F L O R A was the eighth asteroid discovered, having the
principal distinction as the closest Earth approaching body of the
significantly large main belt asteroids. It was found by John Russell
Hind from Regent’s Park, London on the
evening of 18th October 1847. This was
Hind’s second asteroidal discovery for
1847, after earlier finding the previous seventh minor planet, (7)
Iris, just two months beforehand. Hind found Flora using a visual
chart in which the position matched no known star. Shining at 9th
magnitude in Leo, Flora soon revealed some small motion on the same
night, confirming that it was a new minor planet. As Hind (1847)
says; “…I had no hesitation in
deciding of its nature.” Within
weeks the brightness continued to climb until the minor planet
reached its maximum of around 8th magnitude.
In total number, John Hind found nine new asteroids between
1847 and 1853. First of his was (7) Iris, then (8) Flora,
followed in oder, (12) Victoria [13th Sep 1850] and (14)
Irene [19th May 1851]. He then followed with four
discoveries in 1852, namely, (18) Melpomene [24th Jun],
(19) Fortuna [22nd Aug], (22) Kalliope [16th Nov] then
(23) Thalia [15th Dec]. A final one was (27) Euterpe
[08th Nov 1853.]
FLORA DATA
Discoverer : J. R. Hind Date : 18th October 1847 Satellites : 0 Diameter : 145×145×120 km. Polar Tilt : ° ? Period (P) : 3.27 years Synodic Period : 475.7 days Orbital Velocity : 20.0 km.s-1 Perihelion (q) : 1.86 A.U. Aphelion (Q) : 2.55 A.U. Eccentricity (e) : 0.1561 Inclination (i) : 5.887° Mass : c. 3.8×1018 kg. Mean Density : c. 2.7 g.cm-3 Mean Distance : 2.02 AU or 3.291×108 km Sidereal Rotation : 12.9 hr. Mean Sidereal Rotation : 0.5363 d. Maximum Diameter : 0.21″ (arcsec) Minimum Diameter : 0.05″ (arcsec) Maximum Magnitude : 7.9 Minimum Magnitude : 11.5
After Hind's Discovery
Amazingly within six short weeks, Hind had sufficient information
to declare some early orbital elements for Flora that he published in
August’s RAS Monthly Notices (1847).
Flora was surprising in several ways, as then found as the closest
orbiting asteroid to the Sun. He realised Iris was being
significantly influenced by the gravitational field of Vesta, Ceres
and Pallas, producing observable perturbations. Furthermore, the
inclinations were very similar to (5) Astraea and (7) Iris. Hind
(1847a) also provided an ephemeris, which would be useful when Flora
emerged from its conjunction in 1848 — a remarkable achievement
for the day. When recovered in 1848, several observers published
updated orbital elements, and by ending 1848, Hind produce his third
computation of the orbit. Appearing in the
“Report to the Twenty-eigth Annual
General Meeting”, MNRAS.,
8, pg. 82 (1848) gives the discovery summary and about the
speedy calculation of the orbital elements, in which the report
clearly and openly says;
“On the night of
October 18th, another small planet was detected by Mr. Hind, at Mr.
Bishop’s Observatory, near the star
Bessel v.48, of Weisse’s Catalogue,
with which it was compared. At the time of discovery it was not very
far from its stationary point. During the month of November it
equalled in brightness stars of the 8th magnitude, but at present it
is a little below the 9th. The elements of this planet, which has
received the name of Flora on Sir John
Herschel’s proposition, have already
been determined with a considerable degree of accuracy. There appears
to be no instance on record where the orbits of various astronomers
for a planetary periodical comet have agreed so well together : the
values of the mean daily motion in the several orbit, do not differ
more than 7′ or 3′, and the other elements are very
accordant. The period of revolution of Flora is shorter than that of
any other of her companion planets. The symbol adopted for her
designation is the figure of a flower. Observations of the planet
will be practicable for some months longer, and an ephemeris,
extending to May 1, is given in the last number of our Monthly
Notices.”
Johann Encke and Flora
By 1849, many astrometric measures were achieved, and much work
was undertaken to understand the effects of perturbations either from
other minor planets or by Jupiter and Saturn — hopefully
discovering how this changed various predicted planetary orbits. One
of first was by Dr. F. Brünnow from Berlin Observatory in April
1853, as communicated by Professor Encke to the Astronomer Royal for
publication in the RAS Monthly Notices.
In the following years, various new attempts were made to refine
calculations and perturbation influences. Johann Franz
Encke (1791-1865). This brilliant and masterful mathematician,
applied his genius to problems of planetary and asteroidal orbits,
especially with subtle gravitation interactions by other bodies.
Encke became in 1844 became a professor of astronomy and was
well-respected throughout Europe and in England. His main fame was
the substantial work with the orbital parameters of 3.3 year-long
periodic Encke’s Comet
(2P/Encke), but this in fact was only the beginning of his fame. For
example, in 1837 his careful observations of Saturn and its rings,
describes for the first time Encke’s
Division. One of the important investigations, that began in the
1830s, and took up much his later career, was working on orbital
analysis of other comets. This expanded to meteor showers and orbits
of newly discovered asteroids. Discovery of (8) Flora became the
milestone that reinforced his new ideas on perturbation theory. This
view was in retrospect of the validation or continuation of a working
method in calculating elliptical orbits from just three
astrometric observations. Today these methods still are used. By
1851, Encke had worked out how to express planetary perturbations
using the simpler to apply rectangular co-ordinates. This allowed
additional small changes to more accurately calculate ephemerides
— especially of the other planets and the ever expanding
numbers of newly discovered asteroids.
Later in 1875, the comet observer Johann Gottfried Galle
(1812-1910), in Breslau, Germany, became the first to use the Flora
to measure the solar distance. This found the solar parallax
value, calculating the astronomical unit (AU) as 148.290 million
kilometres.
Historical References
Encke, J.F.., “On a New Solution
of the Problem of Planetary
Perturbation.”; MNRAS.,
13, 207 (1853)
Hind, J.R., “Announcement of
Discovery of Flora, Oct 18, 1847”;
MNRAS., 8, 1 (1847)
The highly notable 19th Century English observer, Sir John
Herschel, assigned its original name, and even assigned the quite
appropriate flowery symbol of the rose! Even during opposition, Flora
needs some form of optical aid to see, and will rarely rise above 8th
magnitude. Lying at the mean distance of 2.02 AU, and with an orbital
period of 3.27 years, this potato-shaped asteroid averages about 135
km. across. Mostly, the asteroidal orbit remains close to the
ecliptic, though the inclination of 5½° — notably
very similar to the Moon — means Flora can range between
±31° in declination. Observations of its light shows
slight fluctuations in brightness, suggesting the 12h 54m rotation.
Composition seems likely to be an aggregate of rubble-like material
that is mainly rich in nickel, iron and silicates.
Mythology
Flora is the Roman goddess of the gardens and specifically
flowers, being similar to the Greek Nymph of Chloris[1] or Khloris). She is the lovely and joyous
daughter of Spring, sometimes the Seasons, being the Greek goddess,
Persephone[2] or Kora, whose Roman equivalent is
Proserpina (Persipina) or Libera.
Flora was to marry Zephyros, the god of the West Wind and
the bringer of spring rains that cultivate the earth, notoriously
after she being earlier kidnapped by him. Her own child to be born
was Carpos or Karpos, who is somtimes also seen as the
Greek goddess of fruit. Flora is always commonly portrayed as a very
dainty and delicate child, whose kind generous love and notable
rose-perfumed breath nurtures the colourful flowers to bloom and
eventually propagate — traits probably inherited from her
mother.
Also goddess Chloris is more often associate with the Greek
word khloros, often meaning the natural colours of green to
pale green. Here is the direct association with the greens of leaves
trees and plants. Still this analogy here also seems a little odd, as
Chloris has the associated word with the greenish deadly poisonous
gas, Chlorine, the 17th gaseous chemical element. Yet, chlorine is
also associated with the chemical compound of salt or sodium
chloride (NaCl), the much-needed substance for continued life
here on Earth and also mostly dissolved in the sea water in the
oceans! Here we again see, like most of the stories and myths Greek
gods and goddesses, that even the most kindest, beautiful or highly
elegant of these immortals always seems to have some negative
dark or dopplegänger (evil-twin) sides. Mostly their natures
reaps good, but they can brutally capriciously dand ish-out their own
vengeful wrath by inflicting severe punishment or adding to the
suffering to those straying mortals they deem unworthy or undeserving
for their actions or foibles.
Flora own embellished mythology or folklore appears in many
different cultures. She is certainly related to the benign and
good-natured fairies and the elves (the Welsh
ellyllon whose magical stories are often adored and imagined
in childhood by very young girls. Adoption also has come from the
Celts and the Norse, where these imaginary creatures are considered
minor divine sprits among the natural world — and parallels
similar legends of the water nymphs (See
Neptune Mythology) or satyers,
etc.
