CONTACT: Jacqueline Weaver 203-432-8555 #109

For Immediate Release: October 25, 2000

New Haven, Conn. — A new minor planet measuring about 400 miles in
diameter and located between Neptune and Pluto in the outer rim of the
solar system has been found by Yale astronomers.

Officially named 2000 EB173, the planet was discovered using a powerful
telescope located at the CIDA observatory in Merida, Venezuela. In
addition to Yale astronomers, the team included scientists from Indiana
University and Venezuela’s University of the Andes.

Because of its small size, one quarter the size of Pluto, the planet is
known as a “planetoid” or “plutino,” meaning “Little Pluto.”

“The significance of this finding? It’s just ‘Wow!’ After all these years
we can still find something new in our solar system,” said Professor
Charles Baltay, chairman of the Department of Physics at
Yale University and leader of the group that made the discovery. “Some of
it is luck. We looked in the right place. The other is the precision of
our instrumentation.”

Baltay said the telescope used in making the observation encompasses 250
square degrees of sky in one night, compared to one tenth of one square
degree with a more conventional telescope. The more powerful telescope is
equipped with a digital camera and photographs any changes in the sky.

“Most of the stars in the sky don’t change night to night, or even century
to century,” Baltay said. “However, planets in our solar system move very
rapidly.”

He said the members of the Quasar Equatorial Survey Team (QUEST) were
looking for quasars, supernovae and other variable objects when they found
the plutino. It was detected through a computer-aided search of thousands
of images recorded in a single six-hour period on the night of March 15.
The tiny, reddish planet was scarcely moving – just 10 arc seconds per
night – but was still fast enough to be recorded on the digital film.

Although many other objects have been recorded in the area known as the
“Kuiper Belt” just outside Pluto’s orbit, none were as large as the new
planetoid.

Baltay said it is customary that whoever finds a new object in the solar
system is allowed to name it, but only after it has circled the sun twice.
Unfortunately for Baltay, it will take 243 years for plutino to circle the
sun just once.

Other Yale researchers involved in the discovery were David Rabinowitz,
associate research scientists in the Department of Physics, Bradley
Schaefer, assistant professor of physics and astronomy, now at the University of
Texas at Austin, and Ignacio Ferrin of the University of the Andes.

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