//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6986 SUBJECT: GRB 071025: Swift detection of a burst DATE: 07/10/25 04:30:05 GMT FROM: Claudio Pagani at PSU/Swift-XRT C. Pagani (PSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), J. L. Racusin (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team: At 04:08:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071025 (trigger=295301). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 355.084, +31.757 which is RA(J2000) = 23h 40m 20s Dec(J2000) = +31d 45' 24" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Although this is a 64 sec image trigger, the light curve appears to have a single broad peak with duration about 120 sec near time T+100, with peak count rate 2000 ct/s. The XRT began observing the field at 04:11:19 UT, 146 seconds after the BAT trigger. XRT found a bright, fading, uncatalogued X-ray source located at RA, Dec 355.0765, +31.7776 which is RA(J2000) = 23h 40m 18.3s Dec(J2000) = 31d 46' 39.3" with an uncertainty of 6.8 arcseconds (radius, 90% containment). This location is 78 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 0.1s image was 9.1e-09 erg/cm2/s (0.2-10 keV). UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 155 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.08. Burst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu). 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: 6987 SUBJECT: GRB 071025: ROTSE-III Detection of Optical Counterpart DATE: 07/10/25 04:37:51 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986). The first image was at 04:10:14.0 UT, 80.3 s after the burst (6.0 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 19.2 magnitude, fading source with coordinates: 23:40:17.19 +31:46:42.64 (J2000), with positional uncertainty of 1" or better start UT mag mlim(of image) ---------------------------------- 04:16:27.1 19.2 18.6 This source is not visible in DSS (second epoch), 2MASS or the MPChecker database. A jpeg image is available at http://www.rotse.net/images/gsb295301_3b021-030_key.jpg Continuing observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6988 SUBJECT: GRB071025: REM NIR afterglow DATE: 07/10/25 04:48:54 GMT FROM: Stefano Covino at Brera Astronomical Observatory S. Covino, S. Piranomonte, D. Fugazza, L.A. Antonelli, L. Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, P. D'Avanzo, V. D'Elia, F. Dalessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team: The NIR afterglow is detected by the REM telescope at coordinates: RA = 23:40:17.1 DEC = 31:46:43.6 with H~13.8 at 4:18:12 UT. The source is NOT in the XRT error circle, although rather close to it. The source is bright, and not present in the 2MASS or USNO catalogues. The source is compatible with that reported by Rykoff et al. (GCN 6987). Further observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6989 SUBJECT: GRB 071025a: PAIRITEL observations DATE: 07/10/25 05:07:57 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom (UC Berkeley) reports on behalf of a larger collaboration: "Under autonomous operations, we started observing the position of GRB 071025a (Pagani et al. GCN 6986) with PAIRITEL at 04:11:08 UT (about 58s after receiving the trigger). In a mosaic of data obtained between 2007-10-25 04:12:28 to 2007-10-25 04:21:23 UT, we confirm the existence of a bright new source (Rykoff et al. GCN 6987; Covino et al. GCN 6988) at position: 23:40:17.078 +31:46:42.87 (J2000) with an uncertainty of 250 mas in both axes (relative to 2MASS). A preliminary magnitude is J = 14.948 +/- 0.022. More observations and analysis are ongoing." A finder of the field may be obtained at: http://lyra.berkeley.edu/~jbloom/grb071025a.ps.gz The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6990 SUBJECT: GRB 071025: Swift XRT refined position DATE: 07/10/25 05:19:35 GMT FROM: Claudio Pagani at PSU/Swift-XRT C. Pagani (PSU) reports on behalf of the Swift-XRT Team: The XRT on-board centroid position of the afterglow of GRB 071025 reported in GCN 6986 was strongly affected by a hot column. A refined position from the first 0.1 second image is RA, Dec=355.0737, 31.7782 which is RA(J2000) =23h 40m 17.7s Dec(J2000) =+31d 46' 41.4" with an uncertainty of 8 arcseconds (radius, 90% containment). This is 9 arcseconds from the initial XRT position, and 6.5 arcseconds from the optical position reported in GCN 6897. