335 Roberta
Large main belt asteroid
From Wikipedia, the free encyclopedia
335 Roberta is a large main belt asteroid. It was discovered on 1 September 1892, by German astronomer Anton Staus at Heidelberg Observatory.[3] Roberta was the 12th asteroid that was discovered using photography, and the only asteroid discovery made by Staus.[4]
Lightcurve-base 3D-model of 335 Roberta. | |
| Discovery | |
|---|---|
| Discovered by | Anton Staus |
| Discovery date | 1 September 1892 |
| Designations | |
| (335) Roberta | |
Named after | Carl Robert Osten-Sacken |
| 1892 C | |
| Main belt | |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 123.58 yr (45137 d) |
| Aphelion | 2.9014 AU (434.04 Gm) |
| Perihelion | 2.04926 AU (306.565 Gm) |
| 2.47530 AU (370.300 Gm) | |
| Eccentricity | 0.17212 |
| 3.89 yr (1422.5 d) | |
Average orbital speed | 18.93 km/s |
| 355.460° | |
| 0° 15m 11.095s / day | |
| Inclination | 5.1005° |
| 148.454° | |
| 140.006° | |
| Earth MOID | 1.03587 AU (154.964 Gm) |
| Jupiter MOID | 2.2733 AU (340.08 Gm) |
| TJupiter | 3.456 |
| Physical characteristics | |
| Dimensions | 89.07±2.0 km[1] |
| 12.054 h (0.5023 d) | |
| 0.0580±0.003[1] 0.058[2] | |
| B–V = 0.624 U–B = 0.235 FP (Tholen) B (SMASS)[1] | |
| 8.96[1] | |
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.[5]
Under the SMASS classification taxonomy, this asteroid is listed as a B-type; 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.[6] All three asteroids were known to have low-albedo (not reflect as much light) and be close to "meteorite producing resonances".[6] Chrondrites are the most common type of meteor found on Earth, accounting for over 80% of all meteors.[7] They are named for the tiny spherical silicate particles that are found inside them (those particles are called chondrules).[7]
