Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The first year of SN 2004dj in NGC 2403   New BVRI photometry and optical spectroscopy of the Type IIp supernova 2004dj
in NGC 2403, obtained during the first year since discovery, are presented. The
progenitor cluster, Sandage 96, is also detected on pre-explosion frames. The
light curve indicates that the explosion occured about 30 days before
discovery, and the plateau phase lasted about +110 \pm 20 days after that. The
plateau-phase spectra have been modelled with the SYNOW spectral synthesis code
using H, NaI, TiII, ScII, FeII and BaII lines. The SN distance is inferred from
the Expanding Photosphere Method and the Standard Candle Method applicable for
SNe IIp. They resulted in distances that are consistent with each other as well
as earlier Cepheid- and Tully-Fisher distances. The average distance, D = 3.47
\pm 0.29 Mpc is proposed for SN 2004dj and NGC 2403. The nickel mass produced
by the explosion is estimated as 0.02 \pm 0.01 M_o. The SED of the progenitor
cluster is reanalysed by fitting population synthesis models to our observed
BVRI data supplemented by U and JKH magnitudes from the literature. The
chi^2-minimization revealed a possible "young" solution with cluster age T_{cl}
= 8 Myr, and an "old" solution with T_{cl} = 20 - 30 Myr. The "young" solution
would imply a progenitor mass M > 20 M_o, which is higher than the previously
detected progenitor masses for Type II SNe.

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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: math
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The categories of this paper are: cs