Category: Extrasolar Planets

How’s the weather? Hot enough for you? Well, if you’re living on extrasolar planet HD 189733b, you’d really want to be anywhere else. That’s because the high noon temperatures reach 926 degrees C (1700 degrees F). How do we know what the weather’s like on this distant planet? Just thank Spitzer.

Astronomers working with NASA’s Spitzer Space Telescope have produced a rough map of the weather systems on HD 189733b. Over the course of 33 hours of observations, they gathered together more than 250,000 data points measuring the planet’s brightness. These data points were then mapped onto the planet, to show its global temperatures.

HD 189733b orbits its parent star at a distance of only 4.8 million km (3 million miles); it completes an orbit every 2.2 days. In terms of mass and size, it’s a little larger than Jupiter. This close proximity to its parent star puts it into the “Hot Jupiter” category, of extrasolar planets.

One interesting surprise: the hottest spot on the planet doesn’t directly face the star. Instead it’s offset about 30 degrees longitudinally. The researchers speculate that powerful weather systems redistribute the heat across the planet, and into these pockets of heat.

Original source: CfA News Release

The European Space Agency’s COROT planet hunting observatory turned up its first planet – a hot Jupiter – surprising its managers at how quickly it would yield scientific results. COROT was launched in December, 2006, and it has only been making scientific observations for 60 days when it found a planet.

COROT discovers planets using the transit technique. It measures the total light emitted by a star very carefully, watching for a slight dip as a planet passes in front. Once several of these dips have been observed, the planet’s size and orbital period can be calculated.

This newly discovered planet, now named COROT-Exo-1b, is a very hot gas giant, with roughly 1.78 times the mass of Jupiter. But unlike Jupiter, it orbits its parent star every 1.5 days. The planet is located about 1500 light-years from Earth in the constellation Monoceros.

Now that it’s in orbit, scientists are getting a better sense of COROT’s capabilities, and the news is really good. The recent observations show that it’s much more sensitive than they had expected. Planets as small as the Earth should be detectable. And here’s the great news, COROT should be able to detect the chemical composition of the planets’ atmospheres. In other words, COROT will be able to detect the presence of oxygen and other signatures for life on Earth-sized worlds surrounding other stars.

The discovery of life on another planet may just be around the corner.

Original Source: ESA News Release