SUBJECT: THE AGE OF THE PLEIADES FILE: UFO2654
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Ok... here's the information I have been able to dig out of various
sources of astronomical data including "The Astronomy Databook",
Gaposchkin's "Stars and Clusters" and Pasachoff's "Astronomy" From the
Earth to the Universe" about the Pleiades.
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The age of the Pleiades:
The age of star clusters and how we go about obtaining such data is
probably best discussed in Cecila Payne-Gaposchkin's "Stars and
Clusters" (Havard Univ. Press). Measuring the age of a cluster is a
difficult chore and any figures must be taken as estimates rather than
exact numbers. Basically, stars of different mass, spectral types and
luminosities evolve at different rates. A blue-white O type supergiant
is consuming its mass at a furious rate and only has a very short life
expectancy measured in a few millions or tens of millions of years.
Smaller, cooler stars like the Sun (G3 type) are much more sparing of
their mass and the sun is estimated to have a lifespan of around 10
billion years. Red dwarf type stars may last many more billions of
years. The life of a star is measured not from the moment of its
"birth" until the time it ceases to exist, but is a measure of how long
that star will exist as a "main sequence" star - meaning how much of
its life will be spent in a certain area on the Hertzsprung-Russell
diagram. A star like the sun may spend millions of years forming out of
the galactic gas, a short time as a proto-star, 10 billion years as a
main sequence star, millions of years as a red giant...etc. However,
its life is measured in terms of how long on the main sequence.
The estimates of the age of the Pleiades rest right around 100,000,000
years making it a very young cluster in terms of the age of the galaxy.
Many of even the smaller, fainter stars have not even reached the main
sequence yet, while the big, bright hot members have already expended
much of their fuel and are moving off the main sequence. Such a cluster
is a poor prospect for life based on the evolution of life on earth.
The chances of life arising on any planets orbiting Pleiadian stars is
probably good, but the chances of intelligent life arising in such a
short period - again, based on the only model we have studied - is
slim. It took 4 billion years for intelligent life to arise on earth,
and the chances of it happening in less than 3% of that time is not
considered likely.
The Distance to the Pleiades:
The most accurate means of measuring star distances is that of
measuring the absolute parallax using the 186 million mile diameter of
the earth's orbit as the base line. Obviously the closer a star, the
more accurate the distance obtained. Such parallax measurements are
considered very accurate out to about 100 light years and usable (with
greatly increasing error) out to about 300 ly. Beyond 300 ly indirect
measurements need be used. The most accurate of the indirect measure
techniques involve the use of standard "candles" -objects of known
brightness. The most effective standard candles are the Cephid variable
stars. Other methods of indirect measurement include radial velocity
studies, the orbits of double stars and, in many cases, flat out
guessing! The best figures I can find for the distance of the Pleiades
seems to be around 410 ly. Alcyone, the brightest star in the group, is
listed as about 541 light years, but this apparent disparity only shows
the wide margins for error of any indirect measurement. Of course, who
knows what is actually being talked about when discussing the distance
to a star cluster. Is it the mean distance to all the stars, the
distance to the closest star or what? Determining which stars are evey
part of a given cluster is not an easy job!
Astronomer's lives would be so much simpler if these Pleiadians and
other "star travelers" would stop with all their banal pronouncements
about "peace and living together in harmony" (they ain't nothing new -
our own philosophers and teachers have been saying the same thing for
thousands of year) and start giving us basic scientific data.
The fact that out of all the thousands of so-called abductions,
channeled UFO information and the rest of the idle chatter there has
never been a new, VERIFIABLE piece of information must lead one to
doubt the veracity of these stories.
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* THE U.F.O. BBS -
http://www.ufobbs.com/ufo *
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