TITLE: GCN/RXTE_ASM BURST POSITION NOTICE NOTICE_DATE: Fri 26 Jan 01 16:02:03 UT NOTICE_TYPE: RXTE-ASM Initial TRIGGER_NUM: No correlation with BATSE is possible. GRB_DATE: 11935 TJD; 26 DOY; 01/01/26 GRB_TIME: 33040.37 SOD {09:10:40.37} UT POSITION_TYPE: Line GRB_RXTE_RA: 178.795d {+11h 55m 11s} (J2000), 178.809d {+11h 55m 14s} (current), 178.146d {+11h 52m 35s} (1950) GRB_RXTE_DEC: +49.253d {+49d 15' 11"} (J2000), +49.247d {+49d 14' 49"} (current), +49.531d {+49d 31' 53"} (1950) GRB_RXTE_ERROR: 0.800 [deg half-length (stat+sys),90%] GRB_RXTE_LINE_LENGTH: 1.500 [deg] GRB_RXTE_LINE_WIDTH: 0.059 [deg] GRB_RXTE_LINE_POS_ANGLE: -147.010 [deg] GRB_RXTE_INTEN: 1100.00 [mCrab] SUN_POSTN: 308.88d {+20h 35m 30s} -18.65d {-18d 39' 02"} SUN_DIST: 129.82 [deg] MOON_POSTN: 329.78d {+21h 59m 06s} -15.98d {-15d 58' 55"} MOON_DIST: 139.23 [deg] COMMENTS: RXTE-ASM GRB Coordinates. COMMENTS: This GRB was only seen in one camera. COMMENTS: This was a singly-peaked burst in the ASM, COMMENTS: lasting about 20-s. It was very hard, with COMMENTS: fluxes of 1.8, 2.5 and 5.0 Crab in the 1.5-3, COMMENTS: 3-5, and 5-12 keV bands, respectively. We COMMENTS: await confirmation from high-energy instruments COMMENTS: that this is a GRB. [GCN OPS NOTE (26/01/01): The GRB_DATE was corrected to be 01/01/26 (from 01/01/25).] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 921 SUBJECT: IPN/RXTE TRIANGULATION OF GRB010126 DATE: 01/01/26 21:07:32 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team, and D. Smith, on behalf of the RXTE ASM GRB team, report: This burst, which was incorrectly reported as occurring on the 25th in today's GCN notice, was observed, with rather poor statistics, by Ulysses. It had a duration of ~10 s, a 25-100 keV fluence of ~2 x 10^-6 erg/cm^2, and a peak flux over 0.25 s of ~7 x 10^-7 erg/cm^2 s. These numbers should be regarded as very approximate due to the weakness of the burst. We have done a very rough, preliminary triangulation using the RXTE ASM 5 - 12 keV data and the Ulysses 25 - 150 keV data. Although the time histories are somewhat different in these two energy ranges, the result indicates that the GRB came from the northern part of the RXTE ASM error box, above declination ~ 49 o 20 '. If this event was observed by Konus-WIND or NEAR, a smaller error box can probably be derived. [GCN OPS NOTE: Please note that the calendar dates for the recent GCN/RXTE_ASM_GRB_POSITION Notice contained an error. The date was listed as GRB_DATE: 11935 TJD; 25 DOY; 01/01/25 but the correct dates are GRB_DATE: 11935 TJD; 26 DOY; 01/01/26 This error occurred in the GCN processing of the ASM message -- it was not part of the original ASM submission. The burst occurred today, and not yesterday as might be inferred by casual inspection of the DOY or YY/MM/DD fields. GCN apologizes for this error.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 922 SUBJECT: IPN TRIANGULATION OF GRB010126 DATE: 01/01/26 22:47:10 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team, T. Cline, E. Mazets, and S. Golenetskii, on behalf of the Konus-WIND GRB team, and D. Smith, on behalf of the RXTE ASM GRB team, report: Ulysses and Konus observed this burst at ~33048 s. Triangulation gives a Ulysses/KONUS/RXTE error box whose area is ~50 sq. arcmin. and whose coordinates are: RA(2000) DEC(2000) ERROR BOX CENTER: 11 h 57 m 08.61 s 49 o 44 ' 36.00 " ERROR BOX CORNER 1: 11 h 56 m 19.62 s 49 o 34 ' 54.86 " ERROR BOX CORNER 2: 11 h 56 m 52.98 s 49 o 38 ' 27.86 " ERROR BOX CORNER 3: 11 h 57 m 48.00 s 49 o 51 ' 48.00 " ERROR BOX CORNER 4: 11 h 57 m 34.00 s 49 o 53 ' 13.00 " If NEAR observed this burst, it may be possible to refine this error box further. The RXTE data may be found at http://xte.mit.edu/grb010126/ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 923 SUBJECT: GRB010126: Optical observations DATE: 01/01/27 05:30:09 GMT FROM: Paul Price at RSAA, ANU at CIT P.A. Price (Caltech), A. Gal-Yam (Wise Obs.) and J.S. Bloom (Caltech) report on behalf of a larger collaboration: "We have observed the IPN error box of GRB010126 (Hurley et al. GCN #922) with the Wise 40-inch telescope in R-band starting at approx Jan 27.04 UT. Our 8x600s images cover the entire error box with two overlapping pointings. The effective integration time varies over the area of the error box. From visual inspection of the combined image, we do not find any objects which are not present on the Digital Sky Survey 2 red plate." [GCN OPS NOTE (27jan01): A typo on the observation time was corrected from 21.04 UT to 27.04 UT.