8 Flora

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8 Flora
8 Flora VLT (2021), deconvolved.pdf
Discovery
Discovered by J.R. Hind
Discovery date18 October 1847
Designations
(8) Flora
Pronunciation /ˈflɔːrə/
Named after
Flōra
Main belt (Flora family)
Adjectives Florian /ˈflɔːriən/
Symbol Flora symbol (bold).svg (historical)
Orbital characteristics [1]
Epoch 17.0 October 2024
(JD  2460600.5)
Aphelion 2.55  AU (381 million  km)
Perihelion 1.86 AU (278 million km)
2.20 AU (329 million km)
Eccentricity 0.15658
3.27 yr (1192.70 d)
78.2°
Inclination 5.890°
110.85°
1 February 2024
285.4°
Earth  MOID 0.873 AU (130.6 million km)
Jupiter  MOID 2.877 AU (430.4 million km)
TJupiter 3.642
Proper orbital elements [2]
2.2014  AU
Proper eccentricity
0.1449
Proper inclination
5.574°
Proper mean motion
110.2  deg  / yr
3.26679 yr
(1193.194 d)
Precession of perihelion
32.017  arcsec  / yr
Precession of the ascending node
−35.51  arcsec  / yr
Physical characteristics
Dimensions (154 km × 148 km × 127 km) ± (7 km × 6 km × 4 km) [3]
136  km × 136  km × 113  km [4]
145 km × 145 km × 120 km [5]
146±2 km [3]
128 km [4]
147.491±1.025 km [1]
Flattening 0.18 [a]
Mass (4.0±1.6)×1018 kg [3]
(6.62±0.84)×1018 kg [b] [6]
Mean density
2.4±1.0 g/cm3 [3]
3.04±1.39 g/cm3 [6]
12.865 h (0.5360 d) [1]
0.224 (calculated) [3]
0.226±0.041 [1]
S [1]
7.9 [7] to 11.6
6.54 [3]
6.61 [1]
0.21" to 0.053"

    8 Flora is a large, bright main-belt asteroid. It is the innermost large asteroid: no asteroid closer to the Sun has a diameter above 25 kilometres (20% that of Flora), and not until 20-km 149 Medusa was discovered was an asteroid known to orbit at a closer mean distance. [8] It is the seventh-brightest asteroid with a mean opposition magnitude of +8.7. [9] Flora can reach a magnitude of +8.1 at a favorable opposition near perihelion, such as occurred in November 2020 when it was 0.88  AU (132 million  km ; 340  LD ) from Earth. [10]

    Contents

    Discovery and naming

    Flora was discovered by J. R. Hind on 18 October 1847. It was his second asteroid discovery after 7 Iris.[ citation needed ]

    The name Flora was proposed by John Herschel, from Flora, the Latin goddess of flowers and gardens, wife of Zephyrus (the personification of the West wind), and mother of Spring. The Greek equivalent is Chloris, who has her own asteroid, 410 Chloris, but in Greek 8 Flora is also called 8 Chloris (8 Χλωρίς).[ citation needed ] The old iconic symbol for 8 Flora has been variously rendered as Flora symbol (fixed width).svg , Flora symbol (simple, fixed width).svg , etc. It is in the pipeline for Unicode 17.0 as U+1CEC2 𜻂 ( Flora symbol (fixed width).svg ). [11] [12]

    Characteristics

    The orbit of 8 Flora compared with the orbits of Earth, Mars and Jupiter FloraOrbit.png
    The orbit of 8 Flora compared with the orbits of Earth, Mars and Jupiter
    Size comparison: the first 10 asteroids profiled against Earth's Moon. Flora is third from the right. Moon and Asteroids 1 to 10.svg
    Size comparison: the first 10 asteroids profiled against Earth's Moon. Flora is third from the right.

    Lightcurve analysis indicates that Flora's pole points towards ecliptic coordinates (β, λ) = (16°, 160°) with a 10° uncertainty. [5] 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.[ citation needed ]

    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. [13] This meteorite type comprises 35% of meteorites impacting the Earth. [14]

    Observational history

    During an observation on 25 March 1917, 8 Flora was mistaken for the 15th-magnitude star TU Leonis, which led to that star's classification as a U Geminorum cataclysmic variable star. [15] Flora had come to opposition on 1917 February 13, 40 days earlier. [15] This mistake was uncovered only in 1995. [15] [16]

    On 26 July 2013, Flora at magnitude 8.8 occulted the star 2UCAC 22807162 over parts of South America, Africa, and Asia. [17]

    In the 1968 science-fiction film The Green Slime , an orbital perturbation propels the asteroid Flora into a collision course with Earth.

