Scorching Hot Jupiter Exoplanets Captured by NASA's Spitzer

Our galaxy teams with different planets, including the 800 exoplanets that circle stars other than our own sun. Now, NASA researchers have gotten a closer look at a particular "species" of these exoplanets known as hot Jupiters, or "roasters."

Using NASA's Spitzer Space Telescope, scientists are beginning to understand a little bit more about roasters, which are blistering hot gas giants like Jupiter that orbit closely to their stars. More specifically, they've been able to examine the planets' turbulent winds and the fact that they possess a wide range of climates; some are covered with a haze while others are clear.

These hot Jupiters have been known to exist for quite some time. In fact, the very first exoplanet that was discovered around a sun-like star was this particular species. Called 51 Pegasi b, the exoplanet was detected in 1995 by Swiss astronomers using the radial velocity technique. This particular method measures the "wobble" of a star created by the tug of a planet.

Now, researchers are using Spitzer to monitor these Jupiters as they orbit all the way around the star. This allows them to create global climate maps and reveal how the planets' atmospheres vary from their hot, sun-facing sides to their cooler, night sides.

In this latest study, researchers made the longest Spitzer observation yet of a hot Jupiter--about six days. The exoplanet, named HAT-P-2, crossed in front of its star, slipped behind it and appeared again on the other side over the course of the observations.

So what did the researchers find? They noticed that it took the exoplanet about a day to heat up as it approached the hottest part of its orbit, and then four or five days to cool down as it swung away. The planet also exhibited a temperature inversion, which is a hotter, upper layer of gas, when it was closest to its star. In addition, the carbon chemistry on the planet seemed to be behaving in unexpected ways.

"It's as if nature has given us a perfect lab experiment with this system," said Heather Knutson, co-author of the new paper describing the observations, in a news release. "Because the planet's distance to the sun changes, we can watch how fast it takes to heat up and cool down. It's as though we're turning the heat knob up on our planet and watching what happens."

The findings could allow scientists to better understand these large, scorching exoplanets and learn exactly how an orbit affects planets. Currently, research is ongoing as scientists parse through the data and learn exactly how these exoplanets behave.