2691 Sérsic

2691 Sérsic (provisional designation 1974 KB) is a stony asteroid from the inner main belt, belonging to the Flora family. It is also a binary system, with a diameter of roughly 6 kilometers. The object was discovered on 18 May 1974 by staff of the Felix Aguilar Observatory at the El Leoncito Complex in Argentina. It was later named for Argentine astronomer José Luis Sérsic.

As a member of the Flora family—one of the largest groups of stony asteroids in the main belt—Sérsic orbits the Sun at a distance between 2.0 and 2.5 AU. Its orbit takes about 3 years and 4 months (1,228 days) to complete, with an eccentricity of 0.11 and an inclination of 4° relative to the ecliptic.

The asteroid’s diameter is estimated at 6.21 kilometers, based on an assumed albedo of 0.24 (derived from 8 Flora, the family’s largest member) and an absolute magnitude of 13.2. This calculation comes from the Collaborative Asteroid Lightcurve Link.

In 2011, lightcurve observations revealed that Sérsic has a small moon. The satellite is about 2.15 ± 0.11 kilometers in diameter and orbits the primary once every 1 day, 2 hours, and 48 minutes.

The minor planet was named for José Luis Sérsic (1933–1993), known for his work in extragalactic astronomy and supernovae, and for serving as director of the Córdoba Observatory. The naming citation was published by the Minor Planet Center on 20 February 1989 (M.P.C. 14207).