    Notes

    1. Flattening derived from the maximum aspect ratio (c/a): , where (c/a) = 0.82±0.05. [3]
    2. (3.33±0.42)×10−12 M

    Related Research Articles

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    <span class="mw-page-title-main">5 Astraea</span> Large asteroid

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    <span class="mw-page-title-main">7 Iris</span> Large main-belt asteroid

    7 Iris is a large main-belt asteroid and possible remnant planetesimal orbiting the Sun between Mars and Jupiter. It is the fourth-brightest object in the asteroid belt. 7 Iris is classified as an S-type asteroid, meaning that it has a stony composition.

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    9 Metis is one of the larger main-belt asteroids. It is composed of silicates and metallic nickel-iron, and may be the core remnant of a large asteroid that was destroyed by an ancient collision. Metis is estimated to contain just under half a percent of the total mass of the asteroid belt.

    <span class="mw-page-title-main">11 Parthenope</span> Main-belt asteroid

    11 Parthenope is a large, bright main-belt asteroid.

    <span class="mw-page-title-main">17 Thetis</span> Main-belt asteroid

    17 Thetis is a stony asteroid from the inner regions of the asteroid belt, approximately 90 kilometers in diameter. It was discovered on 17 April 1852, by German astronomer Robert Luther at Bilk Observatory in Düsseldorf, Germany who deferred to Friedrich Wilhelm August Argelander the naming his first asteroid discovery after Thetis from Greek mythology. Its historical symbol was a dolphin and a star; it is in the pipeline for Unicode 17.0 as U+1CECA 𜻊.

    <span class="mw-page-title-main">18 Melpomene</span> Main-belt asteroid

    18 Melpomene is a large, bright main-belt asteroid that was discovered by J. R. Hind on 24 June 1852, and named after Melpomenē, the Muse of tragedy in Greek mythology. Its historical symbol was a dagger over a star; it is in the pipeline for Unicode 17.0 as U+1CECB 𜻋.

    <span class="mw-page-title-main">19 Fortuna</span> Main-belt asteroid

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    <span class="mw-page-title-main">28 Bellona</span> Main-belt asteroid

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    <span class="mw-page-title-main">29 Amphitrite</span> Main-belt asteroid

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    <span class="mw-page-title-main">146 Lucina</span> Main-belt asteroid

    146 Lucina is a main-belt asteroid that was discovered by Alphonse Borrelly on June 8, 1875, and named after Lucina, the Roman goddess of childbirth. It is large, dark and has a carbonaceous composition. The spectra of the asteroid displays evidence of aqueous alteration.

    <span class="mw-page-title-main">152 Atala</span> Main-belt asteroid

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    410 Chloris is a very large main-belt asteroid that was discovered by Auguste Charlois on January 7, 1896, in Nice. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. The spectrum of the asteroid displays evidence of aqueous alteration. It is the namesake of the Chloris family of asteroids.

    956 Elisa is a Flora asteroid from the inner regions of the asteroid belt, approximately 10.5 kilometers in diameter. It was discovered on 8 August 1921, by German astronomer Karl Reinmuth at the Heidelberg Observatory. The V-type asteroid has a rotation period of 16.5 hours. It was named after Elisa Reinmuth, mother of the discoverer.

    6470 Aldrin, provisional designation 1982 RO1, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter.

    3268 De Sanctis, provisional designation 1981 DD, is a Vestian asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 26 February 1981, by European astronomers Henri Debehogne and Giovanni de Sanctis at ESO's La Silla Observatory in northern Chile. The asteroid was named after the second discoverer. The assumed S-type asteroid has a rotation period of 17 hours.

    3703 Volkonskaya, provisional designation 1978 PU3, is a Vestian asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 9 August 1978, by Soviet astronomers Lyudmila Chernykh and Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. It was named by the discoverers after the Russian princess Mariya Volkonskaya. The V-type asteroid has a rotation period of 3.2 hours. The discovery of its 1.4-kilometer minor-planet moon was announced in December 2005.

    23327 Luchernandez (provisional designation 2001 BE31) is a Florian asteroid from the inner regions of the asteroid belt, approximately 2 kilometers in diameter. It was discovered on 20 January 2001, by astronomers of the LINEAR program at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The asteroid was named for ISEF awardee Lucero Hernandez.

    (11436) 1969 QR is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 3.7 kilometers in diameter. It was discovered on 22 August 1969, by Czech astronomer Luboš Kohoutek at Bergedorf Observatory in Hamburg, Germany.

    References

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