GRB 971227 optical observations: #017 Paul Groot, Titus Galama (Univeristy of Amsterdam), Jan van Paradijs (UoA and University of Alabama in Hunstville), Chryssa Kouveliotou (USRA at NASA/MSFC), Nic Walton, (ING La Palma), Penny Sackett (Groningen), Arlin Crotts (Columbia University, NY), Simone Bianchi and Jonathan Davies (Cardiff, UK) report: "Visual comparison of optical R-band observations made on December 28.237 UT (1800s) and December 29.108 UT (900s) with the 2.5m Isaac Newton Telescope at La Palma of the inner 12'x12' region of the SAX WFC errorbox of GRB971227 shows no obvious varying object. Preliminary photometry shows that this corresponds to an upper limit on variability of 0.3 mags down to a limiting magnitude of R=22.8" This message is citeable. /////////////////////////////////////////////////////////////////////////////// Circular No. 6796 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 A. Coletta, G. Gandolfi, and M. Smith, BeppoSAX Science Operation Center, Telespazio, Rome; L. Piro, M. Cinti, and P. Soffitta, Istituto di Astrofisica Spaziale, CNR, Rome; and J. Heise, Space Research Organisation, Utrecht, report on behalf of the BeppoSAX team: "A gamma-ray burst (Bacodine trigger 6546) has been detected by the BeppoSAX Gamma-Ray burst Monitor on Dec. 27.34938 UT. A quick-look analysis shows a structured gamma-ray burst lasting about 10 s with a peak flux of 630 counts/s. The gamma-ray burst has been detected also by the Wide Field Camera WFC2 with a peak flux of about 1.8 Crab. The position given by the quick-look analysis is R.A. = 12h57m29s, Decl. = +59o16'.3 (equinox 2000.0). The event was detected in a part of the orbit when the satellite was not in an optimal pointing configuration, resulting in an estimated error radius of 10'. A BeppoSAX Narrow Field follow-up observation is in progress. Observations at all wavelengths are urged." (C) Copyright 1997 CBAT 1997 December 29 (6796) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// BATSE BURST TRIGGER NO.: 6546 TIME: TJD=0809 SECONDS=30186 TYPE: BURST SOLAR FLARE TRIGGER SIGNAL:N SIGNIFICANCE: SIGMA INTENSITY: COUNTS/CM2 LOCATION: ZENITH=117 AZIMUTH=84.5 ERROR=1.66 DEGREES COMMENTS: BURST, DOUBLE PULSE, DUR. APPROX. 7 SECS, STARTS AT APPROX. T-3.5 SECS, MAX. AT APPROX. T+0.7 SECS. NOT VISIBLE ABOVE 300 KEV. /////////////////////////////////////////////////////////////////////////////// GRB 971227: #018 A. J. Castro-Tirado* and J. Gorosabel, Laboratorio de Astrofisica Espacially Fisica Fundamental (LAEFF-INTA), Madrid J. Greiner, Astrophysikalisches Institut (AIP), Potsdam M. R. Zapatero-Osorio, Instituto de Astrofisica de Canarias (IAC), Tenerife and E. Costa, Istituto di Astrofisica Spaziale, Frascati (on behalf of the BeppoSAX team) Report: following the detection of GRB 971227 by BeppoSAX, R-band images were obtained by Y. Aguilar and R. Kohley (Sternwarte der Universitat, Bonn) with the 2.2-m CAHA telescope (+CAFOS) at the German- Spanish Calar Alto Observatory, on Dec 27.91, Dec 28.16 and Dec 29.12 . A careful visual inspection of the three frames reveals no variable object (by more than 0.5 mag) above a R = 21.5 limiting magnitude within the entire BeppoSAX WFC error box (8' radius). Further observations are in progress. * ajct@laeff.esa.es - though not easily reachable by e-mail from Dec 30 to Jan 10. /////////////////////////////////////////////////////////////////////////////// Circular No. 6797 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 L. Piro and P. Soffitta, Istituto Astrofisica Spaziale, CNR, Rome; R. C. Butler, Agenzia Spaziale Italiana, Rome; L. A. Antonelli, F. Fiore, and M. Capalbi, BeppoSAX Science Data Center, Rome; A. Tesseri and V. Torroni, BeppoSAX Science Operation Center, Telespazio, Rome; and C. De Libero, BeppoSAX, Operation Control Center, Telespazio, Rome, report on behalf of the BeppoSAX team: "A follow-up observation of GRB 971227 was carried out with BeppoSAX 14 hr after the initial burst. Two previously unknown x-ray sources were detected within the WFC error circle (IAUC 6796) in the MECS x-ray telescopes. 