702 Alauda , provisional designation , is a carbonaceous

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

and

binary system A binary system is a system of two astronomical bodies of the same kind that are comparable in size. Definitions vary, but typically require the center of mass to be located outside of either object. (See animated examples.) The most common ki ...

from the outer

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

, approximately 190 kilometers in diameter. It is the

parent body A parent body in meteoritics is the celestial body from which originates a meteorite or a class of meteorites. Identification It is easiest to correlate a meteorite with a parent body when the parent body still exists. This is the case for Lun ...

of the Alauda family. Discovered in 1910 by German astronomer

Joseph Helffrich Joseph Helffrich (12 January 1890 in Mannheim, Baden – 1971) was a German astronomer. He did his Ph.D. dissertation in 1913 at the ''Landessternwarte Heidelberg-Königstuhl'' (Königstuhl Observatory, near Heidelberg) at the University of ...

Heidelberg Observatory Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

, it was named after the

lark Larks are passerine birds of the family Alaudidae. Larks have a cosmopolitan distribution with the largest number of species occurring in Africa. Only a single species, the horned lark, occurs in North America, and only Horsfield's bush lark occ ...

(''alauda''). Its small

moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

, named Pichi üñëm, was discovered in 2007.

Satellite

Alauda's satellite Pichi üñëm, provisionally known as , was discovered on 26 July 2007 from observations using adaptive-optics imaging with the

European Southern Observatory The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 m ...

(ESO) 8-m

Very Large Telescope The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with ...

(VLT) on Cerro Paranal, Chile. It is about 3.5 km in diameter (assuming it has the same

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

as the primary) and orbits Alauda in a nearly circular orbit at a distance of . Pichi üñëm takes 4.91 days to complete one orbit. It was named ''Pichi üñëm'' (, approximately ), meaning "little bird" in the

Mapuche language Mapuche ( , ; from 'land' and 'people', meaning 'the people of the land') or Mapudungun (from 'land' and 'speak, speech', meaning 'the speech of the land'; also spelled Mapuzugun and Mapudungu) is either a language isolate or member of the sm ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, the country from which the moon was discovered.

Orbital characteristics

Alauda has been identified as the largest member of the Alauda family, a dynamical family of bright carbonaceous asteroids with more than a thousand known members. Other members of this family include: 581 Tauntonia, 1101 Clematis, 1838 Ursa, 3139 Shantou, 3325 TARDIS, 4368 Pillmore, 5360 Rozhdestvenskij, 5815 Shinsengumi, and many others. Alauda's moon may be a result of the collision that created the

asteroid family An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An ...

Physical characteristics

The discovery and tracking of Alauda's moon enabled Alauda's

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

to be determined. The discoverers of the moon, Patricio Rojo and

Jean-Luc Margot Jean-Luc Margot (born 1969) is a Belgian-born astronomer and a UCLA professor with expertise in planetary sciences and SETI. Career Margot has discovered and studied several binary asteroids with radar and optical telescopes. His discoveries ...

, estimated Alauda's mass to be and its density to be .

Occultations

Alauda has been observed to

occult The occult () is a category of esoteric or supernatural beliefs and practices which generally fall outside the scope of organized religion and science, encompassing phenomena involving a 'hidden' or 'secret' agency, such as magic and mysti ...

stars on several occasions, providing important information on its size and shape. It produced occultations on 2001-07-12 and 2004-04-21. It may have occulted an

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

9.5 star in the constellation of

Gemini Gemini most often refers to: * Gemini (constellation), one of the constellations of the zodiac * Gemini (astrology), an astrological sign Gemini may also refer to: Science and technology Space * Gemini in Chinese astronomy, the Gemini constellat ...

on 2009-10-17 at 08:18 UT. This event should have been visible from Uruguay, Argentina, and Chile.

References

External links

Asteroids with Satellites
Robert Johnston, johnstonsarchive.net * * {{DEFAULTSORT:Alauda 000702 Discoveries by Joseph Helffrich Named minor planets 000702 000702 000702 000702 19100716