands if possible. The R-band magnitude is relative to star "A" as marked in the finding chart at http://cfa-www.harvard.edu/cfa/oir/Research/GRB/, assuming its magnitude R=17.0. Because of the discrepancy between the values assigned to "A" by Valentini et al. (GCN 986: R=16.7) and Henden (GCN 987: R=17.175), we decided for now to continue using R=17.0 as our fiducial point. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 992 SUBJECT: GRB010222 further R-band photometry DATE: 01/02/26 13:48:51 GMT FROM: Mauro Dolci at Teramo Obs. (OACT), Italy Remark: Correction to the magnitude of star "A" and GRB counterpart candidate in GCN 986 G. Valentini, F. Massi, M. Dolci and E. Di Carlo, Osservatorio Astronomico di Teramo (Italy), report: New R-band observations of the GRB010222 field have been carried out with the 512 x 512 CCD camera (4' x 4' FOV) at the focus of the 0.72-m telescope of the Osservatorio Astronomico di Teramo. A more accurate photometric calibration has been performed both on these new data and on the ones previously reported by us (GCN 980). The photometric stability during both nights was roughly 0.06 mag. Final results for the observations reported on Feb 23 (GCN 980) indicate R=19.63 p/m 0.05 with respect to the R=17 star "A" from Stanek et al. (GCN 970). However, a calibration made using SA106-1024 from the Landolt catalogue yields R=17.42 p/m 0.01 for star "A" and R=20.05 p/m 0.05 for the GRB counterpart candidate (seeing 3.6 arcsec). No colour correction was applied. The latest set of images was acquired starting on Feb 24.085 UT and ending on Feb 24.174 UT, for a total exposure time of 2 hours. The source was no longer detected above a 3-sigma limiting magnitude R=21 (seeing about 5 arcsec). This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 993 SUBJECT: GRB 010222 DATE: 01/02/26 20:36:28 GMT FROM: Tetsuharu Fuse at Subaru Telescope, NAOJ During our Edgeworth-Kuiper belt object survey using Subaru telescope at Mauna Kea, we observed optical counterpart of the GRB 010222 detected by BeppoSAX using accurate coordinate reported by the Naval Observatory. Roughly estimated R-band magnitude was 18.9 +/- 0.1 at 22.642 (UT) using following stars PG1528+062A, SA104 338, and SA104 339. Due to the lack of standard star around 22.508 (UT), we conducted relative photometry and obtained 18.4 +/- 0.1 at 22.508 (UT). This preliminary result suggests the shallow slope for the lightcurve of GRB 010222. We would like to express our hearty thanks to URATA Yuji at the Science University of Tokyo for helping us to estimate appropriate exposure time. WATANABE, Jun-ichi National Astronomical Observatory of Japan KINOSHITA, Daisuke Graduate University for Advanced Studies FUSE, Tetsuharu National Astronomical Observatory of Japan KOMIYAMA, Yutaka National Astronomical Observatory of Japan FUJIHARA, Gary National Astronomical Observatory of Japan POTTER, Bob National Astronomical Observatory of Japan HARASAWA, Sumiko National Astronomical Observatory of Japan This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 994 SUBJECT: GRB 010222 HST/Chandra TOO DATE: 01/02/27 00:17:33 GMT FROM: Shri Kulkarni at Caltech Dear Colleagues: This note is to inform you that, under the aegis of our HST AO-9 program, we have requested observations of GRB 010222 (GCN 959) with the Hubble Space Telescope and the Chandra X-ray Observatory. This burst with a bright optical (GCN 962, 963) and radio (GCN 968) afterglow appears to be particularly well suited for detailed studies of the afterglow and the circumburst medium. The Hubble observations involves six visits: STIS/NUV-MAMA (Feb 26), WFPC2 (Feb 28, March 9, March 15-19, TBD, TBD). In addition, a 30-ksec ACIS Chandra observation is expected to be conducted on March 6. We encourage parallel ground based observations of this burst so that it will become a very well studied afterglow. We will be supplementing the HST and Chandra observations with detailed multiwavelength observations at facilities to which our group has access (e.g. Keck, Palomar, MDM, HET). In the radio, we are undertaking observations with the VLA, JCMT, IRAM, Ryle, OVRO and Nobeyama. Shri Kulkarni, Titus Galama and Fiona Harrison on behalf of a large international GRB collaboration. