• Source: 1313 Berna

1313 Berna, provisional designation 1933 QG, is a background asteroid and synchronous binary system from the Eunomian region in the central asteroid belt, approximately 14 kilometers (8.7 miles) in diameter. It was discovered on 24 August 1933, by Belgian astronomer Sylvain Arend at the Uccle Observatory in Belgium. The assumed S-type asteroid has a longer-than average rotation period of 25.5 hours and is likely elongated in shape. It was named for the Swiss capital of Bern. The discovery of an 11-kilometer-sized companion was announced in February 2004.




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 (502), 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. The name was proposed by Sigmund Mauderli (1876–1962), astronomer and director of the Astronomical Institute at the University of Bern, after whom 1748 Mauderli is named. He computed the definitive orbit of the body, and also insisted to rename the minor planet to its current name, after it had been originally published as "Bernia". The official naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 120).




Physical characteristics






= Lightcurve

=
A network of astronomers at several observatories including Raoul Behrend at Geneva Observatory, Switzerland, obtained the so-far best rated rotational light-curve of Berna. Light-curve analysis gave a rotation period of 25.464 hours with a brightness variation of 0.28 magnitude (U=3). In November 2007, photometric observations at Cerro Tololo, Chile, using its 0.9-meter Prompt5 telescope in combination with the Spitzer Space Telescope gave a concurring period of 25.46 hours with an amplitude of 0.5 magnitude (U=n.a.).: 40  Other light-curves were also obtained by several amateur astronomers giving a period of 6, 25.4 and 25.45 hours, respectively (U=1/2-/3-).




= Asteroid moon

=
In February 2004, a satellite orbiting the asteroid was discovered. The moon, designated S/2004 (1313) 1, measures about 11 kilometers in diameter and orbits Berna at a distance of 35 kilometer once every 25 hours and 28 minutes. Since the lightcurve is synchronized with the eclipse events, at least one body of the binary system rotates synchronously with the orbital motion. It was identified based on light-curve observations taken in February 2004 by several astronomers, including Raoul Behrend at Geneva Observatory, Stefano Sposetti, René Roy, Donald Pray, Christophe Demeautis, Daniel Matter, Alain Klotz and others. Although the IAUC was released on 23 February 2004, the announcement was already made on 12 February 2004. There are several hundreds of asteroids known to have satellites (also see Category:Binary asteroids).




= Diameter and albedo

=
According to the surveys carried out by the Japanese Akari satellite, NASA's Spitzer Space Telescope and the Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Berna measures between 13.12 and 19.96 kilometers in diameter and its surface has an albedo between 0.13 and 0.25. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the parent body of the Eunomia family – and calculates a diameter of 13.88 kilometers based on an absolute magnitude of 11.6.




Notes






References






External links


IAUC 8292
Behrend 2005, Four new binary Minor Planets
Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)–(5000) – Minor Planet Center
1313 Berna at AstDyS-2, Asteroids—Dynamic Site
Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
1313 Berna at the JPL Small-Body Database

Kata Kunci Pencarian:

• Daftar planet minor yang dinamai berdasarkan nama tempat
• 1313 Berna
• Natural satellite
• Berna (disambiguation)
• List of minor planets: 1001–2000
• Meanings of minor-planet names: 1001–2000
• Sylvain Arend
• Minor-planet moon
• 4492 Debussy
• 1089 Tama
• List of minor planets named after places