Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: V1405 Cas Nova 2021: About the nature of a multi-maxima nova   CONTEXT: The Nova V1405 Cas, which erupted on 18 March 2021, showed a
pre-maximum phase of almost two months. After the main maximum, during several
month the nova only weakened slightly and showed clear fluctuations in
brightness. AIMS: The aim of this work is to investigate the relationship
between brightness and half-width (FWHM) and equivalent width (EW) of the
H-alpha emission line, and from this to infer possible causes for the abnormal
behavior of the Nova. METHODS: Magnitudes and spectra from online databases
were used, the H-alpha line of the spectra was measured and 2-day normal values
were formed in order to establish a temporal comparison. RESULTS: After the
main maximum, during the period investigated by JD 2459292 to 2459305 at
intervals of 2-5 weeks secondary maxima with different characteristics. The
maxima of the equivalent width were 6-14 days after the respective brightness
maxima. The maxima are interpreted as subsequent outbreaks of the nova.
Possibly these are subsequent weaker eruptions of the nova or other mechanisms
that lead to an increase in density in the envelope.

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The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom