Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Astrometry of circumstellar masers   The circumstellar masers around evolved stars offer an interesting
possibility to measure stellar parameters through VLBI astrometry. In this
paper the application of this technique is discussed, including the accuracy
and the uncertainties of the method. The different maser species (OH, H_2O,
SiO) have slightly different characteristics and applications. This paper does
not concern astrometry of maser spots to study the kinematics of the envelope,
but concentrates on attempting to measure the motion of the underlying star.

24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin