Determining the seismic age of the young open cluster $\alpha$ Per using
  $\delta$ Scuti stars
  In this work we aim at constraining the age of the young open cluster Melotte
20, known as $\alpha$ Per, using seismic indices. The method consists of the
following steps: 1) Extract the frequency content of a sample of stars in the
field of an open cluster. 2) Search for possible regularities in the frequency
spectra of $\delta$ Scuti candidates, using different techniques, such as the
Fourier transform, the autocorrelation function, the histogram of frequency
differences and the \'echelle diagram. 3) Constrain the age of the selected
stars by both the physical parameters and seismic indices by comparing them
with a grid of asteroseismic models representative of $\delta$ Scuti stars. 4)
Find possible common ages between these stars to determine the age of the
cluster. We performed the pulsation analysis with MultiModes, a rapid, accurate
and powerful open-source code, which is presented in this paper. The result is
that the age of $\alpha$ Per could be between 96 and 100 Myr. This is an
improvement over different techniques in the past. We therefore show that space
astroseismology is capable of taking important steps in the dating of young
open clusters.
