8 Flora
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| Discovery A | |
|---|---|
| Discoverer | J.R. Hind |
| Discovery date | October 18, 1847 |
| Alternate designations B |
none |
| Category | Main belt (Flora family) |
| Orbital elements C | |
|
|
|
| Eccentricity (e) | 0.1561 |
| Semi-major axis (a) | 329.422 Gm (2.202 AU) |
| Perihelion (q) | 277.995 Gm (1.858 AU) |
| Aphelion (Q) | 380.850 Gm (2.546 AU) |
| Orbital period (P) | 1193.549 d (3.27 a) |
| Mean orbital speed | 19.95 km/s |
| Inclination (i) | 5.886° |
| Longitude of the ascending node (Ω) |
111.011° |
| Argument of perihelion (ω) |
285.128° |
| Mean anomaly (M) | 156.401° |
| Physical characteristics D | |
| Dimensions | 145×145×120 km [1] [4] |
| Mass | ~3.6×1018 kg |
| Density | ~2.7 g/cm³ [5] |
| Surface gravity | ~0.045 m/s² |
| Escape velocity | ~0.081 km/s |
| Rotation period | 0.5363 d (12.87 h) [2] |
| Spectral class | S-type asteroid |
| Absolute magnitude | 6.49 |
| Albedo (geometric) | 0.243 [1] |
| Mean surface temperature |
~180 K max: 276 K (+3 °C) |
8 Flora (flor'-ə (key)) is a large, bright main belt asteroid.
Contents |
[edit] Discovery and naming
Flora was discovered by J. R. Hind on October 18, 1847. It was his second asteroid discovery after 7 Iris.
The name Flora was proposed by John Herschel, from Flora, the Latin goddess of flowers and gardens, wife of Zephyrus (the personnification of the West wind), mother of Spring, and whose Greek equivalent is Chloris (who has her own asteroid, 410 Chloris).
[edit] Characteristics
Lightcurve analysis indicates that Flora's pole points towards ecliptic coordinates (β, λ) = (16°, 160°) with a 10° uncertainty [4]. This gives an axial tilt of 78°, plus or minus ten degrees.
Flora is the parent body of the Flora family of asteroids, and by far the largest member, comprising about 80% of the total mass of this family. Nevertheless, Flora was almost certainly disrupted by the impact(s) that formed the family, and is probably a gravitational aggregate of most of the pieces.
Flora's spectrum indicates that its surface composition is a mixture of silicate rock (including pyroxene and olivine) and nickel-iron metal. Flora, and the whole Flora family generally, are good candidates for being the parent bodies of the L chondrite meteorites [6]. This meteorite type comprises about 38% of all meteorites impacting the Earth.
[edit] Trivia
During an observation on March 25, 1917, 8 Flora was mistaken for the star TU Leonis, which led to that star's classification as a U Geminorum cataclysmic variable star. This mistake was uncovered only in 1995 [3].
[edit] Aspects
[edit] References
- Planetary Data System Small Bodies Node, lightcurve parameters
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L. D. Schmadel et al TU Leonis = (8) Flora: the non-existence of a U Geminorum star, Astronomy & Astrophysics, Vol. 312, p. 496 (1996).
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J. Torppa et al Shapes and rotational properties of thirty asteroids from photometric data, Icarus, Vol. 164, p. 346 (2003).
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G. A. Krasinsky et al Hidden Mass in the Asteroid Belt, Icarus, Vol. 158, p. 98 (2002).
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D. Nesvorný et al The Flora Family: A Case of the Dynamically Dispersed Collisional Swarm?, Icarus, Vol. 157, p. 155 (2002).
- IAUC 6174
[edit] External links
- shape model deduced from lightcurve
- "Announcement of discovery of Flora", MNRAS 8 (1848) 82
- Orbital simulation from JPL (Java)
- 8 Flora at opposition Nov 15th, 2007 (0.89AU from Earth)
| Minor planets | ||
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| Previous minor planet | 8 Flora | Next minor planet |
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| Vulcanoids | Near-Earth asteroids | Main belt | Jupiter Trojans | Centaurs | Damocloids | Comets | Trans-Neptunians (Kuiper belt · Scattered disc · Oort cloud) |
| For other objects and regions, see: asteroid groups and families, binary asteroids, asteroid moons and the Solar system For a complete listing, see: List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names. |
