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J/MNRAS/389/955     u'BVg'r'i'z' light curves of SN 2008ax   (Pastorello+, 2008)
The Type IIb SN 2008ax: spectral and light curve evolution.
    Pastorello A., Kasliwal M.M., Crockett R.M., Valenti S., Arbour R.,
    Itagaki K., Kaspi S., Gal-Yam A., Smartt S.J., Griffith R., Maguire K.,
    Ofek E.O., Seymour N., Stern D., Wiethoff W.
   <Mon. Not. R. Astron. Soc., 389, 955-966 (2008)>
   =2008MNRAS.389..955P
ADC_Keywords: Supernovae ; Photometry, UBV ; Photometry, SDSS

Keywords: supernovae: general - supernovae: individual: SN 2008ax -
          supernovae: individual: SN 1993J - galaxies: individual: NGC 4490

Abstract:
    We present spectroscopy and photometry of the He-rich supernova (SN)
    2008ax. The early-time spectra show prominent P-Cygni H lines, which
    decrease with time and disappear completely about 2 months after the
    explosion. In the same period HeI lines become the most prominent
    spectral features. SN 2008ax displays the ordinary spectral evolution
    of a Type IIb supernova. A stringent pre-discovery limit constrains
    the time of the shock breakout of SN 2008ax to within only a few
    hours. Its light curve, which peaks in the B band about 20d after the
    explosion, strongly resembles that of other He-rich core-collapse
    supernovae. The observed evolution of SN 2008ax is consistent with the
    explosion of a young Wolf-Rayet (of WNL type) star, which had
    retained a thin, low-mass shell of its original H envelope. The
    overall characteristics of SN 2008ax are reminiscent of those of
    SN 1993J, except for a likely smaller H mass. This may account for the
    findings that the progenitor of SN 2008ax was a WNL star and not a K
    supergiant as in the case of SN 1993J, that a prominent early-time
    peak is missing in the light curve of SN 2008ax, and that Hα is
    observed at higher velocities in SN 2008ax than in SN 1993J.

Description:
    SN 2008ax is one of the best ever monitored core-collapse SNe,
    starting with a deep pre-explosion image obtained only 6h prior to
    the SN discovery of Mostardi et al. (2008CBET.1280....1M). The
    observational campaign of SN 2008ax started soon after the discovery
    and covered a period of about 70d. Photometry has been obtained at
    the 2-m Liverpool Telescope in La Palma (Canary Islands, Spain) and
    the 60-inch Telescope of the Palomar Observatory. In addition,
    unfiltered data collected by amateur astronomers have been used in our
    analysis. These data have been scaled to the Johnson-Bessell V-band
    or the Sloan r'-band photometry, depending on the sensitivity curves
    of the CCDs used in these observations.
Objects:
    -------------------------------------------------
       RA   (2000)   DE      Designation(s)
    -------------------------------------------------
    12 30 40.8   +41 38 15   SN 2008ax = SN 2008ax
    -------------------------------------------------

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat       116       67   Optical photometry of SN 2008ax
table2.dat        52       54   Unfiltered photometry of SN 2008ax from amateur
                              astronomers, rescaled to the Johnson-Bessell V
                              and/or Sloan r' bands


Byte-by-byte Description of file: table1.dat

   Bytes Format Units      Label     Explanations

   1- 10  A10 "YYYY/MM/DD" Date      Observation date
  12- 21  F10.2 d          JD        Julian date
  23- 28  F6.3  mag        u'mag     ? SDSS u' magnitude
  30- 34  F5.3  mag        e_u'mag   ? rms uncertainty on u'mag
  36- 41  F6.3  mag        Bmag      ? Johnson B magnitude
  43- 47  F5.3  mag        e_Bmag    ? rms uncertainty on Bmag
  49- 54  F6.3  mag        Vmag      ? Johnson V magnitude
  56- 60  F5.3  mag        e_Vmag    ? rms uncertainty on Vmag
  62- 67  F6.3  mag        g'mag     ? SDSS g' magnitude
  69- 73  F5.3  mag        e_g'mag   ? rms uncertainty on g'mag
  75- 80  F6.3  mag        r'mag     ? SDSS r' magnitude
  82- 86  F5.3  mag        e_r'mag   ? rms uncertainty on r'mag
  88- 93  F6.3  mag        i'mag     ? SDSS i' magnitude
  95- 99  F5.3  mag        e_i'mag   ? rms uncertainty on i'mag
 101-106  F6.3  mag        z'mag     ? SDSS z' magnitude
 108-112  F5.3  mag        e_z'mag   ? rms uncertainty on z'mag
 114-116  A3    ---        Inst      Instrument (1)

Note (1): Instrument code as follows:
    LT  = 2-m Liverpool Telescope + RatCAM
    P60 = Robotic Palomar 60-inch Telescope + CCD


Byte-by-byte Description of file: table2.dat

   Bytes Format Units      Label     Explanations

   1- 10  A10 "YYYY/MM/DD" Date      Observation date
  12- 21  F10.2 d          JD        Julian date
      23  A1    ---        l_CVmag   limit flag on CVmag
  24- 29  F6.3  mag        CVmag     ? Rescaled Johnson V magnitude
  31- 35  F5.3  mag        e_CVmag   ? rms uncertainty on CVmag
      37  A1    ---        l_Cr'mag  limit flag on Cr'mag
  38- 43  F6.3  mag        Cr'mag    ? Rescaled SDSS r' magnitude
  45- 49  F5.3  mag        e_Cr'mag  ? rms uncertainty on Cr'mag
  51- 52  A2    ---        Inst      Instrument and observer (1)

Note (1): Instrument code as follows:
     RA = 40cm f/5 Newtonian + SXV-H9 CCD (R. Arbour, UK)
     WW = 35cm C14 OTA + DSI Pro II w/Sony EXview HAD CCD (ICX 429)
          (W. Wiethoff, US)
     KI = 60cm f/5.7 + Bitran BT-214E CCD (Kodak KAF-1001E)
          (K. Itagaki, Japan)


History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    01-Feb-2010