Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ludendorff Coronal Flattening Index of the Total Solar Eclipse on March
  9, 2016   Ludendorff coronal flattening index of the Total Solar Eclipse (TSE) on March
9, 2016, was calculated at various distances in solar radius. As a result, we
obtained the coronal flattening index $\left(\epsilon =a+b\right)$ at a
distance of 2 solar radii is 0.16. The $24^{th}$ solar cycle phase based on the
2016 TSE event obtained -0.64 which showed the corona is pre-minimum type.
Resulted coronal flattening index value gives a predicted maximum amplitude of
the monthly sunspot number ($W_{max}$) for the $25^{th}$ solar cycle to be
$70\pm65$. Therefore, the solar activity for $25^{th}$ solar cycle predicted to
be lower than the current solar cycle, which has a maximum sunspot number value
of 146 in February 2014

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The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-ex