Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Nature of Solar Polar Rays   We use time series observations from the SOHO and Yohkoh spacecraft to study
solar polar rays. Contrary to our expectations, we find that the rays are
associated with active regions on the sun and are not features of the polar
coronal holes. They are extended, hot plasma structures formed in the active
regions and projected onto the plane of the sky above the polar coronal holes.
We present new observations and simple projection models that match long-lived
polar ray structures seen in limb synoptic maps. Individual projection patterns
last for at least 5 solar rotations.

30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics