For the first time, UW astronomers have created a rough temperature map of a distant planet orbiting a sun-like star, using a process that may one day enable mapping of Earth-like planets in other solar systems.

Categorized as a gas giant, the planet is slightly larger than Jupiter and has a non-solid surface, giving the map cloud-top features.

The astronomical study used NASA's infrared Spitzer Space Telescope, which enabled the researchers to locate a bright, hot spot that has the highest temperature on the planet. This spot is known as HD189733b and is approximately 20 degrees of longitude away from the most intense region of light from the star.

"This provides us with really strong evidence that there are strong winds which transport the heat from the planet's spot closest to the sun-like star and then release it downstream at the point where it is hottest," said Eric Agol, assistant professor of astronomy, who co-authored the study with astronomy graduate student Nicolas Cowan.

The astronomers used the telescope's Infrared Array Camera, which made it easier to separate the planet's signal from that of the star, because it lessens the brightness difference between stars and planets, the researchers said. The scientists observed the planet for 33 hours, collecting more than a quarter million data points which they used to assemble a longitudinal map, measured by infrared strips running pole to pole. The strips were then assembled into an overall picture.

"First we observed the night side of the planet, and then the planet slowly became brighter as the day side turned toward us," Agol said. "From these observations, we realized that we should be able to create a heat map of the planet by looking at what the brightness should be at each slice of longitude."

The researchers acquired all information without directly viewing the planet, said Heather Knutson, chief author of the paper and a Harvard University graduate student.

"Before, it would have required a huge telescope to do this, but in this study we were able to create a rough map of this planet with our current technology, just by using dynamical measurements of how light and temperature changed with time," Knutson said.

The map may help astronomers learn moer about other astronomers.

"While we don't know much about many distant planets, by being able to map them out through models like this, we can begin to study their atmospheres," she said. "It's really cool to be able to map out a planet that's 60-something light-years away."

She added that in the future, astronomers in the field hope to examine other planets of similar size to Earth.

"I guess it all comes down to the whole curiosity surrounding a search for life outside our planet," Knutson said. "One of the things people talk about is looking for signatures of oxygen and ozone in the atmospheres of Earth-like planets. If they have similar levels to ours, it is very possible these planets could have bacteria or primitive organisms. It's exciting to think about."

Reach reporter Katie Stapleton-Paff at news@thedaily.washington.edu.