Re: Planetary taxonomy: A diplomatic solution


"Paul Schlyter" <pausch@xxxxxxx> wrote in message
news:ed6asl$19d1$1@xxxxxxxxxxxxxxxxx
In article <44f6a129$0$84238$d368eab@xxxxxxxxxxxxxxx>,
Margo Schulter <mschulter@xxxxxxxxxxxxxxx> wrote:
As we've seen over the last week, the planetary taxonomy adopted by
the International Astronomical Union (IAU) on 24 August 2006 has at
once drawn the world's attention to an exciting new perspective on our
solar system, and highlighted a question continuing to provoke lively
debate: "Is a dwarf planet to be regarded as a planet?"

Happily, there is a taxonomic device, familiar in the biological
sciences, which permits us to grant diplomatic recognition, as it
were, to both sides of the question, each of which has its
attractions.

For an astronomer such as Gibor Basri as well as a layperson like
myself, it seems natural to regard the "dwarf" of "dwarf planet" as an
adjective -- much as with "dwarf star."

If "star" is defined as a "natural body with thermonuclear reactions
as its energy source", then a white dwarf isn't a star, because
thermonuclear reactions have ceased in a white dwarf. They are
former stars...... now, does this make white dwarfs "planets"? <g>

According to this, no:

http://www.iau2006.org/mirror/www.iau.org/iau0602/index.html

A planet must be "in orbit around the Sun". Even
if the dwarf were part of a binary with another
main sequence star, it would be a planet, just
as "extra-solar planets" are no longer planets!

Hmmm, is that really the version that was adopted?

George


.

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