[Archport] Fwd: Long Lost Star Catalog Found in Plain Sight

[Graca Cravinho <graca@hermite.cii.fc.ul.pt>]

Title: Fwd: Long Lost Star Catalog Found in Plain Sight

> Long Lost Star Catalog Found in Plain
> Sight
> http://www.space.com/scienceastronomy/hipparchus_catalogue_050124.html
>
> By Bjorn Carey
> Staff Writer
> posted: 24 January, 2005
> 7:00 a.m. ET
>
> The long lost star catalog of Hipparchus has been under our noses -
> or, more accurately, slightly above them - for more than 1,800
> years.
>
> Sitting atop the broad shoulders of a seven-foot statue known as the
> Farnese Atlas is a sky globe depicting the nighttime sky. Scientists
> have been able to match the constellations shown on the globe with
> descriptions from Hipparchus's only surviving work,
> Commentaries, and have concluded that this is a marble copy of his
> star catalog.
>
> Hipparchus, who was Greek, was one of the greatest of the ancient
> astronomers and did his most important work between 140-125 BC. He
> calculated the length of the year to within six and a half minutes,
> developed a scale to rate the brightness of stars, was the first to
> record a nova, theorized on the motions of the Sun and Moon, provided
> high quality planetary observations and created the first ever catalog
> of 1,000 stars.
>
> Perhaps his most important observation, and the one that provided the
> key to determining the Atlas held his catalog, was precession.
> Precession is the wobbling of Earth on its axis, like a spinning top
> as it slows down, over long periods of time. This wobbling is on a
> 26,000 year cycle, and causes the stars to appear to move across the
> sky. For example, Polaris, the North Star, is currently above the
> North Pole, but it has not always been so and will not be in the
> future.
>
> Bradley Schafer of Louisiana State University, Baton Rouge combined
> data from the precession cycles with measurements he took of 70
> positions on the globe and used a mathematical model to determine what
> point in time the Atlas's sky globe represents. Schafer determined
> that the best date for the original observations was 125 BC, with a
> normal margin of error of ± 55 years.
>
> The date of 125 BC immediately suggests that this is the lost catalog
> of Hipparchus, who created his star catalog in 129 BC. The 125 BC date
> also eliminates all previously proposed candidates for this star
> catalog. The works of Aratus (275 BC), Eudoxus (366 BC), and the
> Assyrian observer (1130 BC),are all too early, while Ptolemy's work in
> 128 AD is too late to match up to this star catalog.
>
> Providing more evidence that the constellation figures on the Farnese
> Atlas were based on a star catalog is that the accuracy is within 3.5
> degrees - which would not be possible based on the simple verbal
> descriptions provided by Aratus or Eudoxus, which only have accuracy
> of about 8 degrees.
>
> Additionally, the Atlas sky globe shares no differences and many
> unique similarities with the constellations Hipparchus described in
> Commentaries.
>
> The Farnese Atlas, dating to 150 AD, is a well known Roman copy of a
> Greek statue, and depicts 41 constellations, the celestial equator,
> tropics, and ecliptic. It is currently in the Farnese Collection in
> the National Archaeological Museum in Naples, Italy. Atlas was
> sentenced by Zeus to hold up the sky - this Atlas holds the nighttime
> sky.
> "Perhaps the most fascinating part of the
> discovery is simply that we have recovered one of the most famous
> known examples of 'lost ancient wisdom,'" Schafer
> said.
>

050124-HipparchusStaCatalog.jpg
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