The International Astronomical Union (see IAU.org ) was founded in 1919 and regards itself to be the naming authority for astronomical bodies .
In addition, in 1930 the IAU fixed the present boundaries of the stellar (starry) constellations by adopting a system devised by Joseph Delporte, which fixed those boundaries along lines of right ascension and declination for the epoch B1875.0 , a so-called Besselian epoch (365.242198781 days), which has since been superseded in mainstream astronomy by Julian epochs (based on Julian years of 365.25 days and calculated by the formula
J = 2000.0 + (Julian date - 2451545.0)/365.25.
The fixing of starry constellations at its present number of 88 had the drawback that not all ancient constellations are included in this system, nor did the ancients necessarily use the exact same stars for a given constellation as used by more ancient astronomers.
See generally in this regard, Richard Hinckley Allen, Star Names: Their Lore and Meaning, Dover, N.Y. 1963, see StarPath (the book online) or Amazon.
Moreover, different cultures saw the stars somewhat differently in terms of their representations, even if there are substantial overlaps among cultures in the way they saw the sky.
Finally, the present "fixed" constellations give the appearance that the stellar constellations were always viewed the same way we view them today, which is simply false.
The IAU has now dimply redefined what a "planet" is and in the process has eliminated Pluto from its previous classification as a planet. See the CNN article, Pluto gets the boot
As reported there by Associated Press:
"For now, membership will be restricted to the eight "classical" planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.The idea that sheer "size" (i.e. mass) and gravitational effect rather than "orbit" should be the determining factor for defining a planet shows in our opinion a serious lack of insight into the nature of the universe, which seems to us to be defined more by principles of "distribution" of matter, rather than by the "mass" of the matter per se. Indeed, the ancient Greeks (as in our opinion also ancient man) saw the stellar constellations as consisting not only of stars of the heavens but also of the spaces inbetween. Modern astronomers have often lost sight of the "spaces" inbetween, also as far as the planets are concerned.
Much-maligned Pluto doesn't make the grade under the new rules for a planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."
Pluto is automatically disqualified because its oblong orbit overlaps with Neptune's.
Instead, it will be reclassified in a new category of "dwarf planets," similar to what long have been termed "minor planets." The definition also lays out a third class of lesser objects that orbit the sun -- "small solar system bodies," a term that will apply to numerous asteroids, comets and other natural satellites."
Not only the Titius-Bode Law (more correctly called a "rule of the distribution of planetary mass by orbits""), but also an analysis of other known orbital systems such as the moons of Jupiter, shows that there is always an orderly "spacing" of "planetary" bodies around an orbited object.
In fact, according to the orderly spacing of objects around the Sun in our own Solar System, it is not only the Asteroid Belt (including Ceres) - which appears to us to be a disintegrated planet at that location - but also the "brothers" Neptune and Pluto (whose orbits overlap) should be regarded as planetary orbits, because their astronomical spacing around the Sun follows an orderly orbital system- in the case of Pluto, it is Pluto and not Neptune which actually occupies the orbital position predicted by the Titius-Bode Law. Keeping Neptune but throwing Pluto out of this system is just ludicrous.
As written at the Wikipedia :
"One plausible explanation other than chance is that orbital resonance from major orbiting bodies creates regions around the Sun that are free of long-term stable orbits. Results from simulation of planetary formation seem to support the idea that laws like the Titius-Bode law are a natural consequence of planetary formation, according to the current theories in this area.The elimination of Pluto as a "planet" by the IAU does not take orbitals of heavenly bodies into account, which in our view is a grievous mistake, since it is not size (mass) which should be determinative of planetary status, but rather the orbital location of the orbiting body, regardless of its size.
Dubrulle and Graner have shown that power-law distance rules are a natural consequence of collapsing-cloud models of planetary systems possessing two symmetries: rotational invariance (the cloud and its contents are axially symmetric) and scale invariance (the cloud and its contents look the same on all length scales), the latter being a feature of many phenomena considered to play a role in planetary formation, such as inverse-square force fields and turbulence."
We think the IAU has made a serious mistake.