“We are getting our first good look at a completely alien world,” says Heather Knutson a graduate student here at Harvard who’s the lead author of a paper featuring the first map of an extrasolar planet , in the last issue of Nature.
“We felt a little like Galileo “ said she. More like Giordano Bruno burnt at the stake if the data are to be believed. It's a trifle warm on HD1897333b , as the Jupiter -sized planet orbits its fairly sun-like star at a distance of only 3 million miles, its sunshine is a thousand times more intense than Earth's
60 light-years from Earth in the constellation Vulpecula , HD1897333b's '" year " is only 2.2 days long. It is the closest known planet transiting between its star and the Earth.33 hours of observations by the Harvard-Smithsonian Center for Astrophysics, using the cold-mirror Spitzer Space Telescope' collected a quarter-million data sets at a wavelength of 8 microns. Although Spitzer's 32x32 pixel platinum silicide infrared detector array could not resolve the planet into a disk , a simple longitudinal map was made by measuring the rotating planet's brightness in pole-to-pole strips to assemble into a single picture.
And a pretty scary picture it is. This artist's impression of the square pixel map features a “hot spot” dwarfing the Great Red Spot on Jupiter. While Jupiter's Red Spot is only 30 degrees warmer than its frigid surroundings , HD 189733b's crimson hot spot is literally incandescent--973 K , which equals a scorching 1,700 degrees F.
There’s also a windburn problem. “ While Earth’s jet stream blows at around 200 miles per hour" says co-author David Charbonneau ," the jet stream on HD 189733b may blow as fast as 6,000 miles per hour.” He notes that models indicate that without the high Mach number winds , the planet's dark side would freeze. The Spitzer radiometer instead recorded a maximum temperature difference of about 500 degrees F , so temperatures on the night side linger in the balmy 1,200's. This is positively tepid compared to a planet being published in the latest issue of Nature.
Mad dogs and Englishmen would simply vaporize if they went out in the noonday sun on HD 149026b. At 4,000 Fahrenheit , only refractory oxide particles like TiO and molten silicate aerosols are thought to comprise the clouds in its hellish sky.