Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simultaneous Optical and X-ray Observations of Flares and Rotational
  Modulation on the RS CVn Binary HR 1099 (V711 Tau) from the MUSICOS 1998
  Campaign   We present simultaneous and continuous observations of the H$\alpha$,
H$\beta$, He {\sc i} D$_{3}$, Na {\sc i} D$_{1}$,D$_{2}$ doublet and the Ca
{\sc ii} H & K lines for the RS CVn system HR 1099. The spectroscopic
observations were obtained during the MUSICOS 1998 campaign involving several
observatories and instruments, both echelle and long-slit spectrographs. During
this campaign, HR 1099 was observed almost continuously for more than 8 orbits
of $2\fd8$. Two large optical flares were observed, both showing an increase in
the emission of H$\alpha$, Ca {\sc ii} H & K, H$\beta$ and He {\sc i} D$_{3}$
and a strong filling-in of the Na {\sc i} D$_{1}$,D$_{2}$ doublet.
{Contemporary photometric observations were carried out with the robotic
telescopes APT-80 of Catania and Phoenix-25 of Fairborn Observatories. Maps of
the distribution of the spotted regions on the photosphere of the binary
components were derived using the Maximum Entropy and Tikhonov photometric
regularization criteria}. Rotational modulation was observed in H$\alpha$ and
He {\sc i} D$_{3}$ in anti-correlation with the photometric light curves. Both
flares occurred at the same binary phase (0.85), suggesting that these events
took place in the same active region. Simultaneous X-ray observations,
performed by ASM on board RXTE, show several flare-like events, some of which
correlate well with the observed optical flares. Rotational modulation in the
X-ray light curve has been detected with minimum flux when the less active G5 V
star was in front. A possible periodicity in the X-ray flare-like events was
also found.

0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat