817 Annika
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| Discovery A | |
|---|---|
| Discoverer | Max Wolf |
| Discovery date | February 6, 1916 |
| Alternate designations B |
1916 YW |
| Category | Main belt (Eunomia family) |
| Orbital elements C | |
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| Eccentricity (e) | 0.179 |
| Semi-major axis (a) | 387.3 Gm (2.589 AU) |
| Perihelion (q) | 317.9 Gm (2.125 AU) |
| Aphelion (Q) | 456.6 Gm (3.053 AU) |
| Orbital period (P) | 1521.586 d (4.20 a) |
| Mean orbital speed | 18.36 km/s |
| Inclination (i) | 11.345° |
| Longitude of the ascending node (Ω) |
125.701° |
| Argument of perihelion (ω) |
284.937° |
| Mean anomaly (M) | 224.421° |
| Physical characteristics D | |
| Dimensions | 22 km[1] |
| Mass | ~1.5×1016 kg (estimate) |
| Density | ~2.7 g/cm³ (estimate)[3] |
| Surface gravity | ~0.008 m/s² (estimate) |
| Escape velocity | ~0.013 km/s (estimate) |
| Rotation period | 0.440 d [2] |
| Spectral class | S-type asteroid |
| Absolute magnitude | 10.80 |
| Albedo (geometric) | 0.174 |
| Mean surface temperature |
~169 K max: 264K (-9° C) |
817 Annika is a minor planet orbiting the Sun.
[edit] References
- PDS lightcurve data
-
G. A. Krasinsky et al Hidden Mass in the Asteroid Belt, Icarus, Vol. 158, p. 98 (2002).
[edit] External links
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