702 Alauda , provisional designation , is a carbonaceous
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
and
binary system
A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter ''(also see animated examples)''. More restrictive definitions require that thi ...
from the outer
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
, approximately 190 kilometers in diameter.
[ It is the ]parent body
In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites.
Identification
The easiest way to correlate a meteorite with a parent body is when the parent body still exists. This is the case fo ...
of the Alauda family. Discovered in 1910 by German astronomer Joseph Helffrich at Heidelberg Observatory
Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students.
...
, 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 occu ...
(''alauda''). Its small moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
, 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 mem ...
(ESO) 8-m Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m across, ...
(VLT) on Cerro Paranal, Chile. It is about 3.5 km in diameter (assuming it has the same albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
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'' (Mapuche pronunciation: , approximately ), meaning "little bird" in the Mapuche language
Mapuche (, Mapuche & Spanish: , or Mapudungun; from ' 'land' and ' 'speak, speech') is an Araucanian language related to Huilliche spoken in south-central Chile and west-central Argentina by the Mapuche people (from ''mapu'' 'land' and ''che ...
of Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
, 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 a ...
.
Physical characteristics
The discovery and tracking of Alauda's moon enabled Alauda's mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...
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 who specializes in planetary sciences.
Career
Margot has discovered and studied several binary asteroids with radar and optical telescopes. His discoveries include ( ...
, estimated Alauda's mass to be (6.057 ± 0.36) kg and its density to be (1.57 ± 0.5) g/cm3.
Occultations
Alauda has been observed to occult
The occult, in the broadest sense, is a category of esoteric supernatural beliefs and practices which generally fall outside the scope of religion and science, encompassing phenomena involving otherworldly agency, such as magic and mysticism a ...
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 brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...
9.5 star in the constellation of Gemini
Gemini may refer to:
Space
* Gemini (constellation), one of the constellations of the zodiac
** Gemini in Chinese astronomy
* Project Gemini, the second U.S. crewed spaceflight program
* Gemini Observatory, consisting of telescopes in the Northern ...
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
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Discoveries by Joseph Helffrich
Named minor planets
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