129 Antigone
Encyclopedia
129 Antigone is a large main-belt asteroid
. Radar observations
indicate that it is composed of almost pure nickel
-iron
. It and other similar asteroids probably originate from the core of a shattered Vesta
-like planetesimal
which had a differentiated
interior. It was discovered by C. H. F. Peters
on February 5, 1873, and named after Antigone
, the Theban princess in Greek mythology
.
In 1979 a possible satellite
of Antigone was suggested based on lightcurve data http://www.johnstonsarchive.net/astro/asteroidmoonsq.html. A model constructed from these shows Antigone itself to be quite regularly shaped http://www.astro.helsinki.fi/~kaselain/thirty.pdf.
Since 1985, a total of three stellar
occultation
s by Antigone have been observed.
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
. Radar observations
Radar astronomy
Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the echoes. This research has been conducted for six decades. Radar astronomy differs from radio astronomy in that the latter is a passive observation and the former an...
indicate that it is composed of almost pure nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
-iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. It and other similar asteroids probably originate from the core of a shattered Vesta
4 Vesta
Vesta, formally designated 4 Vesta, is one of the largest asteroids, with a mean diameter of about . It was discovered by Heinrich Wilhelm Olbers on March 29, 1807, and is named after the Roman virgin goddess of home and hearth, Vesta....
-like planetesimal
Planetesimal
Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks.A widely accepted theory of planet formation, the so-called planetesimal hypothesis of Viktor Safronov, states that planets form out of cosmic dust grains that collide and stick to form larger and larger...
which had a differentiated
Planetary differentiation
In planetary science, planetary differentiation is the process of separating out different constituents of a planetary body as a consequence of their physical or chemical behaviour, where the body develops into compositionally distinct layers; the denser materials of a planet sink to the center,...
interior. It was discovered by C. H. F. Peters
Christian Heinrich Friedrich Peters
Christian Heinrich Friedrich Peters was a German-American astronomer, and one of the first to discover asteroids....
on February 5, 1873, and named after Antigone
Antigone
In Greek mythology, Antigone is the daughter of Oedipus and Jocasta, Oedipus' mother. The name may be taken to mean "unbending", coming from "anti-" and "-gon / -gony" , but has also been suggested to mean "opposed to motherhood", "in place of a mother", or "anti-generative", based from the root...
, the Theban princess in Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
.
In 1979 a possible satellite
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
of Antigone was suggested based on lightcurve data http://www.johnstonsarchive.net/astro/asteroidmoonsq.html. A model constructed from these shows Antigone itself to be quite regularly shaped http://www.astro.helsinki.fi/~kaselain/thirty.pdf.
Since 1985, a total of three stellar
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
occultation
Occultation
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy . It can also refer to any situation wherein an object in the foreground blocks from view an object in the background...
s by Antigone have been observed.
External links
- Orbital simulation from JPL (Java)
- Ephemeris