1313 Berna

1313 Berna is an asteroid found in the middle part of the asteroid belt, a region between the planets Mars and Jupiter. This asteroid is about 14 kilometers, or 8.7 miles, wide. It was discovered on August 24, 1933, by a Belgian astronomer named Sylvain Arend at the Uccle Observatory in Belgium.

This asteroid is special because it is part of a binary system, meaning it has a smaller companion, or satellite, that orbits around it. The satellite was found to be about 11 kilometers in size and was announced in February 2004. 1313 Berna is also longer than average in how long it takes to spin once on its axis, which is about 25.5 hours. It was named after Bern, the capital city of Switzerland.

Orbit and classification

According to modern HCM-analyses by Nesvorný, as well as by Milani and Knežević, Berna is a non-family asteroid from the main belt's background population.

Based on osculating Keplerian orbital elements, it is located in the region of the Eunomia family, a prominent family of stony asteroids. It orbits the Sun in the central asteroid belt at a distance of 2.1–3.2 AU once every 4 years and 4 months (1,584 days; semi-major axis of 2.66 AU). Its orbit has an eccentricity of 0.21 and an inclination of 13° with respect to the ecliptic. In 1911, Berna was first identified as A911 OA at Johannesburg. Its observation arc begins with its official discovery observation at Uccle.

Naming

This minor planet was named after the Swiss capital city of Bern. An astronomer named Sigmund Mauderli suggested this name. He worked at the University of Bern and helped figure out the asteroid's path. The official naming was mentioned in a book about minor planets in 1955.

Physical characteristics

Astronomers have studied how Berna spins and found it takes about 25.5 hours to complete one turn. They also discovered a small companion, or moon, orbiting Berna. This moon is about 11 kilometers wide and circles Berna every 25 hours and 28 minutes.

Measurements from space telescopes show that Berna is roughly between 13 and 20 kilometers in diameter. Its surface reflects only a small amount of sunlight.