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 995 SUBJECT: GRB 010222 DATE: 01/02/27 12:56:58 GMT FROM: Michael Bremer at IRAM Grenoble Interferometric Millimeter Observations of GRB 010222 M. Bremer (1), A. Castro-Tirado (2,3) and R. Moreno(1) report: (1) IRAM (Grenoble, France) (2) IAA-CSIC (Granada, Spain) (3) LAEFF-INTA (Madrid, Spain) We have observed the GRB 010222 radio counterpart with the Plateau de Bure Interferometer (PdBI) in a compact five antenna configuration on February 24.94 - 25.11 UT, using the position from Henden et al. (GCN 967). Weather conditions were good for wavelengths of 3mm but marginal for 1mm. The flux calibration was relative to CRL 618 (1.55 Jy at 3mm and 2 Jy at 1mm) and is accurate to about 10%. The source was not detected. UV fits on the phase center give the following upper limits (fit errors are one sigma) : 93.109 GHz : -0.49 +- 0.32 mJy/beam 232.032 GHz : -0.09 +- 1.6 mJy/beam The results have been corrected for atmospheric decorrelation. Synthesized beams were 9.3" x 5.2" at PA -57 degrees and 3.6" by 2.3" at PA -46 degrees, respectively. No bright sources were detected within the primary beam. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 996 SUBJECT: Sub-millimeter Excess/GRB 010222 DATE: 01/02/27 13:28:18 GMT FROM: Shri Kulkarni at Caltech S. R. Kulkarni (Caltech), D. A. Frail (NRAO), G. Moriarty-Schieven (JAC), F. Bertoldi (MPIfR), F. Walter (OVRO), D. Shepherd (NRAO), R. Sari (Caltech), D. E. Reichart (Caltech) and S. G. Djorgovski (Caltech) report: Observations of the afterglow of GRB 010222 have continued with the SCUBA sub-millimeter continuum bolometer array on the James Clark Millimetre Telescope (JCMT). The first observation, reported in GCN#971 by Fich et al. was begun 5.6 hrs after the burst on Feb 22 at 13:03 UT. Two additional observations were made beginning on Feb 23.46 UT and Feb. 24.68 UT, or 27.7 hrs and 56.8 hrs after the burst. The source had a 350 GHz flux density of 4.2+/-1.2 mJy, 3.6+/-0.9 mJy and 4.2+/-1.3 mJy on these three days, respectively. In contrast to the bright sub-millimeter emission, the source is weak or undetectable at millimeter wavelengths. F. Bertoldi has conducted observations with the Max-Planck Millimeter Bolometer (MAMBO) array (220 GHz) on the IRAM 30-m telescope on the nights of February 23 and the 24. The data reduction is in progress. However, the preliminary results are 1.4+/-0.5 mJy and 1.2+/-0.3 mJy, respectively. F. Walter and D. Shepherd have conducted observations at the OVRO Interferometer (98 GHz). The observations of Feb 23.81 yield an upper limit of -0.3 +/-0.8 mJy. [At the time of the submission we recieved GCN 995 which reports similar upper limits from PdBI but for the epoch Feb 24.94-25.11 UT]. The relative constancy of the 350 GHz flux density and the steep spectrum between 220 GHz and 350 GHz (spectral slope>+2.4) cannot be reconciled with standard afterglow models. Free-free or synchrotron self-absorption in the millimeter band is unlikely because the source is detectable at centimeter wavelengths (GCN#968). Thus we conclude that the sub-millimeter flux originates as a distinct emission component, separate from the main afterglow emission (which dominates the centimeter fluxes). The simplest hypothesis is that the the sub-millimeter flux arises from the host galaxy. Indeed, the sub-millimeter flux of the host (assumed to be at redshift of 1.467; GCN 965, GCN 989) is typical of star-forming galaxies selected in SCUBA surveys. The star formation rate estimated in the usual manner (Carilli & Yun, ApJ, L13, 1999) is 500 Msun/yr -- typical of the sample of dusty, high redshift starburst galaxies (Smail et al. 2000; astro-ph/000823). This inference is entirely consistent with models in which GRBs are related to massive stars. There is considerable diversity in the morphology and star-formation rates of star-forming galaxies and this also appears to be the case for GRB selected host galaxies. If the relation between GRBs and starformation holds strictly then GRBs, thanks to the immense dust penetrating power of gamma-rays, could be used to