Planets have scientists buzzing
LONDON - A new wide-field survey of the sky has made its first major discovery - two planets orbiting far-distant stars.
Audiostream:
The SuperWasp project uses camera lenses and super-sensitive detectors to monitor stars for tiny dips in light that might betray a passing planet. The UK-led project identified a number of ”suspects” and then handed the data to a French observatory for checking. It used an instrument to analyse the light from the stars in detail and confirm the presence of the planets.
„To get these two we had to survey about 1.1 million stars and then go though several stages of filtering. It’s a bit like panning for gold”, Professor Andrew Collier Cameron from the University of St Andrews told.
The two extrasolar (outside our Solar System) planets, now known as Wasp-1b and Wasp-2b, are in the constellations of Andromeda and Delphinus. One is about 1,000 light-years from Earth; the other is about half that distance. They are what astronomers term ”hot Jupiters” - very large planets like the gas giants in our own Solar System but orbiting much closer in to their parent stars.
Whilst our Jupiter is almost 700 million km from the Sun and takes some 12 years to complete an orbit, these planets are just a few million km from their stars and take only a couple of days to complete an orbit. This makes them extremely hot. Indeed, scientists think that of the 200 or so extrasolar planets detected to date, these may be among the hottest of the lot. Wasp-1b’s temperature is estimated to be over 1,800C (3,300F).
Confirmation of the new finds came earlier this month when the team joined forces with the Swiss and French users of Sophie, a powerful new spectrograph sited at the Observatoire de Haute-Provence.
Sophie can detect if there is a slight change in a star’s velocity - the result of an (unseen) extrasolar planet’s gravity tugging the star in different directions as it makes an orbit. (RD)
Er zijn nog geen reacties geplaatst.