STF 2398 (Gliese 725) is a binary system located 11.65 light-years from the Sun. The primary component, A, is a red dwarf of spectral class M4V with a mass of 0.33 and a diameter of 0.35 solar masses. The companion, B, is another red dwarf of spectral class M4.5V with a mass of 0.25 and a diameter of 0.27 solar masses. They orbit their common center of mass in 408 years. In 2016, two exoplanets were discovered around component B. The first, with a mass of 15 Earths, orbits at a distance of 0.261 AU from the host star with an orbital period of approximately 91 days. The second, with a mass of 13 Earths, orbits at a distance of 0.428 AU with an orbital period of around 192 days. The confirmation of these exoplanet discoveries is still pending.

100mm - STF 2398 is located approximately 1°NNE of the star Omicron Draconis. Due to its proximity of just under 12 light-years, it can be well observed even with small telescopes. The components can be resolved at moderate magnifications, and despite their relatively low brightness, there is a noticeable orange tint for the primary component and a red tint for the companion.