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1 Introduction

Be stars are rapid rotating, early type stars characterised by Balmer line emission and IR excess. They exhibit irregular variability both, spectroscopically and photometrically. They are surrounded by a gaseous envelope, which is photoionized by the radiation from the central star. The subsequent recombination process gives rise to the hydrogen line emission. The emission line profiles of Be stars show a variety of shapes. One of the earliest models to explain these profiles was the rotational model by Struve (1931). Since then many emission line spectroscopic studies have been made to understand the Be phenomenon - particularly the process of envelope formation - and the physical parameters of the disk like its shape, size and kinematics.

Though great progress has been made in explaining the line profiles, by invoking general physical mechanisms, there are still certain aspects which are not well understood. Hummel & Dachs (1992) and Hummel (1994) have proposed an elegant mechanism which largely explains as to how symmetric profiles of the winebottle through the shell type, and their variations in between, can be generated by the same optically thick Keplerian envelope when viewed from different angles. One of the objectives of the present study is to see how observational data agree with the scenario put forward by Hummel (1994). Towards this end, we have acquired high resolution H$\alpha$ profiles for a sample of 44 Be stars. Given the latitude of our observatory (24.653 $^\circ$N), both, the northern and the mid-southern declination sources are accessible in the sky, and this is reflected in the choice of our sources.

The other objective behind this study was the idea of building up, or filling in the gaps in, the database of the emission line profiles of Be stars, particularly that for the temporal variability of the line profiles. The atlas by Hanuschik et al. (1996) shows that significant variations can occur in the profiles over protracted periods. Our data is intended to make an additional input for any comprehensive model, that may be constructed, for explaining the variability. Incidentally, concurrent with this study and with a view to getting a more complete picture, a near IR spectroscopic survey of about 30 Be stars was also made at a medium resolution (R = 1000). Some of the preliminary results on this may be found in Ashok & Banerjee (2000).

  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f1.eps}\end{figure} Figure 1: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f2.eps} \end{figure} Figure 2: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f3.eps}\end{figure} Figure 3: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f4.eps}\end{figure} Figure 4: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f5.eps}\end{figure} Figure 5: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f6.eps}\end{figure} Figure 6: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f7.eps}\end{figure} Figure 7: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


  \begin{figure}
\par\includegraphics[width=16.5cm,clip]{h2226f8.eps} \end{figure} Figure 8: Plots of the line profiles of different Be stars. The intensity plotted on the Y axis is relative and in units of the continuum level ${I_{\rm c}}$


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