Discovery | |
---|---|
Discovered by | Johann Palisa |
Discovery date | 10 December 1879 |
Designations | |
(211) Isolda | |
Pronunciation | /ɪˈzoʊldə/[1] |
Named after | Iseult |
A879 XA, 1912 AB 1912 BA, 1950 FM | |
Main belt | |
Adjectives | Isoldian /ɪˈzoʊldiən/[2] |
Orbital characteristics[3] | |
Epoch 31 July 2016 (JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 136.19 yr (49742 d) |
Aphelion | 3.53270 AU (528.484 Gm) |
Perihelion | 2.5514 AU (381.68 Gm) |
3.04205 AU (455.084 Gm) | |
Eccentricity | 0.16129 |
5.31 yr (1938.0 d) | |
Average orbital speed | 17.08 km/s |
260.142° | |
0° 11m 8.74s / day | |
Inclination | 3.8856° |
263.644° | |
173.522° | |
Physical characteristics | |
Dimensions | 143.19±5.1 km[3] 149.81 ± 6.10 km[4] |
Mass | (4.49 ± 2.43) × 1018 kg[4] |
Mean density | 2.54 ± 1.41 g/cm3[4] |
18.365 h (0.7652 d) | |
0.0602±0.004[3] 0.0598 ± 0.0218[5] | |
C[5] (Tholen) | |
7.89,[3] 7.90[5] | |
Isolda (minor planet designation: 211 Isolda) is a very large, dark main-belt asteroid. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. The spectra of the asteroid displays evidence of aqueous alteration.[6]
It was discovered by Austrian astronomer Johann Palisa on December 10, 1879, in Pola, and named after Isolde, heroine of the legend of Tristan and Iseult.
In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.78 AU. The resulting data yielded an effective diameter of 143 ± 16 km.[7]
Between 2009 and 2021, 211 Isolda has been observed to occult seven stars.