select a sample of star-formation galaxies with no bias towards dust. The additional advantage of this sample is that the afterglow offers the opportunity to measure the redshift of the host galaxy (as is the case here). There are other possible explanations for the sub-millimetric excess such as reprocessing of the burst (flash) by the ambient dust or a very strong reverse shock. We are investigating these possibilities but they appear to be less likely or contrived. In the host hypothesis, we expect the sub-millimeter emission to be constant and we also expect a contribution (about 100 microJy) at 1.4 GHz (from synchrotron emission). Continued observations at radio wavelengths are urgently required both to test the constancy of the sub-millimeter flux and also to monitor the afterglow emission. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 998 SUBJECT: GRB010222: Optical observation and decay DATE: 01/03/01 09:21:10 GMT FROM: Christian Veillet at CFHT The optical counterpart of GRB010222 has been observed using the CFHT Multi Object Spectrograph in imaging mode at the Cassegrain focus of the 3.6-m CFH Telescope on the night of Feb. 27 to 28. One image was obtained in relatively poor conditions (seeing ~ 1.5"). A preliminary reduction using stars (223.008250,43.006507) and (223.098277,42.994077) from Henden's list (GCN #987) gives: Feb. 28.653 UTC R = 22.60 +/- 0.15 The relative photometry of the two stars used is consistent with our image within 0.02 magnitudes. Using all the measurements of the R magnitude of the OT published in the GCN's (corrected if needed to put them back in the photometric system of Henden's list), the R magnitude is following a nice power law decay with an index of 1.20 +/- 0.07 since 0.6 days after the burst. An image of the OT and a graph of the decay are available at http://www.cfht.hawaii.edu/~veillet/grb.html S. Lilly and J. McDonald are acknowledged for their help in this observation. This message may be cited. -- ************************************************************ Dr. Christian Veillet, CFHT Senior Resident Astronomer Phone: (808) 885-3161 http://www.cfht.hawaii.edu/~veillet/ ************************************************************ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 999 SUBJECT: GRB 010222: High-Resolution Keck Spectroscopy DATE: 01/03/01 18:08:06 GMT FROM: George Djorgovski at Caltech/Palomar GRB 010222: High-Resolution Keck Spectroscopy S. Castro, S. G. Djorgovski, S. R. Kulkarni, J. S. Bloom, T. J. Galama, D. E. Reichart, P. A. Price (Caltech), H. Ebeling (IfA Hawaii), and D. A. Frail (NRAO), report on behalf of the Caltech-NRAO-CARA GRB collaboration: Spectra of the optical transient associated with GRB 010222 (GCN # 959, 961) have been obtained on 23.61 February UT by H. Ebeling, using the Echelle Spectrograph and Imager (ESI) on the Keck-II 10-m telescope. Preliminary analysis shows the following: We confirm the existence of 3 absorption systems reported earlier (GCN # 965, 974, 989), with improved heliocentric redshifts as follows: (1) z_abs = 1.4768 +- 0.0002 (based on 22 metallic lines) This system, presumably associated with the host galaxy, appears to have some kinematic substructure, possibly with two distinct systems at z_1 = 1.47667 +- 0.00005 and z_2 = 1.47755 +- 0.00005, i.e., with a restframe velocity separation of 106 km/s, typical for internal motions in galaxies. The equivalent widths of the lines are unusually strong in comparison to metallic line absorbers seen in the spectra of quasars, indicating a high column density of gas, probably consistent with a star-forming region environment. (2) z_abs = 1.1561 +- 0.0001 (based on 9 metallic lines) (3) z_abs = 0.9274 +- 0.0001 (based on 5 metallic lines) Systems (2) and (3) are typical for the metallic line absorbers at comparable redshifts. Detection of two such foreground systems is not unusual. Further analysis of the data is in progress. This note can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1000 SUBJECT: GRB010222 - Optical observation DATE: 01/03/02 02:16:03 GMT FROM: Christian Veillet at CFHT The optical counterpart of GRB010222 has been observed using the CFHT Multi