//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8865 SUBJECT: GRB 090201: Swift detection of a burst DATE: 09/02/01 17:54:29 GMT FROM: David Palmer at LANL S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Schady (MSSL-UCL) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 17:47:02 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090201 (trigger=341749). Swift could not immediately slew due to the Earth limb constraint. The BAT on-board calculated location is RA, Dec 92.031, -46.586 which is RA(J2000) = 06h 08m 07s Dec(J2000) = -46d 35' 10" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multiple-peaked structure with a duration of about 110 sec. The peak count rate was ~10000 counts/sec (15-350 keV), at ~7 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+45.3 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8866 SUBJECT: GRB 090201: ROTSE-III Optical Limits DATE: 09/02/01 19:01:36 GMT FROM: Brad Schaefer at LSU B. E. Schaefer (Louisiana State) reports on behalf of the ROTSE collaboration: ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 090201 (Swift trigger 341749; S. R. Oates et al., GCN 8865), producing images beginning 41 minutes after the burst trigger. Weather constraints in Namibia were the cause of the delay, as we had to await the clearing of the skies. Our first image was at 18:28:03.6 UT, 2460.9 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and -8 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going. Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle, for both single images and coadding into sets of 10; the field is not crowded. Swift has not slewed to this burst yet, so there is no XRT position to examine in detail. Individual images have limiting magnitudes ranging from 16.6-17.4; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 18:28:03.6 18:29:03.6 60 16.6 2460.9 N 18:28:03.6 18:30:15.5 131 16.9 2460.9 Y 18:42:25.4 18:54:11.1 705 18.2 3322.7 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8868 SUBJECT: GRB 090201: Swift-XRT detection of the possible X-ray afterglow DATE: 09/02/01 19:35:30 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore and K.L. Page (U. Leicester) report on behalf of the Swift-XRT team : The Swift-XRT started observing the field of GRB 090201 (Oates et al, GCN Circ. 8865) in photon counting mode at 18:50:40.7UT, 63.6 minutes after the trigger. In 1.4 ks of promptly downlinked data we detect a source at a position of RA, Dec = 92.0530, -46.5888, which is RA (J2000) = 06h 08m 12.74s Dec (J2000) = -46d 35m 19.8s with an uncertainty of 3.5 arcsec (radius, 90% containment). The source is 55.5 arcsec from the reported BAT position and within its error circle. We do not have sufficient data at this stage to tell if the source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8869 SUBJECT: GRB 090201: VLT afterglow candidate DATE: 09/02/02 01:54:09 GMT FROM: Paolo D'Avanzo at INAF-OAB "P. D'Avanzo, C. C. Thoene, D. Fugazza (INAF-OAB), V. D'Elia (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We observed the field of GRB 090201 (Oates et a., GCN 8865) with the ESO-VLT in imaging mode starting about 7.5 hours after the burst. Observations were carried out in R and I-band with the FORS2 camera. At the edge of the XRT error circle (Beardmore et al. GCN 8868) we find a very faint source at the following coordinates (J2000): R.A. = 06:08:12.92 Dec. = -46:35:17.3 +/- 0.3" Preliminary photometry of this candidate afterglow gives R ~ 25.2 and I ~ 24.1. Further observations are ongoing. We acknowledge the VLT staff for their support, in particular E. Valenti and J. Smoker. [GCN OPS NOTE(02jan09): Per author's request, RS was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8870 SUBJECT: GRB 090201: Swift-BAT refined analysis DATE: 09/02/02 04:13:21 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+363 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090201 (trigger #341749) (Oates, et al., GCN Circ. 8865). The BAT ground-calculated position is RA, Dec = 92.051, -46.604 deg, which is RA(J2000) = 06h 08m 12.3s Dec(J2000) = -46d 36' 16.1" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 8%. The mask-weighted light curve shows two clusters of overlapping peaks. The first starting at ~T-20 sec and peaking at ~T+8 sec. The second peaks at ~T+39 sec and ends at ~T+120 sec. T90 (15-350 keV) is 83 +- 4 sec (estimated error including systematics). The time-averaged spectrum from T-10.2 to T+102.2 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.88 +- 0.18, and Epeak of 104 +- 16 keV (chi squared 39.5 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.0 +- 0.1 x 10^-5 erg/cm2 and the 1-sec peak flux measured from T+7.60 sec in the 15-150 keV band is 14.7 +- 1.0 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.50 +- 0.04 (chi squared 76.3 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/341749/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8871 SUBJECT: GRB 090201: VLT NIR observations DATE: 09/02/02 04:51:55 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, C. C. Thoene, D. Fugazza (INAF-OAB), V. D'Elia, S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We continued observing the field of GRB 090201 (Oates et a., GCN 8865) with the ESO-VLT in imaging mode with the ISAAC NIR camera. Observations were carried out in J, H and K-band about 9.5 hours after the burst. The optical afterglow candidate (D'Avanzo et al. GCN 8869) is not visible in the coadded images down to the following upper limits (3sigma c.l.): J = 23.0, H = 22.4, K = 21.1 (calibrated against the 2MASS catalogue). The absence of a NIR detection suggests that the object observed by D'Avanzo et al. (GCN 8869) is not the optical afterglow of GRB 090201 but probably a field galaxy. Further analysis is in progress. We acknowledge the VLT staff for their support, in particular E. Valenti and J. Smoker. