  Four transits of the exoplanet HAT-P-23b were recently observed with the
0.36m telescope at the Universidad de Monterrey Observatory. The four light
curves were successfully combined to obtain a resulting one with reduced
scattering per bin. This one was modeled using a Monte Carlo method to obtain
the essential parameters that characterize the system. Assuming orbital
parameters such as eccentricity, e, and longitude of periastron, w, from the
discovery paper, we found values of Rp/R* = 0.1105 +0.0015-0.0013 for the
planet-to-star radius ratio, a/R* = 4.23 +0.06-0.12 for the scaled semimajor
axis, and an orbital inclination of the system of i = 87.9d +1.5-2.2. We also
derive an improved orbital period of 1.2128868 +- 0.0000004 days (To =
2,454,852.26542 +- 0.00018 BJD_TDB) for the system.
