UC Santa Cruz Astronomers Document Distant Planet's Exploding Skies

UC Santa Cruz astronomers document distant planet's exploding skies

By Michael Torrice - Sentinel correspondent
Posted: 01/28/2009 04:50:38 PM PST


Every 111 days, a distant planet called HD 80606b has its skies explode with swirling storms, say UC Santa Cruz astronomers.

The UCSC scientists produced their extraterrestrial weather report after watching the planet heat up as it passed by a nearby star.

"The temperature of the planet's atmosphere increased rapidly as it passed close to the star," said Gregory Laughlin, a professor of astronomy and astrophysics at UCSC. "The whole planet was glowing red-hot."

By studying weather on far-away planets, scientists hope to improve their understanding of the physics of weather on Earth, Laughlin says.

"It's useful to compare the predictable, sedate weather on Earth to the wildly changing weather on other planets," Laughlin said.

HD 80606b circles a star 200 light years, or over one quadrillion miles, from Earth. Like Jupiter, the planet is a gas giant 10 times larger than Earth.

Laughlin and his collaborators decided to study the planet because of its odd orbit. For one day of its 111-day orbit, the planet swings within three million miles of the star, closer than Mercury's distance to the sun.

"The planet makes a death-defying plunge toward the star and gets a heavy dose of heating," Laughlin said.

To measure the heating, the UCSC astronomers watched the infrared light streaming from the planet using NASA's Spitzer Space Telescope. In the cover story of Wednesday's issue of Nature, they report the temperature of the planet's atmosphere jumped from 980 degrees to 2,240 degrees after it passed by the star.

Jonathan Langton, a postdoctoral researcher at UCSC and coauthor of the study, used the Spitzer telescope data to create a computer simulation of weather on the planet.

In the simulations, weather fronts erupt on the hot side of the planet with wind speeds exceeding 10,000 mph. The fronts then race toward the planet's dark side like shockwaves and develop into violent storms that eventually subside as the planet travels away from the star and cools.
"Even though it's a beautiful thing to observe, it would be a dramatically unpleasant place to be," Laughlin said.

Amateur astronomers may have a chance to glimpse HD 80606b in action Feb. 14. There is a 15 percent chance the planet will pass in front of its partner star causing the star's light to dim briefly, Laughlin said.