//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1237 SUBJECT: Type Ib/c SN2002ap (SN/GRB?) Radio Observations DATE: 02/02/01 04:39:22 GMT FROM: Edo Berger at Caltech E. Berger, S. R. Kulkarni, and D. A. Frail report on behalf of the Caltech-NRAO-CARA GRB collaboration: "On 2002, February 1.03 UT we used the VLA at 8.46 GHz to observe the position of the peculiar Type Ib/c SN2002ap in M74 (IAUC 7810 and 7811). We detect a radio source with a flux density of 375+/-30 microJy within 1" of the optical position of this supernova at coordinates (J2000): RA=01:36:23.920, DEC=15:45:12.867, with an uncertainty of approximately 10 milliarcsec in both coordinates. The optical spectrum of this SN is similar to that of SN1998bw, and there is some evidence that SN2002ap is a younger and/or more energetic version of SN1998bw (IAUC 7810). In view of the peculiar properties of this object, the radio detection, and the possible connection of SN 1998bw with GRB 980425, we urge further observations at all wavelengths." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1238 SUBJECT: Type Ib/c SN2002ap (SN/GRB?) DATE: 02/02/01 04:55:22 GMT FROM: Edo Berger at Caltech S. R. Kulkarni and E. Berger report on behalf of the Caltech-NRAO-CARA GRB collaboration: "The early detection of radio emission from SN 2002ap (GCN 1237) has a number of interesting ramifications. Given the distance modulus of M74 of 29.3, the absolute magnitude of the SN is -15.6, and given that the optical emission is still rising (IAUC 7810) it is safe to assume that we are seeing the SN before maximum. The optical spectroscopy suggests an age of 7 days based on analogy with SN 1998bw (IAUC 7811). Adopting this age and a typical expansion speed of 30,000 km/s the inferred brightness temperature in the 8.5 GHz band is 3x10^10 K using the 0.4 mJy detection of Berger, Kulkarni and Frail (GCN 1237). As in the case of SN 1998bw, such a high brightness temperature argues for mildly relativistic expansion (see Kulkarni et al. 1998, Nature, 395, 663). If so, we should expect strong X-ray emission from inverse Compton scattering of the optical SN photons as well as measurable angular diameter of 0.2 milliarcsecond, both of which are verifiable with Chandra and VLBA observations. In addition to these observations, high frequency (sub-mm and mm) observations are also required to find the synchrotron self absorption frequency, which is essential for calculating the energy in the relativistic blastwave (see Kulkarni et al. 1998, Nature, 395, 663). Finally, it would be worthwhile inspecting archival data from gamma-ray burst monitors from the past two weeks to search for a faint GRB in the same position." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1239 SUBJECT: SN 2002ap (hypernova / GRB ??): special list on VSNET DATE: 02/02/01 08:55:51 GMT FROM: Taichi Kato at Kyoto U Taichi Kato (Kyoto U.) write: Regarding SN 2002ap (hypernova / GRB ??), VSNET has prepared a special mailing list dedicated to SN 2002ap event. This mailing list deals with most up-to-date information of this supernova. Those who wish to subscribe to the list should send an e-mail with a message line SUBSCRIBE vsnet-campaign-sn2002ap to vsnet-adm@kusastro.kyoto-u.ac.jp Also a web page: http://www.kusastro.kyoto-u.ac.jp/vsnet/SNe/sn2002ap.html Regards, Taichi Kato VSNET Collaboration //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1240 SUBJECT: pre-SN2002ap (SN/GRB?) imaging of M74 DATE: 02/02/02 17:47:21 GMT FROM: Paul Vreeswijk at U of Amsterdam Stephen Smartt, Enrico Ramirez-Ruiz, Institute of Astronomy, Cambridge; and Paul Vreeswijk, University of Amsterdam, report: UBVI images of M74 were taken with the Wide Field Camera on the Isaac Newton Telescope in July 2001, as part of the INT Wide Field Survey. At RA=1:36:24.00, DEC=15:45:13.6 (J2000), consistent with the radio position of SN2002ap (GCN No. 1237) to within 1.3", we detect an object with B=21.6, V=21.2, I=20.5 (with errors +/- 0.2mag). This is a fairly faint object in these short (120s) exposures, and the object shows some inconclusive evidence of being extended. At the spatial resolution of the images (~50 pc) the object could be an unresolved small cluster or HII region, or a predominantly bright star on a variable background. Assuming it is a single star, a distance modulus of 29.5 to M74, and Galactic extinction estimates from Schlegel et al. (1998; E(B-V)=0.07), we estimate absolute magnitudes of M_B = -8.2, M_V = -8.5, M_I = -9.1. The colours B-V=0.3, V-I=0.6 and absolute magnitudes are consistent with a very luminous early to mid F-type supergiant. The bolometric luminosity is approximately 10**5.3 L_solar, which would place the star in the Luminous Blue Variable region of the HR-diagram (Humphreys & Davidson 1994, PASP, 704, 1025), and suggest an initial mass of around 40 M_sol. We currently have no estimate of the internal reddening in the host galaxy, however note that any significant extinction would make the star intrinsically bluer and more luminous. Further astrometry and image shape analysis are required to confirm that the progenitor object is stellar, and we encourage monitoring of this very interesting supernova at all wavelengths. For an image of M74 and BVI zooms of the region around SN2002ap, see: http://www.science.uva.nl/~pmv/m74sn2002ap.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1242 SUBJECT: SN2002ap (SN/GRB?) UBVRI Field Photometry DATE: 02/02/04 15:53:15 GMT FROM: Arne A. Henden at USNO/USRA A. Henden (USRA/USNO) reports on behalf of the USNO GRB team: We have acquired UBVRcIc all-sky photometry for an 11x11 arcmin field that is approximately centered on the position of supernovae SN2002ap with the USNOFS 1.0-m telescope on one photometric night. Since the supernovae is expected to brighten further, exposures were short so that no star in the field is saturated. We have placed the photometric data on our anonymous ftp site: ftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/sn2002ap.dat The current photometry has a potential external zero-point error of less than two percent. The astrometry in this file is based on linear plate solutions with respect to USNO-A2.0. The internal errors are less than 100mas. As conditions permit, this file will be extended to include more photometric nights. M74/NGC628 is a very popular object to photograph since it is large, bright and beautiful. A causual search of the public archives for several observatories indicates that there are dozens of deep plates and CCD images of the galaxy, many of which will include the supernovae region. For example, two such V-band images at NOFS have approximately the same depth and resolution as the V-band image indicated by Smartt et al. (GCN 1240). A simple data-mining exercise should give a reasonable time history of any precursor over several decades. Towards that end, we will extend the photometry file down to about V=22 in the near future. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1244 SUBJECT: SN 2002ap (SN/GRB?) DATE: 02/02/05 17:55:39 GMT FROM: Paul Vreeswijk at U of Amsterdam P. Vreeswijk (University of Amsterdam) and S. Smartt (Institute of Astronomy, Cambridge) report that images taken by Gerry Gilmore and Rosie Wyse on the Isaac Newton Telescope, La Palma on Feb. 2.9 UT have allowed an accurate projection of the position of SN 2002ap on the pre-discovery images reported in IAUC 7816. Within the new errors, the SN is not coincident with the V = 21.2 object reported as a possible progenitor. The difference in position between SN 2002ap and this object is 1.7 +/- 0.3" where the error is dominated by the error in the position of the faint object. There is no object in the pre- discovery images at the SN position, to limiting magnitudes (5-sigma, 2" aperture radius) of U = 20.8, B = 22.1, V = 22.0, and I = 20.8. