Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An outburst of the magnetic cataclysmic variable XY Arietis observed
  with RXTE   We report the first observed outburst of the magnetic cataclysmic variable XY
Ari. X-ray observations show a flux increase by an order of magnitude the day
after the first signs of outburst. During the 5-d duration the X-ray spin pulse
is greatly enhanced and the X-ray spectrum far more absorbed. We suggest that
the inner disc pushes inwards during outburst, blocking the view to the lower
accreting pole, breaking the symmetry present in quiescence, and so producing a
large pulsation. The observations are consistent with a disc instability as the
cause of the outburst, although we can't rule out alternatives. We draw
parallels between our data and the UV delay and dwarf nova oscillations seen in
non-magnetic dwarf novae.

14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an