1SAX J1257.5+5915 is located at R.A. = 12h57m33s, Decl. = +59o15'27" (equinox 2000.0; error radius about 1'.5, including systematics in the position reconstruction and statistical errors). Three radio sources of the NRAO/VLA Sky Survey catalogue (cf. http://www.cv.nrao.edu/~jcondon/nvss.html) lie within this error circle; the strongest one has a flux of 20 mJy at 1.4 GHz and is polarized. The x-ray source does not show any significant variation during the 20-hr observation. The average countrate in the range 1.3-10 keV was 0.0012 +/- 0.0004 counts/s for two MECS units, corresponding to a 2-10-keV flux of 1 x 10E-13 erg cmE-2 sE-1. The other source, 1SAX J1257.3+5924, was detected at R.A. = 12h57m15s, Decl. = +59o24'02". The countrate in the first 8 hr of the observation was 0.0032 +/- 0.001 counts/s, which corresponds to a 2-10-keV flux of 3 x 10E-13 erg cmE-2 sE-1. In the following part of the observation, the source was not detected, with a 3-sigma upper limit of 0.002 counts/s. We conclude that 1SAX J1257.3+5924 is the best candidate for the x-ray afterglow of GRB 971227." (C) Copyright 1997 CBAT 1997 December 29 (6797) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// H. S. Park* #019 on behalf of the LOTIS collaboration: R. Bionta, E. Ables, L. Ott, E. Parker (LLNL) G. Williams, D. Hartmann (Clemson University) S. Barthelmy, P. Butterworth, N. Gehrels, T. Cline (NASA/GSFC) C. Kouveliotou, J. Fishman, C. Meegan (NASA/MSFC) D. Band (U.C. San Diego) K. Hurley (U. C. Berkeley) D. Ferguson (CalState, Hayward) "LOTIS (the Livermore Optical Transient Imaging System), an automated, wide-field-of-view telescope system dedicated to the search for simultaneous GRB optical counterparts, was on-line on the night of Dec. 27 when BATSE detected GRB971227. LOTIS received GCN coordinates derived from BATSE telemetry approximately 4 seconds after the start of the burst and obtained its first 10 second exposure, centered on the GCN coordinates 6 seconds later (10 sec after the burst began: 27.3495 UT) LOTIS continued taking 10 second exposures at the rate of 1 image every 20 seconds for the next 20 minutes, then at the rate of once per minute for the rest of the night. Because of LOTIS's large, 17.4 x 17.4 degree field of view, the recorded images fully contain the error box of the location of the associated x-ray transient detected by BeppoSAX's NFI despite the 6.7 degree difference between the location of the BeppoSAX NFI position and the GCN BATSE-Original coordinates. A computer-aided visual examination of the area within the BeppoSAX NFI/WFC position error circle (8' radius) revealed 10 objects brighter than a visual magnitude of mV ~ 12.3 +/- 0.3; all of which were identified with known objects in the Guide Star Catalog and the Digital Sky Survey, and none showing variations in brightness. Further analysis is in progress." *hpark@llnl.gov /////////////////////////////////////////////////////////////////////////////// Circular No. 6798 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 P. M. Woods, University of Alabama in Huntsville; C. Kouveliotou, Universities Space Research Association; and G. J. Fishman, Marshall Space Flight Center, NASA, report on behalf of the BATSE Team: "GRB 971227 (IAUC 6796, 6797) was recorded as BATSE trigger No. 6546. It was a weak, short event of duration about 6 s that exhibits two well distinguished peaks, separated by 2.5 s. The