Object Spectrograph in imaging mode at the Cassegrain focus of the 3.6-m CFH Telescope on the night of Feb. 28 to March 1. Two 10 mn images were obtained in much better conditions than the night before (GCN #998) with a seeing of about 0.8". There are only a few point like sources in the vicinity of the OT. A star like object ~11" S of the OT has been carefully measured with respect to the two stars used in GCN #998 and has a very consistent R magnitude on the MOS exposures (R = 20.13 +/- 0.02). A fainter object 8" from the OT is used for internal consistency checks at R = 22.35. Precise reduction of the images from Feb. 28 and March 1 gives the following results: Feb. 28.653 UTC R = 22.73 +/- 0.10 Mar. 01.628 UTC R = 22.96 +/- 0.10 The index of the power law decay given in GCN #998 is not significantly modified and found as 1.25 +/- 0.06. There is not structure found on the OT, which is still seen as a point source on the March 1 combined image. More information (with the new images of the OT) can be found at http://www.cfht.hawaii.edu/~veillet/grb.html M. Pakull, L. Mirioni, and J. McDonald are acknowledged for their help in this observation. This message may be cited. -- ************************************************************ Dr. Christian Veillet, CFHT Senior Resident Astronomer Phone: (808) 885-3161 http://www.cfht.hawaii.edu/~veillet/ ************************************************************ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1002 SUBJECT: GRB 010222, Optical Observations DATE: 01/03/02 21:19:06 GMT FROM: Stephen Holland at U. of Notre Dame An Early Break in the Optical Light Curve of GRB 010222 Stephen Holland (Notre Dame) Johan Fynbo (ESO) Javier Gorosabel (DSRI) Arne Henden (USNO) Jens Hjorth (Copenhagen) Brian Jensen (Copenhagen) Holger Pedersen (Copenhagen) We have obtained deep Cousins R-band images of the optical afterglow associated with GRB 010222 using the 2.5m Nordic Optical Telescope (NOT) at La Palma and the USNO 1.0m telescope at Flagstaff Station. Preliminary magnitudes, using Rc = 17.175 for Stanek's (2001a, GCN 970) Star "A", as calibrated by Henden (2001, GCN 987), are: UT(middle) Rc err Telescope ----------------------------------------------- 2001:02:23.0102 19.733 0.014 NOT 2001:02:23.0171 19.707 0.013 NOT 2001:02:23.0216 19.739 0.012 NOT 2001:02:23.0844 19.829 0.011 NOT 2001:02:23.0889 19.852 0.010 NOT 2001:02:23.1463 19.933 0.009 NOT 2001:02:23.1661 19.960 0.014 NOT 2001:02:23.2116 20.031 0.009 NOT 2001:02:23.2858 20.126 0.018 NOT 2001:02:24.0701 20.950 0.024 NOT 2001:02:24.1313 20.975 0.024 NOT 2001:02:24.1358 21.012 0.025 NOT 2001:02:24.1410 21.052 0.025 NOT 2001:02:24.1579 21.006 0.023 NOT 2001:02:24.1750 21.043 0.025 NOT 2001:02:24.1863 21.000 0.023 NOT 2001:02:24.2469 21.035 0.022 NOT 2001:02:25.0534 21.536 0.057 NOT 2001:02:25.0579 21.426 0.058 NOT 2001:02:25.2535 21.638 0.044 NOT 2001:02:25.2583 21.667 0.041 NOT 2001:02:22.4874 18.39 0.05 USNO 2001:02:22.5241 18.51 0.05 USNO 2001:02:22.5236 18.67 0.06 USNO 2001:02:22.5385 18.66 0.06 USNO 2001:02:24.4632 21.23 0.06 USNO ----------------------------------------------- In order to maintain as much uniformity as possible in the photometry we first restrict ourselves to data taken with the NOT. This data extends from 0.70 to 2.95 days after the burst and is consistent with a single power law with a slope of -1.24 +/- 0.02 (Q < 99.954%). We supplemented this data with R-band photometry of GRB 010222 from Stanek et al. (2001a, GCN 970), Price et al. (2001, GCN 973), Orosz (2001, GCN 976), Stanek et al. (2001b, GCN 983), Masetti et al. (2001, GCN 985), Oksanen et al. (2001, GCN 990), Stanek & Falco (2001, GCN 991), Velentini et al. (2001, GCN 992), Watanabe et al. (2001, GCN 993), and Veillet (2001, GCN 1000). All the photometry was adjusted to the photometric zero points of Henden (2001a, GCN 987), except for that of Veillet (2001, GCN 1000), which was used "as is". The photometry was corrected for Galactic extinction assuming a reddening of E(B-V) = 0.023 and an R-band extinction of A_R = 0.061. The complete data set is not consistent with a single power law (Q < 0.001%). Photometry earlier than 0.33 days after the burst is weakly consistent with a single power law with a slope of -0.71 +/- 0.13 (Q = 77.969%), and the photometry later than 0.57 days after the burst is consistent with a single power law with a slope of -1.24 +/- 0.02 (Q = 99.990%). Fitting a broken power law (see Holland et al., 2000, A&A, 364, 467 for the method) to the light curve yields a break at 0.48 +/- 0.11 days (11.5 +/- 2.6 hours) after the burst, and slopes of -0.72 +/- 0.13 before the break and -1.24 +/- 0.02 after the break (Q = 99.991%). The smooth function of Beuermann et al. (1999, A&A, 352, L26) with slopes of -0.67 +/- 0.34 before the break, -1.29 +/- 0.06 after the break, and an exponent of 1.8 +/- 4.4 provides a slightly better fit (Q = 99.998%) to the data than the broken power law does. Our fits suggest that the break occurred rapidly between 0.33 and 0.57 days (8 and 14 hours) after the burst. A plot of the light curve and the two fits, along with a deep composite image of the field containing the GRB, is available at "http://www.nd.edu/~sholland/grb/grb010222/index.html". This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1003 SUBJECT: GRB010222 - Optical observation DATE: 01/03/03 00:39:04 GMT FROM: Christian Veillet at CFHT The optical counterpart of GRB010222 has been observed using the CFHT Multi Object Spectrograph in imaging mode at the Cassegrain focus of the 3.6-m CFH Telescope on the night of March 1 to 2. Two 10 mn images were obtained with a seeing of about 0.8". Photometric reduction made as outlined on GCN #1000 leads to: Mar. 2.641 R = 23.10 +/- 0.10 The index of the power law decay fitting the R light curve data since 0.6 days after the burst (including the revised and new measurements by Holland et al. in GCN #1002) is 1.25 +/- 0.03, the same as our previous determination (Veillet, GCN #1000) and not significantly different from the GCN #1002 value. While a few objects are now seen in a radius of 4", the OT is still a point like object. More information (with the new images of the OT) can be found at http://www.cfht.hawaii.edu/~veillet/grb.html M. Pakull, L. Mirioni, and J. McDonald are acknowledged for their help in this observation. This message may be cited. -- ************************************************************ Dr. Christian Veillet, CFHT Senior Resident Astronomer Phone: (808) 885-3161 http://www.cfht.hawaii.edu/~veillet/ ************************************************************ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1004 SUBJECT: GRB010222: Sub-millimeter vanishing act DATE: 01/03/03 05:32:43 GMT FROM: Ian Smith at Rice U R.J. Ivison, C.E. Jenner (University College London), W.E. Lundin, R.P.J. Tilanus (JAC), and I.A. Smith (Rice University) report: Further observations of GRB 010222 made using the SCUBA sub-millimeter continuum bolometer array on the James Clerk Maxwell Telescope now fail to significantly detect the counterpart described in GCN #971 and #996. The observations, made between 14:54 and 18:05 on 2001 March 2 UT, give a preliminary 850 micron flux density of 0.7 +/- 1.1 mJy. A 1-hour observation on the previous night is consistent with this result. It thus appears as if the source detected earlier is not the quiescent host galaxy. Indeed, of the 17 bursts studied with SCUBA to date, that have measured redshifts between 0.707 and 3.4, no conclusive detections of quiescent sub-millimeter hosts have so far been found (Smith et al. 1999, A&A, 347, 92; Smith et al. 2001, A&A, in press). At least at 850 microns, GRB 010222 may be similar to GRB 980329, which also had an apparent excess in the SCUBA observations and whose sub-millimeter flux decayed rapidly with time (unfortunately, the first SCUBA observations were not made until 7 days after that burst). A final SCUBA observation of GRB 010222 is planned during the coming week. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1005 SUBJECT: GRB010222: Chandra X-ray Observatory Observation DATE: 01/03/04 18:19:25 GMT FROM: Gordon Garmire at Penn State U GRB 010222: Chandra Observation of the afterglow G. P. Garmire, A. B. Garmire (Penn State), L. Piro(IAS/CNR Frascati), E. Schlegel(Harvard-Smithsonian CfA) A Chandra observation of GRB010222 (GCN 959, 960) with ACIS-S started on Feb. 22 22:28 UT, i.e. 15 hours after the burst, and lasted for 30 ksec. The X-ray afterglow of the burst was detected at a position RA(2000)= 14h52m12.51s, Decl(2000)=+43 01'06.2" (with an error of 1"), consistent with the position of the OT (GCN963). The source was very bright, and a more detailed analysis is under way to take into account pile-up effects. Gordon Garmire ACIS IPI [GCN OPS NOTE(04Mar01): This message was received on 01Mar01 21:00 UT, but was delayed due it not being sent directly to the Circular processing demon and because the GCN operator was on travel until 04 Mar.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1007 SUBJECT: GRB 010222 - HEGRA GeV/TeV Observations DATE: 01/03/09 12:59:27 GMT FROM: Spanish HEGRA group at XXXX GeV/TeV Observations of GRB 010222 N. Goetting (1) and D. Horns (2) on behalf of the HEGRA Collaboration report: (1) University of Hamburg (Germany) (2) Max-Planck-Institut f. Kernphysik, Heidelberg (Germany) On February 23rd beginning at UT 02:37 the BeppoSAX position of GRB 010222 (GCN 960) was observed by the stereoscopic HEGRA Cherenkov telescope system on La Palma (approx. 19 hours after the outburst). The object was observed for 4 hours at altitudes > 45 degrees under good weather conditions. The source was not detected above a threshold photon energy of 760 GeV. A preliminary data analysis gives an upper limit on the photon flux at the 90% confidence level: J(E > 760 GeV) < 9.4 * 10^(-12) erg cm^(-2) s^(-1) Contemporaneous observations of the Crab nebula were used to derive this upper limit. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1009 SUBJECT: GRB010222, late-time optical observation DATE: 01/03/20 20:15:03 GMT FROM: Peter Garnavich at Center for Astrophysics P. Garnavich, J. Quinn (Notre Dame) and K. Z. Stanek (CfA) The field of GRB 010222 was imaged with the 1.8m Vatican Advanced Technology Telescope (VATT) on 2001 March 18 and 19 (UT). The total exposure time in R band was 3 hours in average seeing of 1.2". A faint source is detected within 0.2" of the position of the optical afterglow (GCN 961, 962). Using PSF fitting photometry we find R=24.53+/-0.25 mag assuming the Henden calibration of the nearby stars (GCN 987). The estimated magnitude is consistent with the extrapolated light curve assuming a power-law with index -1.33 (after the break at 0.7 days). A number of galaxies are visible within 10" of the afterglow. The brightest is a compact galaxy with R=22 mag, 4.2" (PA=10 deg) from the GRB. Three faint galaxies, all 4" from the afterglow have PA=280, 230, and 200 deg with respect to the afterglow. The VATT image is available at "http://cfa-www.harvard.edu/cfa/oir/Research/GRB/". //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1023 SUBJECT: GRB010222, CXO X-ray observations DATE: 01/03/26 20:19:23 GMT FROM: Fiona Harrison at CalTech F. A. Harrison, S. A. Yost, S. R. Kulkarni report on behalf of a larger collaboration: We observed the field containing GRB010222 with Chandra ACIS for 17 ksec, beginning on March 3.44 UT. We detect an X-ray source within 1" of the position of the optical transient (GCN 961, 962) 14:52:12.55 43:01:06.26 (J2000) and consistent with the X-ray transient detected by the BeppoSAX NFI (GCN 966). Preliminary analysis shows a 2-10 keV X-ray flux of 7.2e-14 erg/cm2/s for this source. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1051 SUBJECT: GRB 010222 /corrections to VBT data DATE: 01/04/27 09:23:31 GMT FROM: SG Bhargavi at Indian Inst of Astrophysics R Cowsik and SG Bhargavi (IIA Bangalore, India) report: Results of observations of afterglow of GRB 010222 obtained from 2.34-m VBT are as follows: Feb 24.977 600s I 20.8 +- 0.2 ** Feb 24.9924 600s R 21.405 +/- 0.17 Feb 25.9816 900s I 21.42 +/-0.18 Feb 25.9955 900s R 21.99 +/-0.13 Feb 28.9014 1200s R >22.1 Feb 28.9257 2400s R >22.1 Mar 1.9319 1800s R >21.9 ** It may be noted that some of these are the final numbers and those quoted in Table.1 in astroph/0104363 (Cowsik et al.) were priliminary. Further details on measurements on these data may be obtained from Bhargavi (2001; Ph D thesis). We acknowledge S Ambika and