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6991 SUBJECT: GRB 071025: I-detection, R-dropout? DATE: 07/10/25 05:43:23 GMT FROM: Myungshin Im at Seoul Nat U M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team: Using the Mt. Lemmon (Arizona, US) 1.0m telescope operated by the Korea Astronomy Space Science Institute, we observed GRB071025, beginning at 04:35 UT on Oct 25. We have a clear detection of the afterglow in 300 secs frame taken in I-band (GCN6987, Rykoff et al.), but no detection at all in B, V, R-band with the same exposure time. The non-detection R-band suggests that the GRB is likely a R-band dropout at z ~ 6. This message may be cited. We acknowldege the help of the LOAO operators, J.H. Yoon, for this observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6992 SUBJECT: GRB 071025: ROTSE-III Refined Analysis DATE: 07/10/25 06:54:28 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986, Pagani, et al.) and detected an optical counterpart as reported in GCN 6987 (Rykoff, et al.). We have improved the photometry and recalibrated the images relative to USNO-B1.0 R-band, which is significantly offset from the magnitudes in USNO-A2.0 R-band. From our initial observations at T+80.3s we see the counterpart rise to a peak of 17.3+/-0.2 at T+332s (midtime for a 40s coadd), and then fade slowly over the next 1500 s. At T+595s (midtime for a 280s coadd) the magnitude is 17.6+/-0.1. This integration is nearly simultaneous with the NIR detections of H~13.8 (Covino, et al., GCN 6988) and J=14.95 (Bloom, et al., GCN 6989). Although the ROTSE-III images are calibrated relative to R-band, the unfiltered CCD has significant sensitivity redward of R. Our observations are thus consistent with a possible R-band dropout (Im, et al., GCN 6991) and UVOT non-detection (Pangani, et al., GCN 6986). We can assume that the intrinsic GRB spectrum as an R-J color of ~1, and the reddening is entirely caused by the intergalactic medium (IGM). We then use the ROTSE-III magnitude and the integrated ROTSE-III response curve convolved with the IGM absorption model of Meiksin (2005) to estimate an upper limit on the burst redshift of z~5.3 (for more details see Ruiz-Velasco, et al, 2007). We note that at this redshift the R-band offset would be ~1.2 mag, which may be consistent with the limits of Im, et al. However, if the reddening is not caused by absorption in the IGM then the burst redshift may be lower. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6994 SUBJECT: GRB 071025: R/I-band update DATE: 07/10/25 07:56:36 GMT FROM: Myungshin Im at Seoul Nat U M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team: We coninue examination of the data obtained with the Mt. Lemmon (Arizona, US) 1.0m telescope. The afterglow appears to be decaying rapidly after ~2400 secs of the burst. Re-examination of R-band images show a faint smudge which could be due to the afterglow. The detection is consistent with GCN report 071025 (Rykoff et al.), and we set the limit of R -I > ~1.7 mag from our R-band observation. Note that our R-band filter has a long tail toward red wavelenth. Below are rough estimates of I-band magnitudes based on USNO-B stars (error ~ 0.15mag). Star time (UT) Exp Time I mag -------------------------------------- 04:38:08 300s 16.8 05:08:42 300s 17.2 05:30:48 300s 18.1 Further