Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of magnetic fields in central stars of planetary nebulae   For the first time we have directly detected magnetic fields in central stars
of planetary nebulae by means of spectro-polarimetry with FORS1 at the VLT. In
all four objects of our sample we found kilogauss magnetic fields, in NGC1360
and LSS1362 with very high significance, while in EGB5 and Abell36 the
existence of a magnetic field is probable but with less certainty. This
discovery supports the hypothesis that the non-spherical symmetry of most
planetary nebulae is caused by magnetic fields in AGB stars. Our high discovery
rate demands mechanisms to prevent full conservation of magnetic flux during
the transition to white dwarfs.

8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
2
The categories of this paper are: math
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org