Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, November 30, 1995 TAG: 9511300075
SECTION: NATIONAL/INTERNATIONAL PAGE: A-7 EDITION: METRO
SOURCE: KATHY SAWYER THE WASHINGTON POST
DATELINE: WASHINGTON LENGTH: Medium
Astronomers have taken pictures of a ``super planet,'' a never-before-seen kind of object that looks like a hotter, denser version of the planet Jupiter, orbiting a nearby star only 19 light years from Earth just below the constellation Orion.
This is the most planet-like body, and also the faintest object of any kind, ever photographed around a star other than the sun, scientists said Wednesday in announcing the discovery. They said the images, along with an ``astonishing'' analysis of the object's chemical composition, will greatly speed the intensifying search for Earth-like planets around other stars.
In early 1994, astronomers reported the first irrefutable evidence of planets around a star outside the solar system and, earlier this year, confirmed a second planetary system. But in both cases, the observers used indirect methods - measuring wobbles caused by gravitational interactions - rather than direct visual images.
``A picture is worth a thousand papers, and a [chemical] spectrum is worth 10,000,'' said Shrinivas Kulkarni of the California Institute of Technology in Pasadena, a member of the observing team.
The new ``super Jupiter'' is too massive and hot to be classified as a planet, at least under the conventional definition, but it is much too small and cool to shine like a star, the researchers said. They hailed the discovery instead as the first confirmed sighting of a brown dwarf - a long-sought class of mysterious object that, in theory, is something between a star and a planet.
However, ``the difference between Jupiter and a brown dwarf is very slim,'' said scientist/astronaut Sam Durrance of Johns Hopkins University
The object has a mass estimated at 20 to 50 times that of Jupiter but is so dense that, like Jupiter, its diameter is only about 80,000 miles. It is in an orbit about as far from the star as Pluto is from the sun - at least 4 billion miles.
It glows a dim, dull red, at temperatures no more than 1,700 degrees Fahrenheit (Jupiter is about 261 degrees F), with about 1/250,000th the luminosity of the sun, the researchers said. And its methane-rich chemical signature is ``astonishingly like that of a gas giant planet'' such as Jupiter or Saturn, said Kulkarni.
The signature of the methane, which looks like a series of yellow ``Ls'' on a graph, produced gasps when shown to an audience of astronomers in Florence, Italy, recently, he said. Methane gas is not present in stars, but is abundant in Jupiter and other outer planets of our solar system.
The ``super planet'' was discovered at Mount Palomar, in California, and confirmed by NASA's Hubble Space Telescope in Earth orbit. The findings are reported in today's issue of the journal Nature and Friday's issue of Science.
by CNB