examination of the BVRI data is ongoing to check whether this is a red GRB or high-z GRB. This message may be cited. We acknowldege the help of the LOAO operators, J.H. Yoon, for this observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6995 SUBJECT: GRB 071025: Early Super-LOTIS Observations DATE: 07/10/25 09:54:28 GMT FROM: Grant Williams at Steward Observatory G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of the Super-LOTIS Collaboration, report: The robotic 0.6-m Super-LOTIS telescope began observing the error box of GRB 071025 (Swift Trigger 295301, Pagani et al. GCN 6986) at 04:10:29.3 UT, 95 seconds after the trigger. Our initial observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band. We detect the afterglow reported by Rykoff et al. (GCN 6987, confirmed by Covino et al. GCN 6988) in the sum of our first ten 60s exposures centered on 04:19:39 UT. We do not detect the afterglow in our single 10s or 20s exposures. Using USNO-B1.0 stars we estimate the following R-band magnitude and upper limits for the OT: t_start (UT) t_mid (UT) exp t (s) t_start-t_0 (s) R Mag ----------------------------------------------------------------------------------------------------- 04:10:29.3 04:10:34.3 10 95.3 R > 17.3 04:13:42.1 04:13:52.1 20 288.1 R > 17.8 04:14:08.8 04:19:39.0 600 314.8 R = 17.97 +/- 0.17 Our upper limit of R > 17.8 was measured near the time of the unfiltered m=17.3 peak reported by Rykoff et al. (GCN 6992). Additional observations and analysis are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6996 SUBJECT: GRB 071025, Swift-BAT refined analysis DATE: 07/10/25 11:29:48 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), C. Pagani (PSU), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+422 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071025 (trigger #295301) (Pagani, et al., GCN Circ. 6986). The BAT ground-calculated position is RA, Dec = 355.065, 31.784 deg, which is RA(J2000) = 23h 40m 15.6s Dec(J2000) = 31d 47' 3" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 48%. The mask-weighted light curve shows a broad peak composed of several overlapping subpeaks. It starts at ~T+0 sec, peaks around T+90 sec, and slowly decays out to at least T+422 sec. Because of an observing constraint, the s/c had to slew off the burst location, and so we do not have any information on the continuation of the emission beyond the T+422 sec limit. T90 (15-350 keV) is at least 109 +- 2 sec (estimated error including systematics). The time-averaged spectrum from T+38.5 to T+193.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.79 +- 0.05. The fluence in the 15-150 keV band is 6.5 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+80.17 sec in the 15-150 keV band is 1.6 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6998 SUBJECT: GRB 071025: Swift-XRT Team refined analysis DATE: 07/10/25 14:14:05 GMT FROM: Claudio Pagani at PSU/Swift-XRT C. Pagani, D. N. Burrows, J. Racusin (PSU), P. Evans (U Leicester) report on behalf of the Swift-XRT Team: We have analysed the first three orbits of Swift-XRT data obtained for GRB 071025 (Pagani et al. GCN Circ. 6986), totalling 250 s of Windowed Timing (WT) data and 2.7 ks of Photon Counting (PC) data. Using 1189 seconds of overlapping XRT Photon Counting mode and UVOT V-band data, 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 = 355.07142, 31.77857 which is equivalent to: RA (J2000): 23 40 17.14 Dec (J2000): +31 46 42.9 with an uncertainty of 1.7 arcsec (radius, 90% confidence). This is 7.1 arcsec from the refined XRT position (GCN Circ. 6990) and 0.7 arcsec from the optical afterglow found by ROTSE-III at McDonald Observatory (Rykoff et al., GCN Circ. 6987). The bright X-ray light-curve can be fitted by a broken power-law, with an initial steep decay index of 2.8 +/- 0.3 followed by a flatter decay index of 1.5 +/- 