(90) Antiope ( Latin Antiope ) is a double asteroid of the main belt , which belongs to the dark spectral class C. It was discovered on October 1, 1866 by the German astronomer Robert Luther [6] at the Düsseldorf Observatory and named after the character of ancient Greek mythology , but whose name is assigned to him is not known, since it has a double meaning in the mythology of the ancient Greeks: the asteroid could be named the honor of Antiope from Boeotia (according to various sources - the daughter of Niktei or Asop ), or in honor of the Antiope Amazonian - daughter of Ares [7] .
| (90) Antiope | |
|---|---|
| Asteroid | |
 Figure of the dual system of the asteroid Antiope | |
| Opening | |
| Discoverer | Robert Luther |
| Place of discovery | Dusseldorf |
| Discovery date | October 1, 1866 |
| Eponym | Antiope |
| Alternative notation | 1952 BK 2 |
| Category | Main ring ( Themis family ) |
| Orbital characteristics | |
| Age of March 14, 2012 JD 2456000.5 | |
| Eccentricity ( e ) | 0.1571135 |
| Semimajor axis ( a ) | 472.236 million km (3.1567002 AU ) |
| Perihelion ( q ) | 398.041 million km (2,66074 AU) |
| Aphelion ( Q ) | 546.43 million km (3.6526604 AU) |
| Circulation Period ( P ) | 2048.559 days (5.609 g. ) |
| Average orbital speed | 16.66 km / s |
| Inclination ( i ) | 2.21956 ° |
| Longitude node (Ω) | 70.21140 ° |
| Perihelion Argument (ω) | 243.26305 ° |
| Median Anomaly ( M ) | 49.38956 ° |
| Asteroid satellite | S / 2000 (90) 1 |
| physical characteristics | |
| Diameter | 87.8 km (93 × 87 × 83.6 km) [1] |
| Weight | 8.28⋅10 17 kg [1] [2] |
| Density | 1,250 ± 0,050 g / cm³ [2] [3] |
| Acceleration of free fall on the surface | 0.03 - 0.04 m / s² |
| 2nd space speed | 0.035 - 0.040 km / s |
| Rotation period | 16,509 h [2] |
| Spectral class | C [5] |
| Apparent magnitude | 14.92 m (current) |
| Absolute magnitude | 8.27 m |
| Albedo | 0,0603 [4] |
| Average surface temperature | 158 K (−115 ° C ) |
| Current distance from the sun | 3.648 a. e. |
| Current distance from earth | 4.44 a. e. |
Content
Double Asteroid
Opening the second component
Until 2000, Antiope was considered a single asteroid, with a diameter of about 120 km [8] . On August 10, 2000, a group of astronomers working at the Kek Observatory in Hawaii, using adaptive optics , discovered the second component, which is currently labeled S / 2000 (90) 1 [9] .
Asteroids with satellites have been discovered before, however, in previous cases, the size of the satellite was much smaller than the main component. The diameter of the satellite of Antioope turned out to be comparable with the diameter of the asteroid, therefore Antiope is considered the first [7] [8] discovered double asteroid.
It is curious that as early as 1997, an analysis of the anti-light curve of Antiope showed a classical eclipsing-binary form, which should be expected from two components of the same size observed from the edge of the orbit , although the authors of the work did not provide such an interpretation [10] .
Orbital system characteristics
System components revolve around a common center of mass at a distance of 171 ± 1 km [1] . An analysis of the light curve performed in 2001 shows that the rotational periods of both bodies coincide with the period of revolution, which is characteristic of synchronous rotation [11] . The plane of rotation of the system is tilted by 63.7 ° relative to the plane of the ecliptic of the solar system [1] .
System Physical Characteristics
Asteroid belongs to the family of Themis . Like most asteroids of this family, Antiope (and probably her companion) has a dark, carbon surface , and is classified as a class C asteroid . A low system density indicates significant porosity (more than 30%). This suggests that Antiope formed from the wreckage of earlier collisions of asteroids or other celestial bodies . Another hypothesis suggests that both components of the system are fragments of one parent body, destroyed due to a collision with an external celestial body at a very high speed [8] .
The components of the system have similar dimensions: the average diameter of Antiope is 87.8 km, its satellite - 83.8 km [1] . Studies of the features of the asteroid light curve conducted by Russian scientists at the Pulkovo Observatory and the Institute of Solar-Terrestrial Physics in Irkutsk indicate a strong dependence of the light on the phase angle, which can indicate a very flattened shape of the components [12] .
See also
- List of asteroids ( 1-100 )
- Classifications of Minor Planets
Notes
- ↑ 1 2 3 4 5 Asteroids with Satellites by Wm. Robert Johnston Date of treatment September 21, 2009. Archived March 19, 2012.
- ↑ 1 2 3 General data of the system (both components)
- ↑ Descamps, P. et al. Figure of the double Asteroid 90 Antiope from adaptive optics and lightcurve observations // Icarus: journal. - 2007. - Vol. 187 . - P. 482-499 . (eng.)
- ↑ Supplemental IRAS Minor Planet Survey
- ↑ PDS spectral class data
- ↑ Antiope, planet // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
- ↑ 1 2 Schmadel, Lutz D. Dictionary of Minor Planet Names . - Fifth Revised and Enlarged Edition. - B. , Heidelberg, N. Y .: Springer, 2003 .-- P. 23. - ISBN 3-540-00238-3 .
- ↑ 1 2 3 Asteroids Do Have Satellites . - 2002. - P. 289-312. (eng.)
- ↑ IAUC 7503: 2000dp; Sats OF MINOR PLANETS ( inaccessible link - history ) . Date of appeal September 21, 2009.
- ↑ Hansen, AT; Arentoft, T .; Lang, K. The Rotational Period of 90 Antiope (unknown) // The Minor Planet Bulletin. - 1997 .-- T. 24 . - S. 17 . (eng.)
- ↑ IAUC 7757: (90); 1987A (English) (unreachable link - history ) . Date of appeal September 21, 2009.
- ↑ I. A. Vereshchagin, D. L. Gorshanov, A. V. Devyatkin, P. G. Papushev. Some features of the light curves of asteroids (39) Letizia, (87) Sylvia, (90) Antiope, and 2006 VV 2 (Russian) // Astronomical Bulletin: Journal. - 2009 .-- T. 43 . - S. 305-314 . (inaccessible link)