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 924 SUBJECT: GRB010126 optical observations DATE: 01/01/28 17:30:27 GMT FROM: Adalberto Piccioni at Astronomy, Bologna U. GRB010126 C. Bartolini, A. Guarnieri and A. Piccioni, Departement of Astronomy, Bologna University, and S. Bernabei, L. Fabbroni and R. Gualandi, Bologna Observatory, communicate: "We observed the error box of GRB010126 on January 27, 2001, in poor weather conditions (seeing 2".5) with the 1.5 m Loiano telescope. Two CCD frames, 13'X13', centered on the error box center reported by K. Hurley on GCN922, were obtained in R band with start times UT 01:05:00 (30 min) and UT 01:39:00 (20 min), respectively. A preliminary inspection of the two frames shows a possible variable object (r.a. 11 57 07.3, de. 49 44 26.5) not present in the DSSII-red, barely over the plate detection limit. This object, by comparison between the two frames, seems to be fading. Deeper analysis is in progress." [GCN OPS NOTE(28 Jan 01): This Circular was sent at 01/01/27 04:29:01 GMT, but was not distributed because the submitor was not in the vetted list at that time.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 925 SUBJECT: GRB010126 Optical Observations DATE: 01/01/29 13:14:56 GMT FROM: Holger Pedersen at Copenhagen U Obs H. Pedersen, J. Hjorth, B. L. Jensen (U. of Copenhagen), M. I. Andersen (University of Oulu), J. P. U. Fynbo (ESO, Garching), J. Gorosabel (DSRI, Copenhagen), A. A. Kaas (Nordic Optical Telescope), L. Takalo, and R. Rekola (Tuorla Observatory), report on behalf of a wider collaboration: GRB010126 Optical Observations ------------------------------ "Using the 2.56-m Nordic Optical Telescope (+ALFOSC), La Palma, we have obtained a total of eight images which cover the error box (Hurley, GCN 922) by means of four consecutive pointings: UT Filter Exp.time Seeing =========================================================== 2001 January 27.21 R (4 x ) 180 s 0.85" FWHM 2001 January 28.13 R (4 x ) 180 s 0.90" FWHM Intercomparison of the images has revealed no candidate counterpart to magnitude ~22.5 . The object reported by Bartolini et al. (GCN 924) is detected on two overlapping exposures, i.e. 360 s, at each epoch. Using the nearby USNO star U1350_08031605 as reference, we find R = 21.17 +/- 0.20 (epoch 1) and R = 21.29 +/- 0.20 (epoch 2), i.e. consistent with no variability." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 926 SUBJECT: GRB010126, TNG R-band observations DATE: 01/01/29 16:53:29 GMT FROM: Nicola Masetti at ITeSRE,CNR,Bologna N. Masetti, E. Palazzi (ITeSRE, CNR, Bologna), M. Pedani, A. Magazzu, F. Ghinassi (TNG) and E. Pian (OATs, Trieste), on behalf of a larger collaboration, report: "We acquired optical R-band images of the central part of the GRB010126 Ulysses/Konus/RXTE error box (Hurley et al., GCN #922) on 2001 Jan. 27.26 and 28.27 UT (i.e. 21 and 45 hours after the GRB) with TNG+Dolores. The total exposure time was 10 minutes for each epoch. Seeing was 1.3 and 1.7 arcsec on the two epochs, respectively. The images covered about 60% of the GRB error box. Photometric calibration was performed using the USNO-A2.0 catalog star U1350_08031829, with magnitude R = 17.9 and coordinates (J2000) RA = 11 57 10.29; Dec = +49 46 58.9. The comparison between the two epochs does not reveal any object with significant brightness variation down to a 3-sigma limiting magnitude R ~ 23.5 . The object reported by Bartolini et al. (GCN #924) is well detected on both epochs and is constant within the measurement errors at magnitude R = 21.29 +- 0.05 (excluding zero-point calibration uncertainties). This is consistent with the findings by Pedersen et al. (GCN #925).". This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 927 SUBJECT: GRB010126: CONCAM crude optical limits during GRB DATE: 01/01/30 00:16:18 GMT FROM: Robert Nemiroff at Michigan Tech. R. J. Nemiroff, D. Perez-Ramirez, W. E. Pereira, J. B. Rafert, C. Ftaclas, and J. Fernandez (Michigan Tech) report on behalf of the CONCAM collaboration: The CONtinuous CAMera (CONCAM) operating at Kitt Peak National Observatory has recorded fisheye images that provide crude limits on the attributes of an OT through non-detection. A relevant CONCAM frame contains an integration from 33022 s to 33202 s that brackets 33048 s, the time of the GRB trigger reported by Hurley et al. in GCN922, and the duration of the GRB as reported by Hurley et al. in GCN 921. Raw FITS data are available at http://concam.net . Processed GIF images of this frames, the previous frame, and the following frame, are available here: http://concam.net/kp010126/kp010126ut0902.gif http://concam.net/kp010126/kp010126ut0910.gif http://concam.net/kp010126/kp010126ut0914.gif No obvious optical counterpart down to about visual magnitude 6.3 over the three-minute exposure is visible on the frames. This is, to the best of our knowledge, the first time an optical electronic instrument was observing a GRB location during a GRB trigger. The time recorded on the CONCAM frames are behind the actual UT time by about 26 seconds. We have corrected for this in this report so that the uncertainty in the above reported times is only about 2 seconds. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 928 SUBJECT: IPN/RXTE TRIANGULATION OF GRB010126 DATE: 01/01/31 18:34:52 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team, D. Smith, on behalf of the RXTE-ASM GRB team, T. Cline, on behalf of the Konus-Wind and NEAR GRB teams, and E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, report: NEAR observed this event, previously reported in GCN 921 and 922. Triangulating this burst with Ulysses, Konus, and NEAR gives a preliminary, 3 sigma error box whose area is ~240 sq. arcmin. and whose coordinates are: RA(2000) DEC(2000) 11 h 58 m 45.64 s 50 o 2 ' 41.37 " (CENTER) 12 h 0 m 2.95 s 49 o 59 ' 3.02 " (CORNER) 12 h 1 m 3.73 s 50 o 5 ' 46.18 " (CORNER) 11 h 56 m 25.01 s 49 o 59 ' 30.17 " (CORNER) 11 h 57 m 27.75 s 50 o 6 ' 17.68 " (CORNER) Although this error box is consistent with the previous triangulations, it excludes the 90% confidence RXTE-ASM error box, and therefore the IPN/RXTE error boxes which were based on it. However, extending the long dimension of the ASM error box from 1.5 degrees (90% confidence) to 2.0 degrees (3 sigma) does produce an RXTE-ASM/IPN intersection. The resulting error box has an area of ~20 sq. arcmin. whose coordinates are: RA(2000) DEC(2000) 11 h 58 m 21.49 s 50 o 02 ' 20.00 " (CENTER) 11 h 57 m 59.42 s 49 o 59 ' 20.44 " (CORNER) 11 h 58 m 18.57 s 49 o 59 ' 18.09 " (CORNER) 11 h 58 m 40.70 s 50 o 04 ' 38.00 " (CORNER) 11 h 58 m 27.26 s 50 o 06 ' 04.00 " (CORNER) A map has been posted at ssl.berkeley.edu/ipn3/010126 showing the new RXTE-ASM error box and its intersection with the IPN annuli. (Do not attempt to derive coordinates from this map, which is a plane projection.) We regret any confusion caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 929 SUBJECT: GRB010126 opt. obs. DATE: 01/02/01 11:17:50 GMT FROM: Adalberto Piccioni at Astronomy, Bologna U. GRB010126 C. Bartolini, A. Guarnieri, A. Piccioni , Departement of Astronomy, and S. Bernabei, Bologna Observatory communicate: "Photometry of the object pointed out by us in GCN 924: start time Jan 27.0451; R = 21.3 +- 0.2 ; exp. time 30 min start time Jan 27.0687; R = 21.3 +- 0.4 ; exp. time 20 min Calibration star: USNO U350_08031605. The hypotized short term variability (GCN 924) is excluded. Although these values are well above the detection limit of DSSII-red, the object is not present on it. This behaviour is consistent with a long term, large amplitude variable or an eclipsing binary. Our two CCD images can be retrieved by secure shell ftp at the address: GRB@ermione.bo.astro.it, username GRB, passwd 01_0126."