0.1 after a break at 260 +/- 20 seconds. The WT data (150-400 seconds) can be modelled as an absorbed power-law, with Gamma = 1.40 +/- 0.05 and a total absorbing column of NH = (0.9 +/- 0.1)e21 cm^-2, in excess of the Galactic value of 5.1e20 cm^-2. The 0.3-10 keV observed (unabsorbed) flux during this time is 2.0e-09(2.2e-09) erg cm^-2 s^-1. Assuming the source continues to decay with the same decay index of 1.5, we predict an XRT count rate of 7E-3 counts/s at T+24 hours, which corresponds to an observed flux of 4E-13 ergs cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6999 SUBJECT: GRB071025: Xinglong TNT I-band upper limit DATE: 07/10/25 17:51:37 GMT FROM: L.P. Xin at NAOC L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J. Wang , Y. Urata and W.K. Zheng on behalf of EAFON report: We have observed the field of GRB071025(C. Pagani , GCN 6986) with TNT 0.8m telescope at Xinglong observatory, started from 10:27:28.296 UT, about 6.3 hours after the burst. The wheter was not good. A series of I-band images were obtained, and no new source was found in our 18*240s combined image within the error region of the XRT(C. Pagani, GCN6986 GCN6990) and the locations reported by E.S. Rykoff(GCN 6987); S. Covino (GCN 6988); J. S. Bloom (GCN 6989;). the 3 sigma limit of our combined image derived from USNO-B1.0 Imag was I =18.2 mag at the mean time of 7.1 hours after the burst. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7000 SUBJECT: Swift UVOT upper limits DATE: 07/10/25 19:00:39 GMT FROM: Paul Kuin at MSSL N.P.M. Kuin (MSSL/UCL) and C. Pagani (PSU) report on behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 071025 (found with Swift BAT, as reported in GCN 6986 of Pagani et al.) beginning 2007-10-25 04:11:11 UT, 137 seconds after the burst trigger time. After a 10 s settling image in V, a 98 s finding chart exposure in the white filter was taken, followed by observations in all filters. No new source was found in any of the UVOT observations inside the reported position of the Swift XRT error circle (Pagani et al, GCN 6990, 6998) or the position of the detection of a transient source in the red bands of which the most accurate was the PARITEL observation in the J band (J. Bloom, GCN 6989), consistent with the refined XRT position. We report upper limits at position RA=23:40:17.078, DEC=+31:46:42.87 (J2000). The 3-sigma upper limits for detecting a source at the reported position in the co-added frames as determined are: Filter Tstart Tstop Exp Magnitude (s) (s) (s) (3-sigma UL) White 155 16016 1377 22.82 v 137 17760 1319 21.22 b 3968 11968 1194 22.14 u 3760 23536 2085 22.13 uvw1 3552 22704 2164 22.05 uvm2 4784 21808 1082 21.43 uvw2 4368 16928 1279 21.89 The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.074 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7001 SUBJECT: GRB071025: Optical Pre-imaging from Palomar DATE: 07/10/25 19:00:59 GMT FROM: Nat Butler at MIT/CSR P. Nugent (LBL), N. Butler, J.S. Bloom, and D. Perley (UC Berkley) report: We have created a stacked image through the co-addition of 12 unfiltered images taken by the NEAT collaboration and 45 images in the RG610 filter taken by the Palomar-Quest Consortium at the Palomar Oschin Schmidt telescope (obtained from 2001-2007), of 071025 (Pagani et al.; GCN #6986). The stacked image is significantly deeper than the DSS (3 sigma limit of R~22.8 mag). There is no source at the position of the counterpart (Rykoff et al. GCN #6987, Covino et al. GCN #6988, Bloom et al. GCN #6989). The image is available at http://www.lbl.gov/~nugent/deepsky.html This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7002 SUBJECT: GRB 071025A: Complex Early-Time IR Behavior, Simultaneous with Gamma- and X-rays DATE: 07/10/25 20:40:25 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom, N. R. Butler, D. A. Perley, D. L. Starr, R. Foley (UC Berkeley) report: "We obtained simultaneous J, H, and Ks band images with fine time sampling (7.8s cadence) of the afterglow (Rykoff et al. 6987; Covino et al. 6988) of GRB 070125A (Pagani et al. 6986) with PAIRITEL (*) beginning ~200s after the BAT trigger. The beginning of the observations coincides with the fading tale of the prompt emission. The IR light curve initially rises, then exhibits two prominent peaks (at T+~500s and T+~1500s) before fading as a powerlaw t^{-1.5+/-0.1}, after t ~ 2000s. A refined data reduction and a search for potential color variations are in progress." This message may be cited. (*) http://pairitel.org ***************************************************** Joshua Bloom Assistant Professor, UC Berkeley 601 Campbell Hall, Berkeley, CA 94720 (510) 643-3839 [Office] 447 Campbell (510) 643-4621 [Lab] 260 Evans http://astro.berkeley.edu/~jbloom ***************************************************** //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7003 SUBJECT: GRB 071025: SQIID JHK photometry DATE: 07/10/25 22:43:19 GMT FROM: Xiaohui Fan at U of Arizona L. Jiang, F. Bian, X. Fan (Steward Observatory, University of Arizona) reports: Using the Simultaneous Quad Infrared Imaging Device (SQIID) on the Kitt Peak Mayall 4-meter Telescope, we observed GRB 071025 in J, H, K bands simultaneously, beginnig at UT 2007-10-25-05:56:59. With total exposure time of 240 sec in all three bands, we clearly detected the afterglow. Calibrated using local 2MASS sources, the object is at J=17.34 +/- 0.05 H=16.37 +/- 0.05 K=15.45 +/- 0.05 The photometric errors are dominated by the zeropoint uncertainties from our calibration procedure. The photon noise on the measuremens is <0.01. The message may be cited. Xiaohui Fan Steward Observatory The University of Arizona 933 N. Cherry Ave. Tucson, AZ 85721-0065 Email: fan@as.arizona.edu Tel: (520) 626-7558 Fax: (520) 621-1532 URL: http://sancerre.as.arizona.edu/~fan //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7004 SUBJECT: GRB 071025 Milagro GeV/TeV Observations DATE: 07/10/25 23:08:35 GMT FROM: Pablo Saz Parkinson at UCSC/Milagro Pablo Saz Parkinson (UC Santa Cruz) on behalf of the Milagro collaboration reports: We have searched Milagro data for emission at GeV/TeV energies from GRB 071025 detected by Swift (GCN Circ 6986, C. Pagani et al.), during the main period of emission lasting 422s (GCN Circ 6996, S. D. Barthelmy et al.). No evidence for prompt GeV/TeV emission was found. TeV photons are attenuated by pair production with infrared photons in intergalactic space. We calculate uppers limits using the extragalactic infrared background light (EBL) absorption model of Primack et al. 2005 (AIP Conf. Proc. 745, p. 23). A preliminary analysis, assuming a differential photon spectral index of -2.4, gives upper limits on E^2dN/dE at 99% confidence of: E^2 dN/dE at 200 GeV < 1.4 * 10^(-6) erg cm^(-2) (Assuming z=0) and E^2 dN/dE at 200 GeV < 2.3 * 10^(-5) erg cm^(-2) (Assuming z=0.5) E^2 dN/dE at 200 GeV < 2.0 * 10^(-3) erg cm^(-2) (Assuming z=2.0) These upper limits are preliminary and will be refined with further analysis. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7005 SUBJECT: GRB 071025: SARA VRI upper limits DATE: 07/10/26 02:59:27 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike, Dieter H. Hartmann (Clemson University), Evan Bryson, Matt Cefalu, and Todd Hillwig (Valparaiso University) report on behalf of the Clemson GRB Follow-Up Team: We observed the field of GRB 071025 (GCN 6986, Pagani et al.) with the 0.9m SARA telescope on Kitt Peak beginning 49 minutes after the trigger. Our observations consisted of R, V, and I band exposures under good weather conditions. We do not detect the afterglow (GCN 6987, Rykoff et al.) in any of our stacked images. Times are given in days after the trigger. R and I magnitudes were determined based on calibration to 10 USNO B1.0 field stars. V magnitudes were found relative to 5 NOMAD field stars. Start time End time Exp Mag ---------------------------------------------------------- 0.03394 0.04328 4x180s R > 18.6 0.04405 0.05559 2x180s + 2x240s V > 19.1 0.05586 0.10521 10x240s I > 19.3 The SARA website may be found at http://astro.fit.edu/sara/sara.html. