J/MNRAS/410/585     SN 2009dc BVRI light curves              (Silverman+, 2011)
Fourteen months of observations of the possible super-Chandrasekhar mass type Ia
supernova 2009dc.
    Silverman J.M., Ganeshalingam M., Li W., Filippenko A.V., Miller A.A.,
    Poznanski D.
   <Mon. Not. R. Astron. Soc., 410, 585-611 (2011)>
   =2011MNRAS.410..585S 2011MNRAS.410..585S
ADC_Keywords: Supernovae ; Photometry
Keywords: supernovae: general - supernovae: individual: SN 2009dc -
          supernovae: individual: SN 2007if -
          supernovae: individual: SN 2003fg - supernovae: individual: SN 2006gz
Abstract:
    In this paper, we present and analyse optical photometry and spectra
    of the extremely luminous and slowly evolving Type Ia supernova (SN
    Ia) 2009dc, and offer evidence that it is a super-Chandrasekhar mass
    (SC) SN Ia and thus has a SC white dwarf (WD) progenitor. Optical
    spectra of SN 2007if, a similar object, are also shown. SN 2009dc had
    one of the most slowly evolving light curves ever observed for a SN
    Ia, with a rise time of ∼23d and {DELTA}m15(B)=0.72mag. We calculate
    a lower limit to the peak bolometric luminosity of ∼2.4x1043erg/s,
    though the actual value is likely almost 40 per cent larger. Optical
    spectra of SN 2009dc and SN 2007if obtained near maximum brightness
    exhibit strong CII features (indicative of a significant amount of
    unburned material), and the post-maximum spectra are dominated by
    iron-group elements (IGEs). All of our spectra of SN 2009dc and SN
    2007if also show low expansion velocities. However, we see no strong
    evidence in SN 2009dc for a velocity `plateau' near maximum light like
    the one seen in SN 2007if. The high luminosity and low expansion
    velocities of SN 2009dc lead us to derive a possible WD progenitor
    mass of more than 2M☉ and a 56Ni mass of about 1.4-1.7M☉.
Description:
    Observations of SN 2009dc began on 2009 Apr. 17, about one week before
    maximum B-band brightness, in BVRI filters using the 0.76-m Katzman
    Automatic Imaging Telescope (KAIT) and the 1-m Nickel telescope, both
    at Lick Observatory. We continued to follow SN 2009dc for over 5
    months until 2009 Sept. 26, when it reached the western limit of both
    telescopes in the early evening. We obtained late-time gVRI images of
    SN 2009dc using the dual-arm Low-Resolution Imaging Spectrometer
    (LRIS) with the 10-m Keck I telescope on 2010 Feb. 6 (281d past
    maximum), BRI images using the DEIMOS spectrograph (Faber et al. 2003)
    mounted on the 10-m Keck II telescope on 2010 Jun. 12 (403d past
    maximum) and V-band images again using LRIS on 2010 Jun. 13.
    Our optical photometry is complemented with data taken from the
    UltraViolet Optical Telescope (UVOT) on the Swift Observatory in the
    U, B, V, UVW1, UVM2 and UVW2 filters. We downloaded seven epochs of
    observations from the Swift archives.
Objects:
    ----------------------------------------------
       RA   (2000)   DE      Designation(s)
    ----------------------------------------------
    15 51 12.1   +25 42 28   SN 2009dc = SN 2009dc
    ----------------------------------------------
File Summary:
--------------------------------------------------------------------------------
 FileName   Lrecl  Records   Explanations
--------------------------------------------------------------------------------
ReadMe         80        .   This file
table2.dat     65       66   Early-time BVRI photometry of SN 2009dc
table4.dat     28       34   UVOT (aboard Swift) photometry of SN 2009dc
--------------------------------------------------------------------------------
See also:
   B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 10  F10.2 d       JD        Julian date
  12- 17  F6.3  mag     Bmag      ?=- Johnson B magnitude
  19- 22  F4.3  mag   e_Bmag      ?=- rms uncertainty on Bmag
  24- 29  F6.3  mag     Vmag      ?=- Johnson V magnitude
  31- 34  F4.3  mag   e_Vmag      ?=- rms uncertainty on Vmag
  36- 41  F6.3  mag     Rcmag     ?=- Cousins R magnitude
  43- 46  F4.3  mag   e_Rcmag     ?=- rms uncertainty on Rcmag
  48- 53  F6.3  mag     Icmag     ?=- Cousins I magnitude
  55- 58  F4.3  mag   e_Icmag     ?=- rms uncertainty on Icmag
  60- 65  A6    ---     Tel       Telescope used
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 10  F10.2 d       JD        Julian date
  12- 15  A4    ---     Filt      [UVM2 UVW1 UVW2 UBV] Filter (1)
  17- 22  F6.3  mag     mag       Magnitude in Filter
  24- 28  F5.3  mag   e_mag       rms uncertainty on mag
--------------------------------------------------------------------------------
Note (1): UBV in Johnson-Cousins system; the UV filters central wavelength
  (c) and FWHM (w) are, in nm (see Poole et al. 2008MNRAS.383..627P 2008MNRAS.383..627P):
      -----------------
       (F)   (c)   (w)
      -----------------
      UVW1  260.0  69.3
      UVM2  224.6  49.8
      UVW2  192.8  65.7 
      -----------------
--------------------------------------------------------------------------------
History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    14-Aug-2011