burst fluence (above 25 keV) was 9.3 (+/- 1.4) x 10E-7 erg cmE-2 and its peak flux (between 50 and 300 keV) was 3.3 +/- 0.2 photons cmE-2 sE-1. The burst was not detected above 300 keV." (C) Copyright 1997 CBAT 1997 December 30 (6798) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// GRB 971227 #020 A. J. Castro-Tirado and J. Gorosabel, Laboratorio de Astrofisica Espacial y Fisica Fundamental, Madrid J. Greiner, Astrophysikalisches Institut, Potsdam M. R. Zapatero-Osorio, Instituto de Astrofisica de Canarias, Tenerife and E. Costa, Istituto di Astrofisica Spaziale, Frascati (on behalf of the BeppoSAX team) Report: following the detection of GRB 971227 by BeppoSAX and BATSE (IAUC 6796, 6798), R-band images were obtained by Y. Aguilar and R. Kohley (Sternwarte der Universitat, Bonn) with the 2.2-m CAHA telescope (+CAFOS) at the German-Spanish Calar Alto Observatory. Only the image taken on Dec 27.91 includes the entire error box of 1SAX J1257.3+5924, presumably the GRB 971227 X-ray afterglow (IAUC 6797). An object with R = 19.5 (preliminary magnitude) at the edge of the 16' field of view and inside the 1SAX J1257.3+5924 error box, is seen on the Dec 27.91 image, but it is not present on the images taken on Dec 30.16 at Loiano (see below), above a limiting magnitude R = 20.5. Its position is AR(2000) = 12 57 10.6, Dec(2000) = +59 24 43 (+/- 3"). An identification-chart can be obtained via anonymous ftp at laeff.esa.es under /pub/users/ajct/grb971227. Deeper observations are encouraged in order to confirm whether this is the optical counterpart of GRB 971227. C. Bartolini, A. Guarnieri, M. Lolli, A. Piccioni and F. Zavatti, Universita di Bologna, Communicate: the object proposed by Castro-Tirado et al (this Circ.) is undetectable on our R frames on Dec 30.16 which were taken at the 1.5m telescope of the Bologna Astronomical Observatory in Loiano. The object was therefore fainter than R=20.5 (mag limit of the images, preliminary value). Data reduction is in progress. Deeper imaging is highly recommended. /////////////////////////////////////////////////////////////////////////////// Circular No. 6800 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 A. J. Castro-Tirado and J. Gorosabel, Laboratorio de Astrofisica Espacial y Fisica Fundamental, Madrid; J. Greiner, Astrophysikalisches Institut, Potsdam; M. R. Zapatero-Osorio, Instituto de Astrofisica de Canarias, Tenerife; and E. Costa, Istituto di Astrofisica Spaziale, Frascati (on behalf of the BeppoSAX team) report: "Following the detection of GRB 971227 by BeppoSAX and BATSE (IAUC 6796, 6798), R-band images were obtained by Y. Aguilar and R. Kohley (Sternwarte der Universitat, Bonn) with the 2.2-m CAHA telescope (+ CAFOS) at the German-Spanish Calar Alto Observatory. Only the image taken on Dec. 27.91 UT includes the entire error box of 1SAX J1257.3+5924, presumably the GRB 971227 x-ray afterglow (IAUC 6797). An object with R = 19.5 (preliminary magnitude) at the edge of the 16' field-of-view, and inside the 1SAX J1257.3+5924 error box, is seen on the Dec. 27 image at R.A. = 12h57m10s.6, Decl. = +59o24'43" (equinox 2000.0; uncertainty +/- 3"), but it is not present on images taken on Dec. 30 at Loiano (see below), to a limiting magnitude of R = 20.5. An identification chart can be obtained via anonymous ftp at laeff.esa.es under /pub/users/ajct/grb971227. Deeper observations are encouraged in order to confirm whether this is the optical counterpart of GRB 971227." C. Bartolini, A. Guarnieri, M. Lolli, A. Piccioni, and F. Zavatti, Universita di Bologna, communicate: "The object proposed by Castro-Tirado et al. (above) is undetectable on our R frames on Dec. 30.16, which were taken at the 1.5-m telescope of the Bologna Astronomical Observatory in