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7008 SUBJECT: GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior DATE: 07/10/26 22:22:52 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P.R. Wozniak, R. White, H. Davis of Los Alamos National Laboratory report: Our Raptor telescopes responded to Swift trigger 295301 (Pagani et al., GCN 6986) at 04:10:14.0 UT, 80.3 seconds after the trigger and 4.2 seconds after receiving the GCN packet. We detect faint optical emission from the counterpart reported by the ROTSE team (Rykoff et al., GCN 6987 and Covino et al., GCN 6988). We observe the first optical peak reported by Rykoff et al. (GCN 6992) at T+~600s. The counterpart then fades until T+~1200s. The optical lightcurve then rebrightens to a peak near T+~1400s at about the level of the previous peak. This "twin peaks" behavior seems to be consistent with the IR behavior reported by Bloom et al. (GCN 7002). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7011 SUBJECT: GRB 071025: Kuiper Telescope Optical Observations DATE: 07/10/27 19:49:05 GMT FROM: Grant Williams at Steward Observatory P. A. Milne (Steward Observatory) and G. G. Williams (MMTO), on behalf of the Super-LOTIS Collaboration, report: The 1.54m Kuiper telescope began observations of the error region of GRB 071025 (Swift trigger 295301, Pagani et al. GCN 6986) at 04:37:08 UT, approximately 28 minutes after the trigger. Observations were obtained in the V, R, and I-bands. The afterglow first reported by Rykoff et al. (GCN 6987) is clearly visible in the individual early R and I band images but not in the V-band images or in the sum of the V-band images. Observations continued until 09:47:09 UT. The aperture photometry results below were obtained from sums of individual images using nearby stars in the USNO-B1.0 and NOMAD catalogs. Further analysis of additional epochs is continuing. Filter UT-Start UT-End exp (s) magnitude error R ---- 04:37:08 ----- 04:41:30 ---- 150 --- 18.7 +/- 0.1 R ---- 04:42:14 ----- 05:02:40 ---- 1080 -- 19.3 +/- 0.1 R ---- 05:03:12 ----- 05:24:11 ---- 1080 -- 19.8 +/- 0.1 V ---- 05:43:38 ----- 06:07:46 ---- 1200 -- < 22.0 I ---- 05:25:05 ----- 05:42:39 ---- 960 -- 18.2 +/- 0.1 I ---- 08:01:20 ----- 08:55:41 ---- 3000 -- 19.9 +/- 0.15 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7018 SUBJECT: GRB071025: Optical+NIR observations DATE: 07/10/29 23:02:05 GMT FROM: Paul Price at IfA,UH T. Minezaki (IoA, Tokyo), P.A. Price (IfA, Hawaii), Y. Yoshii (IoA, Tokyo), L. Cowie (IfA, Hawaii) and Y. Kakazu (IfA, Hawaii) report: We observed the optical afterglow of GRB071025 with the robotic MAGNUM telescope + MIPS dual-beam imager. We find a fading source in each of the RIYJHK bands at the position reported by Bloom et al. (GCN 6989): Filter midtime(UTC) Exp. time magnitude/upper limits J 2007-10-25 06:59 10 17.73 +- 0.06 R 2007-10-25 07:01 10 21.5 +- 0.4 Y 2007-10-25 07:21 9 detected I 2007-10-25 07:21 10 19.97 +- 0.13 K 2007-10-25 07:43 8 16.67 +- 0.07 R 2007-10-25 07:43 10 > 20.9 H 2007-10-25 08:04 9 17.59 +- 0.08 I 2007-10-25 08:04 10 20.3 +- 0.2 J 2007-10-25 08:25 9 18.29 +- 0.10 R 2007-10-25 08:25 10 > 21.0 Y 2007-10-25 08:44 9 marginally detected I 2007-10-25 08:44 10 20.5 +- 0.3 The magnitude and the 3-sigma upper limits were derived using the USNO-B1.0 and 2MASS catalogues. The magnitude error does not include the error of the calibration source. The Y-band observations have not been calibrated. This message may be cited.