335 Roberta
| Discovery | |
|---|---|
| Discovered by | Anton Staus |
| Discovery date | September 1, 1892 |
| Designations | |
Named after | Karl Robert Osten-Sacken |
| 1892 C | |
| Main belt | |
| Orbital characteristics[1] | |
| Epoch 30 January 2005 (JD 2453400.5) | |
| Aphelion | 434.501 Gm (2.904 AU) |
| Perihelion | 305.856 Gm (2.045 AU) |
| 370.178 Gm (2.474 AU) | |
| Eccentricity | 0.174 |
| 1,421.736 d (3.89 a) | |
Average orbital speed | 18.93 km/s |
| 12.696° | |
| Inclination | 5.093° |
| 148.541° | |
| 139.567° | |
| Physical characteristics | |
| Dimensions | 89.1 km[1] |
| 12.054 h[1] | |
| Albedo | 0.058[2] |
Spectral type | FP/B[1] |
| 8.96[1] | |
|
| |
335 Roberta is a large main belt asteroid. It was discovered by German astronomer Anton Staus on September 1, 1892 in Heidelberg.[3] This was his only asteroid discovery.
Photometric observations of this asteroid from multiple sites during 2007 gave a light curve with a period of 12.054 ± 0.003 hours and a brightness variation of 0.13 ± 0.02 in magnitude. This agrees with a result reported in 1992, but differs from period estimates of 8.03 hours and 4.349 reported in 1987 and 2001, respectively.[4]
Under the SMASS classification taxonomy, Polana is listed as a B-type asteroid; a group that combines both the Tholen B and F types. The spectrum of this object suggests the presence of magnetite (Fe3O4), which gives it the spectrally-blue coloration that is a characteristic of this SMASS class. The spectrum of this asteroid also displays a band feature near 2.9 μm that indicate the presence of a hydrated mineral. This suggests that the asteroid has undergone significant water-based alteration.[2]
335 Roberta was identified as one of three asteroids that were likely to be a parent body for chondrites along with 449 Hamburga and 304 Olga.[5] All three asteroids were known to have low-albedo (not reflect as much light) and be close to "meteorite producing resonances".[5] Chrondrites are the most common type of meteor found on Earth, accounting for over 80% of all meteors.[6] They are named for the tiny spherical silicate particles that are found inside them (those particles are called chondrules).[6]
References
- 1 2 3 4 5 "335 Roberta", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-04-07
- 1 2 Yang, Bin; Jewitt, David (September 2010), "Identification of Magnetite in B-type Asteroids", The Astronomical Journal 140 (3): 692–698, arXiv:1006.5110, Bibcode:2010AJ....140..692Y, doi:10.1088/0004-6256/140/3/692
- ↑ "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), retrieved 2013-04-07.
- ↑ Warner, Brian D.; et al. (December 2007), "Lightcurve Analysis of 335 Roberta", The Minor Planet Bulletin 34 (4), p. 99, Bibcode:2007MPBu...34...99W.
- 1 2 Lunar and planetary science: abstracts of papers submitted to the ... Lunar and Planetary Science Conference, Volume 27, Part 1 - Lunar and Planetary Institute, Jan 1, 1996
- 1 2 ASU - Chondrites
External links
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