Loiano. The object was therefore fainter than R = 20.5 (mag limit of the images, preliminary value). Data reduction is in progress. Deeper imaging is highly recommended." (C) Copyright 1997 CBAT 1997 December 30 (6800) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// Optical Observations for GRB971227 #021 T.J. Galama, P.J. Groot (University of Amsterdam), T. von Hippel (University of Wisconsin) and A. Diercks (University of Washington, Seattle), J. van Paradijs (UoA and University of Alabama in Huntsville), C. Kouveliotou (USRA at NASA/MSFC) report: "R-band observations of the proposed OT to GRB971227 (Castro-Tirado et al., IAUC 6800) taken with the Kitt Peak 0.9m telescope at December 29.53 UT and the 3.5m Apache Point Telescope at December 30.44 UT show this object at a constant level of R=20.4 +/- 0.1 mag, at a position RA=12h57m08.65s, Dec=+59d24'40" (J2000). It is 1.4 magnitudes fainter than a relatively bright (R=19.0) star located at RA=12h57m04.8s, Dec=+59d24'42.0" (J2000). Both object appear in the Digital Sky Survey with a relative magnitude difference comparable to this value. In the Apache Point image the source appears to be slightly extended, which indicates it may be a galaxy. No object in the SAX NFI errorbox (Piro et al., IAUC 6797) appears to vary at a level of more than 0.3 mag, down to a limiting magnitude of R=21.5". Please direct communications to paulgr@astro.uva.nl /////////////////////////////////////////////////////////////////////////////// Howard E. Bond (Space Telescope Science Institute) #022 David Balam (University of Victoria) Kailash C. Sahu (Space Telescope Science Institute) report: There seems to have been some confusion about possible optical counterparts of GRB 971227 in recent GCN e-mails. We believe that this is because THREE different optical objects have been mentioned in recent communications, as follows: Object RA (J2000) Dec Remarks 1 12h57m10.6s +59o24'43" proposed as GRB counterpart by Castro-Tirado et al., IAUC 6800 2 12h57m08.6s +59d24'40" described as non-variable at R=20.4 by Galama et al. (GCN notice Dec 31) based on KPNO and APO data 3 12h57m04.8s +59d24'42" reference star with R=19.0 used by Galama et al. We note that objects 1 and 2 ARE NOT IDENTICAL. Object 2 is in fact faintly visible on direct examination of POSS-II films, in accordance with the above report of non-variability. Object 1 is NOT visible on POSS-I prints nor the POSS-II films. A 630-sec CCD R-band exposure on the field was obtained on 1997 Dec 31.44 by D. Balam under poor observing conditions with the 1.8-m Plaskett reflector of the Dominion Astrophysical Observatory; the limiting magnitude (S/N=3) is R=20.5 (assuming Object 3 to have R=19.0). Object 2 is faintly visible, in accordance with the above. Object 1, visible at R=19.5 in a Calar Alto image of Dec 27.91 posted on the WWW by Castro-Tirado et al. (see IAUC 6800), and reported as NOT seen above R=20.5 on Dec 30.16 by Bartolini et al. (GCN notice, Dec 30), is likewise NOT visible above R=20.5 in Balam's image of Dec 31.44. This observation would appear to strengthen the reported variability of Object 1 and its identification with the GRB afterglow. Deeper images should urgently be obtained and monitoring should continue. /////////////////////////////////////////////////////////////////////////////// GRB971227: #023 Dave Balam additionally reports: A precise optical position of Object 3 in our previous report has been determined as follows: 12h 57m 04s.93 +59o 24' 39".1 (J2000) The astrometric solution was obtained using 17 USNO catalog stars, m.e. 0".41 (RA) and 0".32 (Dec) [The "previous report" referred to above is attached below for reference. SDB] -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Howard E. Bond (Space Telescope Science Institute) David Balam (University of Victoria) Kailash C. Sahu (Space Telescope Science Institute) report: There seems to have been some confusion about possible optical counterparts of GRB 971227 in recent GCN e-mails. We believe that this is because THREE different optical objects have been mentioned in recent communications, as follows: Object RA (J2000) Dec Remarks 1 12h57m10.6s +59o24'43" proposed as GRB counterpart by Castro-Tirado et al., IAUC 6800 2 12h57m08.6s +59d24'40" described as non-variable at R=20.4 by Galama et al. (GCN notice Dec 31) based on KPNO and APO data 3 12h57m04.8s +59d24'42" reference star with R=19.0 used by Galama et al. We note that objects 1 and 2 ARE NOT IDENTICAL. Object 2 is in fact faintly visible on direct examination of POSS-II films, in accordance with the above report of non-variability. Object 1 is NOT visible on POSS-I prints nor the POSS-II films. A 630-sec CCD R-band exposure on the field was obtained on 1997 Dec 31.44 by D. Balam under poor observing conditions with the 1.8-m Plaskett reflector of the Dominion Astrophysical Observatory; the limiting magnitude (S/N=3) is R=20.5 (assuming Object 3 to have R=19.0). Object 2 is faintly visible, in accordance with the above. Object 1, visible at R=19.5 in a Calar Alto image of Dec 27.91 posted on the WWW by Castro-Tirado et al. (see IAUC 6800), and reported as NOT seen above R=20.5 on Dec 30.16 by Bartolini et al. (GCN notice, Dec 30), is likewise NOT visible above R=20.5 in Balam's image of Dec 31.44. This observation would appear to strengthen the reported variability of Object 1 and its identification with the GRB afterglow. Deeper images should urgently be obtained and monitoring should continue. /////////////////////////////////////////////////////////////////////////////// Optical Observations on GRB971227: #024 A. N. Ramaprakash, S. R. Kulkarni, S. G. Djorgovski, R. R. Gal (Caltech), and S. Perlmutter and B. Grossan (UCB/LBL), report on behalf of the Caltech GRB collaboration: "We have analyzed R-band images of the field of 1SAX J1257.3+5924, proposed as the x-ray counterpart of GRB 971227, obtained at the Keck-II telescope, on UT 1997 Dec 30.8 and UT 1998 Jan 01.8. Our analysis shows no objects brighter than R = 23 mag which have varied significantly by more than 0.2 mag over this 2-day interval (conservative limits). For comparison, a source declining with a standard 1/t power-law would have faded by about 0.5 mag in the same time interval. This upper limit is at least a factor of 10 fainter than the optical transient associated with GRB 970508 at the same relative epoch. In addition, we have obtained r-band images at Palomar 60-inch telescope on UT 1997 Dec 28.4, covering about 80 percent of the 1.5-arcmin radius error circle quoted for the x-ray source. They show no objects brighter than about R = 21 mag which were not also detected in the subsequent Keck images. More refined analysis is in progress." This message may be cited. Please send any comments to Shri Kulkarni (srk@astro.caltech.edu). /////////////////////////////////////////////////////////////////////////////// Optical Observations of the GRB971227 field: #025 S. G. Djorgovski, S. R. Kulkarni, A. N. Ramaprakash, (Caltech), and D. Frail (NRAO) report on behalf of the Caltech GRB collaboration: "There has been some confusion regarding various objects in the field of 1SAX J1257.3+5924, the proposed x-ray counterpart of GRB 971227. Keck R-band images of the field (obtained on UT 1997 Dec 30.8, limiting magnitude R ~ 25.5) can be obtained at the following URL: http://astro.caltech.edu/~george/grb/grb971227.html There we mark several objects, whose positions (good to 0.4 arcsec, on the basis of USNO A1.0 catalog) are: Object type RA(J2000) DEC(J2000) R mag A star 12 57 13.68 +59 23 36.7 19.1 B star 12 57 11.15 +59 24 45.4 22.1 C galaxy 12 57 08.74 +59 24 35.7 20.6 D star 12 57 04.95 +59 24 39.2 19.4 E galaxy 12 57 08.22 +59 24 52.4 21.4 F galaxy 12 57 08.30 +59 25 00.5 21.25 The magnitudes have been zero-pointed using a set of APM objects in the field; the zero-point is uncertain by at least 0.2 mag. Star B is the closest object to the detection claimed by Castro-Tirado et al. (GCN 30Dec97 [#020], and IAUC 6800), even though it is 4.8 arcsec away from their estimated position. In particular, no object was detected within their nominal (3 arcsec radius) error circle down to a magnitude of R ~ 24 or even fainter in the Keck images of Dec 30.8 UT. Star B remains constant in brightness over the time span of our data (cf. our earlier GCN note [#024]), and indeed we detect no significantly variable objects in the entire error circle of the x-ray source down to the limits of our data. If the detection claimed by Castro-Tirado et al. was real, it would imply a fading with a power-law slope of t^(-2.5) or steeper. D is the comparison star mentioned by Galama et al. (GCN 31Dec97 [#021]), even though it is about 3 arcsec away from their quoted position, and galaxy C is almost certainly the object they propose as the possible identification of the claimed detection by Castro-Tirado et al. A is a convenient comparison/offset star. E and F are random galaxies in the same area, also given here as comparisons. We conclude that there is thus far no evidence for an optical transient associated with this gamma-ray burst down to significantly faint magnitude limits, similar to the cases of GRB 970815 and 970828. This message can be cited." [GCN Operator's Note: I have attempted to correct a developing problem of how to refer to earlier GCN Messages by retroactively adding serial numbers to the messages contained in the archive files. I have also added the appropriate numbers to the three messages referenced in the above message -- that would be the numbers in square brackets [#0nn]. Starting with this GCN Message, unique serial numbers will be added for reference purposes; however, it is still wise to refer to the first author as well as the number.] /////////////////////////////////////////////////////////////////////////////// GRB971227: #026 T.J. Galama, P.J. Groot (University of Amsterdam), S. Bianchi and J. Davies (Cardiff), T. von Hippel (University of Wisconsin) and A. Diercks (University of Washington, Seattle), J. van Paradijs (UoA and University of Alabama in Huntsville), C. Kouveliotou (USRA at NASA/MSFC) report: "As noted by many, the identification (GCN #21) of a galaxy with the optical counterpart to GRB971227 proposed by Castro-Tirado et al (GCN note #20, IAUC 6800), is incorrect. The galaxy is unrelated to the proposed counterpart. We sincerely apologize for the confusion this has caused to the community. Comparison of the images taken with the Kitt Peak 0.9m telescope at Dec. 29.53 UT, the Apache Point Observatory 3.5m Telescope at Dec 30.44 UT and a 2700s exposure with the 2.5m Isaac Newton Telescope at La Palma at Jan 03.10 UT of the region around the proposed OT, shows no variable object at a level of more than 0.3mag down to R=21.5. Please direct communications to paulgr@astro.uva.nl [GCN Operator's Note: The archive of GCN Messages for GRB971227 can be found at: http://gcn.gsfc.nasa.gov/gcn/other/971227.gcn3] /////////////////////////////////////////////////////////////////////////////// Circular No. 6803 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 S. A. Ilovaisky and C. Chevalier, Observatoire de Haute- Provence (OHP), write: "R-band CCD images of the SAX error box reported on IAUC 6797 were