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8872 SUBJECT: GRB 090201: Enhanced Swift-XRT position DATE: 09/02/02 04:52:21 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 3196 s of XRT Photon Counting mode data and 8 UVOT images for GRB 090201, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 92.05202, -46.59045 which is equivalent to: RA (J2000): 06h 08m 12.48s Dec (J2000): -46d 35' 25.6" with an uncertainty of 1.4 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8873 SUBJECT: GRB 090201: object inside the enhanced XRT error circle DATE: 09/02/02 05:29:17 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, C. C. Thoene, D. Fugazza (INAF-OAB), V. D'Elia, S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: Following the enhanced XRT position (Beardmore et al. GCN 8872) we re-analyzed our VLT optical and NIR images of the field of GRB 090201 (D'Avanzo et al. GCNs 8869, 8871). We find an object at the following coordinates (J2000): R.A. = 06:08:12.48 Dec. = -46:35:24.2 +/- 0.5" consistent with the enhanced XRT position. Preliminary photometry of this object gives R ~ 24.6 and J ~ 21.8. The moderate red color suggests that this object likely is the afterglow of GRB 090201. Further observations are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8874 SUBJECT: GRB090201: Swift UVOT upper limits DATE: 09/02/02 11:05:00 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL-UCL) and S. Oates (MSSL-UCL) report on behalf of the Swift UVOT team The Swift/UVOT began settled observations of the field of GRB 090201 3668s after the BAT trigger (Oates et al., GCN 8865). We do not detect any source at the enhanced Swift XRT position (Beardmore et al. GCN 8872) or at the VLT optical and NIR afterglow candidate (D'Avanzo et al. GCN 8873) down to the following 3-sigma upper limits: Filter T_start(s) T_stop(s) Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- White 3668 5051 344 > 21.53 v 3825 10589 1159 > 20.63 b 4646 16906 834 > 21.38 u 4440 16245 1082 > 21.15 uvw1 4235 14730 448 > 20.16 uvm2 4030 11123 717 > 20.53 uvw2 5056 5256 197 > 20.03 The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.07 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8875 SUBJECT: GRB 090201: Swift-XRT refined analysis DATE: 09/02/02 11:12:04 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore, K.L. Page (U. Leicester), S.R. Oates (UCL-MSSL) report on behalf of the Swift-XRT team. The Swift-XRT started observing the BAT GRB 090201 (trigger #341749, Oates et al., GCN circ. 8865) at 18:47:33 UT, 3.65ks after the trigger. The UVOT-enhanced X-ray position has been reported in Beardmore et al. (GCN Circ. 8872). Using 14.5ks of photon counting mode data taken from T+3.65ks to T+39.2ks after the trigger, we find the X-ray light curve can be described by a broken powerlaw, with initial decay slope of 0.64 +0.17 -0.15, break time of 7.2 +2.1 -1.5 ks and final decay slope of 1.45 +/- 0.11. The spectrum spanning the same interval can be fit by an absorbed powerlaw, with a photon index of 2.20 +/- 0.10 and column density of 4.78 +/- 0.42 x 10^21 cm^-2, compared with the Galactic column of 4.9 x 10^20 cm^-2 in the direction of the burst. The observed (unabsorbed) 0.3-10 keV flux is (1.00 +/- 0.06) x 10^-11 [(2.02+/-0.12) x 10^-11] erg cm^-2 s^-1. Assuming the decay continues at the same rate, we predict a count rate of 0.017 count/s 1 day after the trigger, which corresponds to an observed 0.3-10 keV flux of 7.4e-13 erg cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8878 SUBJECT: Konus-Wind observation of GRB 090201 DATE: 09/02/03 12:27:16 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 090201 (Swift-BAT trigger #341749: Oates et al., GCN 8865; Baumgartner et al., GCN 8870) triggered Konus-Wind at T0=64020.275 s UT (17:47:00.275). The burst light curve shows a multipeaked structure with a duration of ~110 s. As observed by Konus-Wind the burst had a fluence of 6.72(-0.54, +0.47)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+11.728 s of 7.30(-1.28, +1.24)x10^-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+107.520 s) is well fitted (in the 20 keV - 2 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.97(-0.09, +0.10), the high energy photon index beta = -2.80(-0.92, +0.29), the peak energy Ep = 158(-12, +13) keV (chi2 = 51.0/59 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB090201_T64020/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8955 SUBJECT: Radio observation of GRB 090201 with ATCA DATE: 09/03/09 06:56:08 GMT FROM: Aquib Moin at CIRA/ATNF Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope National Facility), Steven Tingay (Curtin Institute of Radio Astronomy), Chris Phillips (Australia Telescope National Facility), Gregory Taylor (University of New Mexico), Mark Wieringa (Australia Telescope National Facility) and Ralph Martin (Perth Observatory) report: We observed the VLT position of the GRB090201 optical afterglow (GCN 8873) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array (ATCA) between 01:00:00 UT and 22:00:00 UT on February 21/22, 2009. We did not detect a radio source at the optical afterglow position of the GRB090201 (GCN 8873). The data at 4.800 and 4.928 GHz were merged and the radio flux density at the afterglow position found out to be -0.430 +/- 0.280 mJy/beam (1-sigma). The Australia Telescope Compact Array (/ Parkes telescope / Mopra telescope / Long Baseline Array) is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. See the 4.800 & 4.928 GHz combined image at: http://cira.ivec.org/dokuwiki/doku.php/grb/grb090201/grb090201_field_image