K Jayakumar for observations. This messge may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1082 SUBJECT: GRB 010222 - WHT BVRI images DATE: 01/07/11 09:02:10 GMT FROM: Isabel Salamanca at U. of Amsterdam Isabel Salamanca, Paul Vreeswijk, Evert Rol, Lex Kaper (Anton Pannekoek Institute, University of Amsterdam), Nial Tanvir (University of Hertfordshire), Andy Fruchter (STScI), Ralph Wijers (SUNY, Stony Brook), Chryssa Kouveliotou (NASA/MSFC), Thomas Augusteijn and Almudena Zurita (La Palma) report: On May 22, 2001, we have obtained B,V,R,I images of the field of GRB 010222 (Piro et al. GCN 959) with the Prime Focus Camera at the 4.2-m William Herschel Telescope (La Palma, Spain). The aim of these observations was to detect the host galaxy. The observations were done in photometric conditions, with seeing 1.1 arcsec. The details of the observation are as follows: Filter Exposure Star 'A' Limiting mag (sec) (Stanek, GCN 970) (3 sigma, aperture=1xFWHM) ----------------------------------------------------- B 900 18.38 25.4 V 675 17.62 25.8 R 675 17.13 24.4 I 675 16.76 24.3 Photometry was done by using 7 standard stars in the field SA110 of the Landolt Catalog (AJ, 1992, vol 104, pag 340). The resulting magnitudes of star 'A' are in excellent agreement (between 0.01 and 0.04 mag) with the values reported by Henden et al. (GCN 987). No host galaxy (or any other object) is detected at the position of the optical afterglow of GRB010222 (RA = 14:52:12.55, DEC =+43:01:06.2, J2000). Very close to the position of the GRB010222, we detect two objects, most probably galaxies. The very faint galaxies reported by Garnavich et al (GCN 1009) are not visible in our images, although there is a hint of one of them. The photometry and positions of these two galaxies are as follows: Galaxy 1 RA = 14:52:12.4, DEC = +43:00:58.7, J2000 1.6 arcsec W, 7.6 arcsec S ---------------------------------------------------- B = 23.51 +/- 0.10 V = 23.16 +/- 0.11 R = 22.47 +/- 0.08 I = 20.77 +/- 0.12 Galaxy 2: RA = 14:52:12.7, DEC = +43:01:09.9, J2000 1.6 arcsec E, 3.6 arcsec N ------------------------------------------------------ B = 24.45 +/- 0.24 V = 23.79 +/- 0.18 R = 23.05 +/- 0.15 I > 24.3 (affected by fringing) The error in the coordinates is about 0.24 arcsec. The error in the magnitudes is the formal error obtained with the task 'phot' of Iraf. A figure can be seen at http://zon.wins.uva.nl/~evert/grb010222/ This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1087 SUBJECT: GRB 010222: HST observations -- host galaxy and late-time decay DATE: 01/08/14 18:45:00 GMT FROM: Andrew S. Fruchter at STScI A. Fruchter, I. Burud, J. Rhoads and A. Levan (STScI) report: We have reduced the now public archival HST images of GRB 010222, taken on 28 February, 17 and 18 March, 5 and 6 April, and 4 and 5 May of this year using the F606W (V/R) and F814W (I) filters on WFPC2. Using the most recent data, we find that OT of GRB 010222 is clearly superposed on a host galaxy. In order to accurately determine the decay of the OT and the magnitude of the host, we have drizzled the images onto an output grid that allows interlacing of these 2-point dithered images. We have then fit for the decay of the OT and the host galaxy flux using a small (~0."2) aperture, which provides the best estimate of the OT as a function of time, as well as using a larger aperture (~0."5), which is more appropriate for determining the host galaxy magnitude. We find that the late-time decay of the OT is significantly steeper than previously reported. We find a power-law decay between 28 February (day 6) and 5 May (day 71) of -1.7 +/- 0.05. Formally, we find a slightly steeper decay (-1.73 +/- 0.02) in F606W than in F814W (-1.64 +/- 0.04), but this discrepancy may indicate the level of systematic error in the slope measurement rather than true color evolution of the OT. We find that the host galaxy is dominated by a compact core (FWHM ~ 0."15) located directly under the OT. The magnitude of the host is F606W(AB) = 26.0 +/- 0.1, F814W(AB) = 25.8 +/- 0.15. Images of the host, as well as a plot of the coninuing decline of the OT, are available at http://www.stsci.edu/~fruchter/GRB/010222