obtained with the 1.2-m OHP telescope on Jan. 3.14 UT. Analysis of the resulting median frame of three 30- min exposures shows no object at the position reported by Castro- Tirado et al. (IAUC 6800) down to a limiting R_c magnitude slightly fainter than 22. A group of faint galaxies with R_c about 21.5 appears a few arcsec northwest of that position." (C) Copyright 1997 CBAT 1997 January 6 (6803) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// Circular No. 6806 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 J. Mendez, Isaac Newton Group (ING), La Palma, and University of Barcelona (UB); P. Ruiz-Lapuente, UB; and N. Walton, ING, report: "We used the 2.5-m Isaac Newton Telescope at the Observatorio del Roque de los Muchachos to survey the field of GRB 971227, using the Wide Field Camera in the (RGO) I band. We did not detect the GRB afterglow previously reported (IAUC 6800), down to a limiting mag I = 22, ten days after the burst (Jan. 6.1 UT). We note an extended object (possibly a faint galaxy) located 15" west and 3" south of the position of the GRB reported by Castro-Tirado et al. (ibid.). Our images are available at http://www.ing.iac.es/~jma/grb971227.gif." (C) Copyright 1998 CBAT 1997 January 13 (6806) Daniel W. E. Green /////////////////////////////////////////////////////////////////////////////// Near-IR follow-up on GRB971227: #028 Message from: S. Klose, Thueringer Landessternwarte Tautenburg, Germany, klose@tls-tautenburg.de The 1.5 arcmin radius error box of GRB 971227 (Piro et al., IAUC 6797) was imaged with the Calar Alto 2.2-m telescope on January 9.1 UT using one of the MAGIC near-infrared cameras. The total integration time was 5000 seconds in the K'-band and 5000 seconds in the J-band, centered at RA, DEC (J2000) = 12:57:15.0, 59:24:02. MAGIC was used in its wide-field mode giving a field of view of 415 times 415 arcsec. The sky was clear, but the sky conditions presumably not very photometric. Final images and final results of the data reduction will be published within about 2-4 weeks. Preliminary results of the image reduction can already be obtained via http://www.tls-tautenburg.de/research/grb.html. Both, the J and the K'-band image are obtained by combining 1000 frames taken at 5 overlapping positions. If the optical counterpart of the GRB afterglow is strongly affected by extinction, then the most promising candidates for the NIR counterpart might be very red and faint objects. Two such objects are visible in the GRB error box. Both have only a faint counterpart on the Keck R-band image published by Djorgovski et al. (GCN #025). Coordinates are (+/- 2"): Object A: RA, DEC (J2000) = 12:57:10.3, 59:24:14 Object B: RA, DEC (J2000) = 12:57:22.8, 59:23:48. A photometry has still not been performed, but one can guess that both objects might have K' = 19.0 +/- 1.0. The most promising object is object A. Currently, it seems unlikely that this is an artifact, but remind please, these are preliminary data. At the moment it is impossible to decide whether one object is physically related to GRB 971227, or whether both objects are only very red objects in the field. To be careful, one should assume the latter. ROSAT/HRI data could help. This message may be cited. Please send any communications to klose@tls-tautenburg.de /////////////////////////////////////////////////////////////////////////////// Circular No. 6807 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html Phone 617-495-7244/7440/7444 (for emergency use only) GRB 971227 Further to their item on IAUC 6803, S. A. Ilovaisky reports that the CCD image of the GRB 971227 field noted therein can be found at URL http://www.obs-hp.fr/~ilovaisky/grb.html. (C) Copyright 1998 CBAT 1998 January 15 (6807) Daniel W. E. Green