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1247 SUBJECT: SN2002ap (SN/GRB?) optical spectrographic observations DATE: 02/02/11 16:37:44 GMT FROM: Don Lamb at U.Chicago J. T. Lauroesch, D. G. York, C. Hastings, D. V. Bowen, D. Meyer, and D. Q. Lamb report: We obtained 75 minutes of integration (five 15-minute exposures) on SN2002ap using the echelle spectrograph (ARCES) on the Apache Point Observatory 3.5-meter telescope. The spectra were taken with a 1.6 arcsecond wide slit, 3.2 arcsec long, in seeing of about 1.5 arcsec. The spectra give complete spectral coverage from 3600 A to 10500A. The signal to noise ratio (per pixel) is about 20 at Ca II and 50 at Na I. These spectra, at a resolution of 8 km/s, show clear detections of interstellar NaI and CaII in both the Milky Way and M74. A weak, narrow, NaI feature (D1 and D2) is detected in M74 with a column density of approximately 2.5e11, suggesting there may be little cold interstellar gas in M74 in front of the SN. Assuming the "typical" Galactic relation between NaI and HI, this fact would suggest a total hydrogen column of approximately 5e19 in M74 along this sightline. Two components are seen in M74 in CaII; one narrow, corresponding in velocity to the NaI absorption noted above, and a second broader component, approximately +25 km/sec with respect to the Na I feature. The Ca II features each span roughly 50 km/sec, and are centered near 650 km/sec (heliocentric). The Galactic Na I and Ca II lines are about 5 times stronger that their M74 counterparts in the SN spectrum. This object, while it is still bright, is ideal for measuring interstellar abundances in the outer part of the M74 galaxy. This sightline passes near the location of a known Galactic high velocity H I cloud (Wakker 2001) at approximately -100 km/sec (LSR); however, no absorption is detected at these velocities in either Ca II or Na I to limits of 20 and 10 milli-Angstroms respectively. No other significant narrow absorption or emission lines were seen in the spectrum. Further observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1248 SUBJECT: SN2002ap (SN/GRB?) Echelle spectra DATE: 02/02/11 16:55:32 GMT FROM: Sylvio Klose at TLS Tautenburg Sylvio Klose, Eike Guenther, and Jens Woitas (Thueringer Landessternwarte Tautenburg) report: High-resolution spectra of SN 2002ap were aquired using the Echelle-spectrograph at the Tautenburg 2-m telescope on February 2.8 UT and 3.8 UT. The detector is a 2k x 2k CCD chip with 15 micron pixels. The spectral resolution was R = 70 000 (0.04 Angstrom per pixel; slit 1.04 arcsec). At the time of the observations SN 2002ap was at an apparent magnitude of about V=12. The spectra were reduced in a standard fashion. Wavelength calibration was performed by means of ThAr lamps. The signal-to-noise ratio of the combined images is about 30. This is sufficiently high to check the spectrum for lines from the interstellar medium in the supernova host galaxy (M 74). In the combined spectra we detect an absorption feature at a heliocentric velocity of (660 +/- 2) km/s what we attribute to redshifted NaI D1 at the velocity of the host [1, 2]. For the D1 component we measure an equivalent width of (30 +/- 5) milli-Angstrom, whereas the redshifted D2 component is blended with a telluric line. Assuming that the empirical relation between the equivalent width of Na I D1 and interstellar reddening in our Galaxy [3] is also representative for the interstellar medium in M 74 we arrive at a reddening in the supernova host of E(B-V) = (0.008 +/- 0.002) mag. Thus, assuming a ratio of total-to-selective extinction of about 3, our data are in agreement with A_V (host) = (0.025 +/- 0.005) magnitudes. In other words, at a projected distance of the supernova of about 13.5 kpc from the center of M 74 (assuming a distance of 10 Mpc, [4]), the supernova light is nearly unaffected by dust in M 74. References: [1] Tormen, G. & Burstein, D.: Astrophys. J. Suppl. Ser. 96 (1995) 123 [2] Smartt, S. & Meikle, P.: IAUC 7822 (2002) [3] Munari, F. & Zwitter, T.: Astron. Astrophys. 