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 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 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)
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12 30 40.8 +41 38 15 SN 2008ax = SN 2008ax
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File Summary:
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FileName Lrecl Records Explanations
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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
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Byte-by-byte Description of file: table1.dat
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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)
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Note (1): Instrument code as follows:
LT = 2-m Liverpool Telescope + RatCAM
P60 = Robotic Palomar 60-inch Telescope + CCD
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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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)
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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)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 01-Feb-2010