  Local Group (LG), the nearest and most complete galactic environment,
provides valuable information on the formation and evolution of the Universe.
Studying galaxies of different sizes, morphologies, and ages can provide this
information. For this purpose, we chose the And\,IX dSph galaxy, which is one
of the observational targets of the Isaac Newton Telescope (INT) survey. A
total of 50 long-period variables (LPVs) were found in And\,IX in two filters,
Sloan $i'$ and Harris $V$ at a half-light radius of 2.5 arcmin. The And\,IX's
star formation history (SFH) was constructed with a maximum star formation rate
(SFR) of about $0.00082\pm0.00031$ M$_\odot$ yr$^{-1}$, using LPVs as a tracer.
The total mass return rate of LPVs was calculated based on the spectral energy
distribution (SED) of about $2.4\times10^{-4}$ M$_\odot$ yr$^{-1}$. The
distance modulus of $24.56_{-0.15}^{+0.05}$ mag was estimated based on the tip
of the red giant branch (TRGB).
