Newsgroup: it.scienza.astronomia
Titolo: scoperto il 10° pianeta ? (inglese)

Da Internet:
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05 Dec 2000 02:46 GMT (Reuters)
PHOENIX (Reuters) - A University of Arizona astronomer has found an object
in the outer reaches of the solar system that could be the second brightest
and largest so-called "minor planet" in space, researchers said on Monday.
Dubbed 2000 WR106, the large object visually plucked from the sky last week
by astronomer Robert McMillan appears only to be outdone by Pluto when it
comes to such objects located beyond Neptune's orbit, researchers said.
The discovery, spotted in a crowded star field in the northern Milky Way, is
one-fourth to one-half the size of Pluto. It measures roughly 330 miles to
750 miles in diameter and is 43 times further from the sun than earth is.
It is believed to be bigger than Ceres, the largest known asteroid.
"I knew it had the chance to be very special when I saw it," said McMillan,
principal investigator for the Spacewatch Project, a 20-year-program he
co-founded that studies the solar system. "It's pretty gratifying to find
something like this after all these years."
Such "minor planets" are classified by researchers in the field as
Trans-Neptunian Objects, items that stretch beyond that planet. There have
been 346 cataloged since the effort began in 1992, but few like 2000 WR106.
"The brighter the object, usually the bigger it is," said Brian Marsden,
director of the International Astronomical Union's Minor Planet Center in
Cambridge, Mass. "If it's bright, it's big in this game. That's a good rule
of thumb."
Marsden said the discovery may be an important step toward better
understanding and helping chart the blueprint for the vastness of space.
It also could mean that there are other large objects to be found -- perhaps
even Pluto-sized objects -- in the solar system in the years to come.
McMillan said he first saw the slow-moving object on Nov. 28 while glancing
at the computer screen from real-time images captured from a telescope on
Kitt Peak, near Tucson, Ariz. It was not detected by computer software.
He bounced from frame to frame until he was sure he may have seen something.
McMillan believes the bright object may have escaped astronomer's eyes
because they do not tend to look in crowded places, preferring to search in
better conditions.
"It's really like looking for lost keys under the street light," he said.
"It's easier to look in places that are clearer, where things are more
easily found."
The object was confirmed with 12 sightings over the next three days by
McMillan and astronomer Jeffrey Larsen and reported to the planet center.
McMillan believes it will take up to two years of efforts by other
researchers to determine the complete picture for the object known as 2000
WR106.
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Saluti.

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E':
max = naviga.naviga
Saluti \ scusate.

 Saluti \ scusate.
Non ho capito bene il senso di questa precisazione... ma mi sa tanto
che questo "pianeta X" non è il pianeta X, ma sempre e soltanto il
membro della fascia di Kruiper segnalato da Albino Carbognani
in un precedente post "2000 WR106".
Ciao
-- 
Lorenzo Trumino - hamlet_AT_inwind.it
__________________________________________
Gruppo Astrofili William Herschel - Torino
http://www.infinito.it/utenti/gaw.herschel
mailto: 
gaw.herschel_AT_infinito.it
_________________________
Change _AT_ in @ to reply

 in un precedente post "2000 WR106".
Infatti e' proprio cosi'. Immaginando che si sarebbe cominciato a parlare
del pianeta X (visto il limite superiore del raggio), nel mio e-mail di
ieri su 2000 WR106 avevo specificato:
<<Va sottolineato che non si tratta del pianeta X, ma di un membro
maggiore della fascia di asteroidi esterna (la fascia di Kuiper
appunto).>>
Ciao
Albino