Original From: SCOTT HAGIE
Date/Number: 02/27/94 - 0000062
On: MERCOPUS - 0724 - Astronomy-IN
I pulled this off the Internet, and found it VERY interesting.
NEW YORK (AP) -- As Archimedes said, Eureka! A scientist says
he's confirmed the existence of two planets orbiting a dense star
in the Milky Way Galaxy. They would be the first known planets
outside our own solar system.
``The thing, to me at least, is a clear-cut case,'' Alexander
Wolszczan of Pennsylvania State University said Friday. Other
scientists also called the new data convincing.
In 1992, Wolszczan and a colleague said they had found evidence
that at least two planets were orbiting an extremely dense star
called a pulsar about 1,300 light-years from Earth, in the
direction of the constellation Virgo.
A light-year is the distance light travels in one year, about
5.9 trillion miles.
One planet appeared to contain 2.8 times the mass of the Earth
and orbit the pulsar every 98.2 days, at about half the distance
between the Earth and sun. The other planet, with at least 3.4
times Earth's mass, appeared to orbit every 66.6 days at just over
one-third the distance between the Earth and sun.
The planets have not been seen directly.
But the pulsar sends energy pulses toward Earth, and the
evidence for the planets lay in irregularities in the pattern of
those pulses. Those irregularities appeared to be caused by the
pulsar's being pulled to and fro by the gravity of orbiting
planets, the scientists said.
Wolszczan had said more study of the irregularities should show
that the planets are tugging gravitationally on each other and so
altering their orbits.
Friday, he said such evidence had been found and it ``confirms
that what we see are planet-sized objects.''
Shri Kulkarni, an astronomy professor at the California
Institute of Technology in Pasadena, called the new findings
scientifically convincing and a triumph for the proposal that the
``We know absolutely for sure now that there are planets
there,'' said Frederic Rasio, a theoretical astrophysicist at the
Institute for Advanced Study in Princeton, N.J.
Besides the two planets detected originally, the data reveals a
moon-sized object orbiting nearer the pulsar, and there may be
still more orbiting objects, Wolszczan said. ``It sort of looks
like a full-blown planetary system around that star,'' he said.
There had been indications of a third planet orbiting outside
the other two, but that turned out not to be true, Wolszczan said.
Wolszczan announced the new data at a meeting earlier this year.
His presentation is mentioned in an account of the meeting in the
current issue of the journal Nature.