It is categorized as an S-type asteroid consisting of mainly of iron- and magnesium-silicates. This the second most common type of asteroid in the main belt. Based on analysis of the light curve, the object has a sidereal rotation period of 0.513202 ± 0.000002 days. An ellipsoidalmodel of the light curve gives an /b ratio of 1.28 ± 0.05.
With a semimajor axis of 2.628, the asteroid is orbiting between the 3:1 and 5:2 Kirkwood gaps in the main belt. Its orbital eccentricity is larger than the median value of 0.07 for the main belt, and the inclination is larger than the median of below 4°. But most of the main-belt asteroids have an eccentricity of no more than 0.4 and an inclination of up to 30°, so the orbit of 23 Thalia is not unusual for a main-belt asteroid.
^Schmadel, Lutz D. (2003). Dictionary of minor planet names (5th ed.). Springer. p. 17. ISBN3-540-00238-3.
^Lagerkvist, C.-I.; et al. (October 1995). "Physical studies of asteroids. XXIX. Photometry and analysis of 27 asteroids". Astronomy and Astrophysics Supplement113: 115–122. Bibcode:1995A&AS..113..115L.