From a NASA press release this week

NASA’s Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify molecules in their atmospheres….

Spitzer, a space-based infrared telescope, obtained the detailed data, called spectra, for two different gas exoplanets. Called HD 209458b and HD 189733b, these so-called “hot Jupiters” are, like Jupiter, made of gas, but orbit much closer to their suns.

The data indicate the two planets are drier and cloudier than predicted. Theorists thought hot Jupiters would have lots of water in their atmospheres, but surprisingly none was found around HD 209458b and HD 189733b. According to astronomers, the water might be present but buried under a thick blanket of high, waterless clouds.

Those clouds might be filled with dust. One of the planets, HD 209458b, showed hints of tiny sand grains, called silicates, in its atmosphere. This could mean the planet’s skies are filled with high, dusty clouds unlike anything seen around planets in our own solar system…

The ‘More Info’ page on the press release links to two papers “A Spectrum of an Extrasolar Planet”
by L. Jeremy Richardson et.al.
and A Spitzer Spectrum of the Exoplanet HD 189733b by C. J. Grillmair et.al. apart from some podcasts.

And via BA Blog, we are reminded that “Twenty years ago, astronomers witnessed one of the brightest stellar explosions in more than 400 years. The titanic supernova, called SN 1987A, blazed with the power of 100 million suns for several months following its discovery on 23 Feb., 1987.” Of course, the article doesn’t quite spell it out that the neutrino detectors were telling us something interesting three hours before the explosion was seen ! (See this link too – via Backreaction blog .)

sn1987.jpg
‘Rings’ left by the Supernova Explosion

Advertisements