8 Flora

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0
name=8 Flora
symbol=
discoverer=J.R. Hind
discovered=October 18, 1847
alt_names="none"
adjectives=Florian
mp_category=Main belt (Flora family)
epoch=November 26, 2005 (JD 2453700.5)
semimajor=329.422 Gm (2.202 AU)
perihelion=277.995 Gm (1.858 AU)
aphelion=380.850 Gm (2.546 AU)


eccentricity=0.1561
period=1193.549 d (3.27 a)
inclination=5.886°
asc_node=111.011°
arg_peri=285.128°
mean_anomaly=156.401°
avg_speed=19.95 km/s
dimensions=145×145×120 km cite web| url=http://www.psi.edu/pds/archive/astdata04/simps04/diamalb.tab| title= Supplemental IRAS Minor Planet Survey] cite journal| url=http://www.rni.helsinki.fi/~mjk/thirty.pdf| first= J.| last= Torppa| coauthors= et al| title=Shapes and rotational properties of thirty asteroids from photometric data| journal= Icarus| volume= 164| pages= 346| year=2003| doi=10.1016/S0019-1035(03)00146-5]
mass=~3.6×10¹⁸ kg
density=~2.7 g/cm³cite journal| first=G. A.| last= Krasinsky| coauthors= et al| title=Hidden Mass in the Asteroid Belt| journal= Icarus| volume= 158| pages= 98| year=2002| doi=10.1006/icar.2002.6837]
surface_grav=~0.045 m/s²
escape_velocity=~0.081 km/s
rotation=0.5363 d (12.87 h) [cite web| url=http://www.psi.edu/pds/archive/lc.html| title= Planetary Data System Small Bodies Node, lightcurve parameters]
spectral_type=S-type asteroid
magnitude = 7.9cite book | author=Donald H. Menzel and Jay M. Pasachoff | year=1983 | title=A Field Guide to the Stars and Planets | edition=2nd edition | publisher=Houghton Mifflin | pages=p. 391 | location=Boston, MA | id=ISBN 0395348358 ] to 11.6
abs_magnitude=6.49
albedo=0.243 (geometric)
angular_size = 0.21" to 0.053"
single_temperature=~180 K
"max:" 276 K (+3 °C)

8 Flora (pronEng|ˈflɔərə, _la. Flōra) 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 or two-elevenths that of Flora itself, and not until the tiny 149 Medusa was discovered was a single asteroid orbiting at a closer mean distance known [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] . It is the seventh brightest asteroid with a mean opposition magnitude of +8.7 [ [http://jas.org.jo/ast.html The Brightest Asteroids] ] . Flora can reach a magnitude of +7.9 at a favorable opposition near perihelion, such as occurred in November 2007.

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 personification of the West wind), mother of Spring, and whose Greek equivalent is Chloris (who has her own asteroid, 410 Chloris).

Characteristics

Lightcurve analysis indicates that Flora's pole points towards ecliptic coordinates (β, λ) = (16°, 160°) with a 10° uncertainty. 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.cite journal| first=D.| last= Nesvorný| coauthors= et al| title=The Flora Family: A Case of the Dynamically Dispersed Collisional Swarm?| journal=Icarus| volume= 157| pages= 155| year=2002| doi=10.1006/icar.2002.6830] This meteorite type comprises about 38% of all meteorites impacting the Earth.

Notable facts

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. [cite web| url=http://cfa-www.harvard.edu/iauc/06100/06174.html#Item1| title= IAUC 6174] [cite journal| url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1996A%26A...312..496S&db_key=AST&data_type=HTML&format=&high=43a5c7f7b428230
title=TU Leonis = (8) Flora: the non-existence of a U Geminorum star| last=Schmadel| first=L. D.| coauthors= Schmeer, P.; Börngen, F.| journal=Astron. Astrophys.| volume= 312| pages= 496| month=08| year=1996]

References

External links

* [http://www.rni.helsinki.fi/~mjk/thirty.pdf shape model deduced from lightcurve]
* [http://adsabs.harvard.edu//full/seri/MNRAS/0008//0000082.000.html "Announcement of discovery of Flora", MNRAS 8 (1848) 82]
* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=flora;orb=1 Orbital simulation] from JPL (Java)
* [http://home.comcast.net/~kpheider/8Flora_2007.gif8 Flora at opposition Nov 15th, 2007] (0.89AU from Earth)
* — Horizons can be used to obtain a current ephemeris.