8 Flora

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 kilometers (20% that of Flora), and not until 20-km 149 Medusa was discovered was an asteroid known to orbit at a closer mean distance.^[7] It is the seventh-brightest asteroid with a mean opposition magnitude of +8.7.^[8] 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 astronomical units from Earth.^[9]

Discovery and naming

Flora was discovered by J. R. Hind on 18 October 1847. It was his second asteroid discovery after 7 Iris.^[10]

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 , , etc. It was added to Unicode 17.0 as U+1CEC2 𜻂 ().^[10][11] The original description for the symbol described it as a flower, but later authors per Schmadel (2012) identified it as the Rose of England.^[10]

Characteristics

Lightcurve analysis indicates that Flora's pole points towards ecliptic coordinates (β, λ) = (16°, 160°) with a 10° uncertainty.^[3] 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.^[12] This meteorite type comprises 35% of meteorites impacting the Earth.^[13]

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.^[14] Flora had come to opposition on 1917 February 13, 40 days earlier.^[14] This mistake was uncovered only in 1995.^[14][15]

On 26 July 2013, Flora at magnitude 8.8 occulted the star 2UCAC 22807162 over parts of South America, Africa, and Asia.^[16]

Notes

1. ^ Flattening derived from the maximum aspect ratio (c/a): f=1-\frac{c}{a}, where (c/a) = 0.82 ± 0.05.^[1]
2. ^ 3.33 ± 0.42×10⁻¹²

References

1. ^ P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
2. ^ Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 2013-07-02. Retrieved 2008-11-27.
3. ^ Torppa, Johanna; Kaasalainen, Mikko; Michalowski, Tadeusz; Kwiatkowski, Tomasz; Kryszczynska, Agnieszka; Denchev, Peter et al. (August 2003). "Shapes and rotational properties of thirty asteroids from photometric data". Icarus. 164 (2): 346–383. Bibcode:2003Icar..164..346T. CiteSeerX 10.1.1.694.1087. doi:10.1016/S0019-1035(03)00146-5. S2CID 119609765
4. ^ "JPL Small-Body Database Browser: 8 Flora". Retrieved 2024-12-20. 2024-11-09 last obs
5. ^ James Baer, Steven Chesley & Robert Matson (2011) "Astrometric masses of 26 asteroids and observations on asteroid porosity." The Astronomical Journal, Volume 141, Number 5
6. ^ Donald H. Menzel & Jay M. Pasachoff (1983). A Field Guide to the Stars and Planets. 2nd ed. Boston, MA: Houghton Mifflin. pp. 391. ISBN 0-395-34835-8.
7. ^ Binsel, Richard P.; Gehrels, Tom and Matthews, Mildred Shapley (editors); Asteroids II; published 1989 by University of Arizona Press; pp. 1038-1040. ISBN 0-8165-1123-3
8. ^ "JAS: The Brightest Asteroids". Archived 25 August 2011 at the Wayback Machine.
9. ^ "Horizons Batch for November 2020". JPL Horizons. Retrieved 2022-11-17.
10. ^ Bala, Gavin Jared & Miller, Kirk (18 September 2023). "Unicode request for historical asteroid symbols". unicode.org. Unicode. Retrieved 26 September 2023.
11. ^ "Miscellaneous Symbols Supplement". unicode.org. The Unicode Consortium. 2025. Retrieved September 9, 2025.
12. ^ Nesvorný, D. et al. (2002). "The Flora Family: A Case of the Dynamically Dispersed Collisional Swarm?". Icarus. 157 (1): 155–172. Bibcode:2002Icar..157..155N. doi:10.1006/icar.2002.6830
13. ^ Grady, Monica (2022). "Meteorites". The Catalogue of Meteorites. Natural History Museum. doi:10.5519/tqfuwle7. Retrieved 28 May 2020.
14. ^ Schmadel, L. D.; Schmeer, P.; Börngen, F. (August 1996). "TU Leonis = (8) Flora: the non-existence of a U Geminorum star". Astron. Astrophys.. 312: 496. Bibcode:1996A&A...312..496S
15. ^ "IAUC 6174"
16. ^ "(8) Flora / 2UCAC 22807162 event on 2013 Jul 26, 00:18 UT". asteroidoccultation.com. Archived 24 July 2013 at the Wayback Machine.

External links

• shape model deduced from lightcurve
• "Announcement of discovery of Flora", MNRAS 8 (1848) 82