335 Roberta

From Wikipedia, the free encyclopedia
Jump to: navigation, search
335 Roberta
Discovered by Anton Staus
Discovery date September 1, 1892
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)
18.93 km/s
Inclination 5.093°
Physical characteristics
Dimensions 89.1 km[1]
12.054 h[1]
Albedo 0.058[2]
Spectral type

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]


  1. ^ a b c d e "335 Roberta", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-04-07 
  2. ^ a b 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 
  3. ^ "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), retrieved 2013-04-07. 
  4. ^ Warner, Brian D. et al. (December 2007), "Lightcurve Analysis of 335 Roberta", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 34 (4): 99, Bibcode:2007MPBu...34...99W.