318 (1997) 269 [4] Chen, P. C. et al.: Astrophys. J. 395 (1992) L 41 The supernova spectrum is posted at http://www.tls-tautenburg.de/research/klose/SN2002ap.html . This message may be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1252 SUBJECT: IPN Upper Limits to a GRB Associated With SN2002ap DATE: 02/02/19 16:45:51 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team; E. Mazets, S. Golenetskii, on behalf of the Konus-Wind GRB team; C. Guidorzi, E. Montanari, F. Frontera, and M. Feroci, on behalf of the BeppoSAX GRBM team; G. Ricker, D. Lamb, S. Woosley, G. Crew, J. Doty, G. Monnelly, J. Villasenor, N. Butler, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, G. Pizzichini, N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Donaghy, C. Graziani, T. Tavenner, J-L Atteia, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE Team; I.Mitrofanov, D.Anfimov and M.Litvak on behalf on HEND/Odyssey GRB team; W. Boynton, C. Fellows, K. Harshman, and C. Shinohara, on behalf of the GRS/Odyssey GRB team; and T. Cline, on behalf of the Ulysses, Konus, and HETE GRB teams, report: We have searched for a gamma ray burst that might be associated with SN2002ap (Nakano, IAUC 7810), to investigate its similarity to the hypernova SN1998bw (Meikle et al. IAUC 7811). We have limited our search to data obtained between January 21 and January 29, 2002. During that period, no burst which could be localized by the IPN was found to have a source position in any way consistent with that of the supernova. That is, there was no event observed with two or more spacecraft that produced a source annulus or error box consistent with the supernova, and, although several events were observed each by single spacecraft in the network during this time, none of these unconfirmed events could be localized with any precision. Thus, lacking any definite evidence for an association, we quote only upper limits to a GRB from the direction of SN2002ap. These upper limits depend on the duration, spectrum, and arrival time within the search window, all of which are unknown. Each instrument in the network has a different sensitivity and duty cycle (determined by, among other things, the periods for which data were recovered, Earth-occultation for those spacecraft in low Earth orbit, Mars-occultation for the Mars Odyssey spacecraft, and the angle which the direction of SN2002ap made with the detector axis). For simplicity, we have assumed a 1 s long burst with a typical hard GRB spectrum to obtain the following fluence upper limits. We note that since SN2002ap is about 4 times closer than SN1998bw, then assuming that GRB980425 indeed originated in SN1998bw, a burst from SN2002ap might have been at least an order of magnitude more intense (neglecting beaming), and therefore easily detectable. 1. Ulysses. Duty cycle 95%. The Ulysses GRB detector has a quasi-isotropic response, so the arrival angle makes little difference. Upper limit: ~10^-6 erg/cm^2, 25-150 keV. 2. Konus. Duty cycle ~98%. The Wind spacecraft is several light-seconds from Earth, so the source was not occulted. Konus consists of two uncollimated right circular cylindrical detectors facing the north and south ecliptic poles. The ecliptic latitude of SN2002ap is approximately 5 degrees, so it is seen edge-on by the detectors. Upper limit: 5 x 10^-7 erg/cm^2, 20-2000 keV. 3. BeppoSAX GRBM. Complex response pattern and time-dependent duty cycle. Start date End date Duty Cycle 40-700 keV fluence, erg/cm^2 ------------------------------------------------------------------------ 20 Jan 06:32:49 21 Jan 13:00:00 47% 4 x 10^(-7) 21 Jan 13:00:00 22 Jan 14:41:09 0% (NO DATA) -- 22 Jan 14:41:09 22 Jan 20:00:58 36% 1 x 10^(-7) 22 Jan 20:00:58 24 Jan 17:00:00 0% (NO DATA) -- 24 Jan 17:00:00 25 Jan 09:35:00 42% 4 x 10^(-7) 25 Jan 09:35:00 29 Jan 23:59:59 0% (NO DATA) -- ------------------------------------------------------------------------ 4. HETE-FREGATE. Duty cycle 22%. The FREGATE instrument consists of four collimated right circular cylindrical detectors facing the anti-solar direction. SN2002ap made an angle of ~96 degrees to the detector axis, so any burst from it would not only have been observed edge-on, but also through the collimator. It would not have been observed by the WXM or the SXC. Nevertheless, bursts have been detected by FREGATE under precisely these non-ideal conditions. Sensitivity: 3.2 x 10^-6 erg/cm^2, 250-400 keV. The high energy range is due to the fact that the burst would have had to traverse the collimator. 5. Mars Odyssey HEND experiment. Duty cycle 64%. Sensitivity 10^-6 erg/cm^2 >60 keV. Many of these numbers are preliminary, and depend strongly on the assumptions about the time history, duration, arrival time, and spectrum of the assumed burst. More detailed information may be obtained from the people directly responsible for each experiment in the network. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1266 SUBJECT: Type Ic SN2002bl (SN/GRB?) Radio Observations DATE: 02/03/09 23:27:40 GMT FROM: Edo Berger at Caltech E. Berger, S. R. Kulkarni, and D. A. Frail report on behalf of the Caltech-NRAO-CARA GRB collaboration: "On 2002, March 8.26 UT we used the VLA at 4.86 and 8.46 GHz to observe the position of the peculiar type Ic SN2002bl in UGC 5499 (IAUC 7845). We detect no radio source at the position of the SN down to a 2-sigma limit of 0.1 mJy at both frequencies. The optical spectrum of SN2002bl shows that it is similar to the peculiar type Ib/c SN1998bw and SN2002ap approximately two weeks after the explosion (IAUC 7845). SN1998bw reached a peak flux of 50 mJy at 4.9 and 8.5 GHz on the same timescale. Given that the distance to SN2002bl (74 Mpc) is twice larger than the distance to SN1998bw, we determine that SN2002bl is at least 125 times fainter in the radio. On the other hand, SN2002bl can be up to 15 times brighter than SN2002ap (d=10 Mpc) which had a flux of approximately 0.4 mJy on a similar timescale (GCN 1237 and 1238; IAUC 7817). Based on the upper limit of 0.1 mJy, and adopting a typical expansion speed of 30,000 km/sec, we place an upper limit of 6x10^10 K on the brightness temperature of SN2002bl at 8.46 GHz." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1312 SUBJECT: SN 2002ap - peak brightness date (SN/GRB?) DATE: 02/03/28 10:57:54 GMT FROM: Eran Ofek at Tel Aviv U. A. Gal-Yam, E. O. Ofek, O. Shemmer report: Using the Wise Observatory 1m telescope we have obtained UBVRI photometry of SN 2002ap during February 2002. Using our most conservative estimate for the date of the $B-$band peak, Feb. $7.1_{-1.3}^{+7.6}$ days, and assuming that the lag between a hypothetical GRB (that might have been associated with this SN) and the time of $B-$band maximum is similar to that measured for SN 1998bw (14.3 days, Galama et al. 1998), we would expect the GRB trigger to have occurred around Jan. $23.8_{-1.3}^{+7.6}$ days. However, if we use instead our estimated $U-$band peak date, Feb. $4.7_{-1.9}^{+1.1}$ days, which is best constrained by our photometry, along with the appropriate $U-$band time lag from Galama et al. 1998 (13.7 days), the resulting GRB trigger time is Jan. $22.0_{-1.9}^{+1.1}$ days. Hurley et al. (GCN 1252) found no candidate GRB that might be associated with SN 2002ap in an intensive search of gamma-ray data from the IPN, starting Jan. 21. Our results suggest that the GRB trigger may have occurred outside the time frame searched. If the GRB-peak magnitude time lag for SN 2002ap was just one day longer than the lag measured for SN 1998bw, the trigger is likely to have been missed by Hurley et al. We conclude that in order to detect, or set a secure upper limit to the fluence of a GRB associated with SN 2002ap, a search similar to the one reported by Hurley et al. should be extended to include data taken several days prior to January 21. This message may be cited.