Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time-resolved spectroscopy of the peculiar Halpha variable Be star HD
  76534   We present time-resolved spectroscopy of the Be star HD 76534, which was
observed to have an Halpha outburst in 1995, when the line went from
photospheric absorption to emission at a level of more than two times the
continuum within 2.5 hours. To investigate the short-term behaviour of the
spectrum of HD 76534 we have obtained 30 spectra within two hours real-time and
searched for variations in the spectrum. Within the levels of statistical
significance, no variability was found. Rather than periodic on short time
scales, the Halpha behaviour seems to be commonly episodic on longer (>1 year)
time scales, as an assessment of the existing data on the Halpha line and the
Hipparcos photometry suggests. HD 76534 underwent only 1 photometric outburst
in the 3 year span that the star was monitored by the Hipparcos satellite.

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The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th