{
  "version": 2,
  "editedOn": 1777052503895,
  "bibcode": "2002GCN..1248....1K",
  "body": "Sylvio Klose, Eike Guenther, and Jens Woitas \n       (Thueringer Landessternwarte Tautenburg)\n\nreport:\n\n\nHigh-resolution spectra of SN 2002ap were aquired using the\nEchelle-spectrograph at the Tautenburg 2-m telescope on February 2.8 UT \nand 3.8 UT. The detector is a 2k x 2k CCD chip with 15 micron\npixels. The spectral resolution was R = 70 000 (0.04 Angstrom per\npixel; slit 1.04 arcsec). At the time of the observations SN 2002ap\nwas at an apparent magnitude of about V=12. The spectra were\nreduced in a standard fashion. Wavelength calibration was performed\nby means of ThAr lamps. The signal-to-noise ratio of the combined\nimages is about 30. This is sufficiently high to check the spectrum\nfor lines from the interstellar medium in the supernova host galaxy\n(M 74).\n\nIn the combined spectra we detect an absorption feature at a\nheliocentric velocity of (660 +/- 2) km/s what we attribute to\nredshifted NaI D1 at the velocity of the host [1, 2]. For the D1\ncomponent we measure an equivalent width of (30 +/- 5) milli-Angstrom,\nwhereas the redshifted D2 component is blended with a telluric line.\nAssuming that the empirical relation between the equivalent width of\nNa I D1 and interstellar reddening in our Galaxy [3] is also\nrepresentative for the interstellar medium in M 74 we arrive at a\nreddening in the supernova host of E(B-V) = (0.008 +/- 0.002)\nmag. Thus, assuming a ratio of total-to-selective extinction of about\n3, our data are in agreement with A_V (host) = (0.025 +/- 0.005)\nmagnitudes. In other words, at a projected distance of the supernova\nof about 13.5 kpc from the center of M 74 (assuming a distance of 10\nMpc, [4]), the supernova light is nearly unaffected by dust in M 74.\n\n\nReferences: \n\n[1] Tormen, G. & Burstein, D.: Astrophys. J. Suppl. Ser. 96 (1995) 123\n[2] Smartt, S. & Meikle, P.: IAUC 7822 (2002)\n[3] Munari, F. & Zwitter, T.: Astron. Astrophys. 318 (1997) 269\n[4] Chen, P. C. et al.: Astrophys. J. 395 (1992) L 41\n\nThe supernova spectrum is posted at \nhttp://www.tls-tautenburg.de/research/klose/SN2002ap.html .\n\nThis message may be quoted.",
  "circularId": 1248,
  "email": "klose@tls-tautenburg.de",
  "submitter": "Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>",
  "eventId": "SN 2002ap",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "subject": "SN2002ap (SN/GRB?) Echelle spectra",
  "createdOn": 1013446532000
}