Endnotes
[1] Chloris (410) is another main
belt minor planet discovered by Auguste Charlois on 7th January 1896
from Nice. Chloris is surprisingly large, having the mean diameter of
124 km., so we would expect it to be brighter than it appears
telescopically. No doubt this C-type object with low albedo, probably
suggesting composed of various carbonaceous substances. Chloris has
the mean orbital period of 4.51 years at the mean distance of 2.729
AU. Its orbit is fairly eccentric and inclined by 10.9° to the
ecliptical plane.
Chloris was notable during 2008, being predicted to occultate 8.7
magnitude Taurus star, HIP 21953 on the 12th March. Eclipse
duration was expected to last about 5½ seconds, whose drop in
brightness was predicted to be by 5.9 magnitudes at minimum. The 155
kilometre wide path crossed much of the Indian Ocean but should have
been visible, even though it was merely 10° from the horizon,
from the top half of the Northern Territory in Australia. At the time
of writing, no observations had been received of this event, likely
because of the general placement of the path. Another event occurred
on the 9th April 2008, which was visible from western Africa,
occultating an 12th magnitude star.
Yet a third event is predicted for 7th February 2009, where 12.7
magnitude Chloris will occultate a 9.7 magnitude star for about 8.3
seconds or so. The path is expected to travel through northern India,
Bangladesh, northern Vietnam and on to the Philippines, before
travelling across the mid-western Pacific Ocean.
[2] Persephone (399) is the main
belt minor planet discovered by Max Wolf on 23rd February 1895 from
Heidelberg, Germany. Its diameter is 41.9 km., whose mean orbital
period is 5.34 years at the mean distance of 3.057 AU.
Flora Ephemeris 2012
*********************************************************
0h UT (J2000) Mag Δ r El. Con
DATE R.A. Decl. V A.U. A.U. o
hh mm.m o ′
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07 Jan 12 30.7 +02 36 10.7 1.988 2.363 100 Vir
21 Jan 12 38.7 +02 36 10.5 1.832 2.384 112 Vir
04 Feb 12 41.7 +03 14 10.2 1.690 2.403 126 Vir
18 Feb 12 38.9 +04 28 10.0 1.574 2.421 141 Vir
03 Mar 12 30.5 +06 10 09.7 1.497 2.439 156 Vir
17 Mar 12 18.0 +08 02 09.4 1.469 2.455 170 Vir
31 Mar 12 04.3 +09 37 09.6 1.494 2.469 164 Vir
14 Apr 11 52.6 +10 37 09.9 1.571 2.483 149 Leo
28 Apr 11 45.1 +10 53 10.2 1.691 2.495 134 Leo
12 May 11 43.0 +10 29 10.5 1.842 2.506 120 Leo
26 May 11 45.8 +09 31 10.8 2.014 2.516 108 Vir
09 Jun 11 52.9 +08 08 11.0 2.196 2.524 097 Vir
23 Jun 12 03.4 +06 26 11.2 2.382 2.531 086 Vir
07 Jul 12 16.7 +04 31 11.3 2.565 2.537 077 Vir
21 Jul 12 32.1 +02 25 11.4 2.740 2.541 068 Vir
04 Aug 12 49.3 +00 12 11.5 2.904 2.544 060 Vir
18 Aug 13 07.9 -02 03 11.6 3.053 2.546 051 Vir
01 Sep 13 27.7 -04 21 11.6 3.184 2.546 043 Vir
15 Sep 13 48.6 -06 37 11.6 3.296 2.544 035 Vir
29 Sep 14 10.6 -08 50 11.6 3.386 2.542 028 Vir
13 Oct 14 33.4 -10 58 11.5 3.452 2.537 020 Lib
27 Oct 14 57.1 -12 57 11.4 3.494 2.532 012 Lib
10 Nov 15 21.6 -14 46 11.3 3.509 2.525 005 Lib
24 Nov 15 46.7 -16 23 11.3 3.499 2.517 005 Lib
08 Dec 16 12.3 -17 45 11.4 3.462 2.507 012 Sco
22 Dec 16 38.4 -18 52 11.4 3.399 2.496 020 Oph
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Highlights for FLORA 2012
Oppositions and Conjuctions: 2012-2020
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Opposition Conjunction
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05 Aug 2012 26 May 2007
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Disclaimer : The user applying this
data for any purpose forgoes any liability against the author. None
of the information should be used for either legal or medical
purposes. Although the data is accurate as possible some errors might
be present. Onus of its use is placed solely with the user.