Discovery [1] | |
---|---|
Discovered by | C. H. F. Peters |
Discovery site | Clinton, New York |
Discovery date | 9 September 1878 |
Designations | |
(189) Phthia | |
Pronunciation | /ˈθaɪ.ə/ [2] |
A878 RA | |
main-belt | |
Orbital characteristics [3] [4] | |
Epoch 31 July 2016 ( JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 136.18 yr (49739 d) |
Aphelion | 2.5415 AU (380.20 Gm) |
Perihelion | 2.3597 AU (353.01 Gm) |
2.4506 AU (366.60 Gm) | |
Eccentricity | 0.037105 |
3.84 yr (1401.2 d) | |
336.98 ° | |
0° 15m 24.912s / day | |
Inclination | 5.1774° |
203.42° | |
168.03° | |
Physical characteristics | |
Dimensions | 37.66±2.0
km
[3] 40.91 ± 1.36 km [5] |
Mass | (3.84 ± 0.81) × 1016 kg [5] |
Mean
density | 1.07 ± 0.25 g/cm3 [5] |
22.346 h (0.9311 d) [3] [6] | |
0.2310±0.027
[3] 0.1566 ± 0.0349 [7] | |
S [7] ( Tholen) | |
9.33, [3] 9.60 [7] | |
189 Phthia is a bright-coloured, rocky main belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on September 9, 1878 [1] in Clinton, New York and named after Phthia, a region of Ancient Greece.
Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico during 2008 gave a light curve with a period of 22.346 ± 0.001 hours and a brightness variation of 0.26 ± 0.02 in magnitude. [6]