Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the evolutionary status of lambda Bootis stars using Hipparcos data   Using the Hipparcos data, absolute magnitudes and thus the evolutionary
status for the group of lambda Bootis stars were derived. The origin of this
small group of non-magnetic, chemically peculiar stars, still remains a matter
of debate. Using new evolutionary tracks, an age determination could be
provided to distinguish between the two competing theories - the
diffusion/mass-loss and the accretion.
  The results establish the members of this group as objects which are very
close to the Main Sequence. This is supported by Pre-Main Sequence evolutionary
tracks as well as by observational results. This contradicts prior conclusions
that most of these stars are in the middle of their Main Sequence lifetime. The
new results strongly support the predictions of the accretion theory.

10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess