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 Regents Park, London on the evening of 18th October 1847. This was Hinds 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.]


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 Augusts 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. Bishops Observatory, near the star Bessel v.48, of Weisses 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 Herschels 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 Enckes 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 Enckes 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

  1. Encke, J.F.., On a New Solution of the Problem of Planetary Perturbation.;
    MNRAS., 13, 207 (1853)
  2. Hind, J.R., Announcement of Discovery of Flora, Oct 18, 1847; MNRAS., 8, 1 (1847)
  3. Hind, J.R., Observation of Flora : Elements; MNRAS., 8, 18 (1847a)

Nature of Flora

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.


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.


[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  ′                              
 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

Highlights for FLORA 2012

Oppositions and Conjuctions: 2012-2020

Opposition   Conjunction
05 Aug 2012  26 May 2007

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.


Last Update : 26th August 2012

Southern Astronomical Delights © (2012)

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