  An interesting asteroseismic target is the G9.5 IV solar-like star beta Aql.
This is an ideal target for asteroseismic investigations, because precise
astrometric measurements are available from Hipparcos that greatly help in
constraining the theoretical interpretation of the results. The star was
observed during six nights in August 2009 by means of the high-resolution
\'echelle spectrograph SARG operating with the TNG 3.58 m Italian telescope on
the Canary Islands, exploiting the iodine cell technique. We present the result
and the detailed analysis of high-precision radial velocity measurements, where
the possibility of detecting time individual p-mode frequencies for the first
and deriving their corresponding asymptotic values will be discussed. The
time-series analysis carried out from \sim 800 collected spectra shows the
typical p-mode frequency pattern with a maximum centered at 416 \muHz. In the
frequency range 300 - 600 \muHz we identified for the first time six high S/N
(\gtrsim 3.5) modes with l = 0,2 and 11 < n < 16 and three possible candidates
for mixed modes (l = 1), although the p-mode identification for this type of
star appears to be quite difficult owing to a substantial presence of avoided
crossings. The large frequency separation and the surface term from the set of
identified modes by means of the asymptotic relation were derived for the first
time. Their values are \Delta \nu = 29.56 \pm 0.10 \muHz and \epsilon = 1.29
\pm 0.04, consistent with expectations. The most likely value for the small
separation is \delta\nu_{02} = 2.55 \pm 0.71 \muHz.
