(335) Roberta ( lat. Roberta ) - an asteroid on the outer part of the main belt , which belongs to the rare spectral class B. It was discovered on September 1, 1892 by the German astronomer Max Wolf at the Heidelberg Observatory and named after the Russian entomologist and diplomat Robert Osten-Sacken , who described a number of zoological taxa [1] .
| (335) Roberta | |
|---|---|
| Asteroid | |
| Opening | |
| Discoverer | Anton Staus |
| Place of discovery | Heidelberg |
| Discovery date | September 1, 1892 |
| Eponym | R. R. Osten-Saken |
| Alternative notation | 1892 C ; 1956 EB 1 ; 1973 KE; A910 EC |
| Category | Main ring |
| Orbital characteristics | |
| Age of March 14, 2012 JD 2456000.5 | |
| Eccentricity ( e ) | 0.1738079 |
| Semimajor axis ( a ) | 370.262 million km (2.4750507 A.E.) |
| Perihelion ( q ) | 305.908 million km (2.0448673 AU) |
| Aphelion ( Q ) | 434.617 million km (2,9052341 AU) |
| Circulation Period ( P ) | 1422.246 days (3.894 g. ) |
| Average orbital speed | 18.788 km / s |
| Inclination ( i ) | 5,09425 ° |
| Longitude node (Ω) | 148.51199 ° |
| Perihelion Argument (ω) | 139.31481 ° |
| Median Anomaly ( M ) | 311,30762 ° |
| physical characteristics | |
| Diameter | 89.07 km |
| Weight | 7.4⋅10 17 kg |
| Density | 2,000 g / cm³ |
| Acceleration of free fall on the surface | 0.0249 m / s² |
| 2nd space speed | 0.0471 km / s |
| Rotation period | 12,054 h |
| Spectral class | B |
| Apparent magnitude | 13.81 m (current) |
| Absolute magnitude | 8.96 m |
| Albedo | 0,0580 |
| Average surface temperature | 179 K (−94 ° C ) |
| Current distance from the sun | 2.403 a. e. |
| Current distance from earth | 3,395 a e. |
In the classical classification, Tolen occupies an intermediate position between B- and F-classes, with some characteristics of the P-class. The presence of magnetite (Fe 3 O 4 ) was observed in the spectrum of this asteroid, which gives the spectrum a bluish tint, which is characteristic of this SMASS class. The spectrum also contains absorption lines at a wavelength of 2.9 μm, which indicates the presence of hydrated minerals, which indicates changes in the chemical composition of rocks that occurred on the asteroid during its existence [2] .
See also
- The list of asteroids ( 301-400 )
- Classifications of Minor Planets
Notes
- ↑ Schmadel, Lutz D. Dictionary of Minor Planet Names . - Fifth Revised and Enlarged Edition. - B. , Heidelberg, N. Y .: Springer, 2003 .-- P. 43. - ISBN 3-540-00238-3 .
- ↑ Yang, Bin & Jewitt, David (2010), " Identification of Magnetite in B-type Asteroids ", The Astronomical Journal T. 140 (3): 692–698 , DOI 10.1088 / 0004-6256 / 140/3/692