Astronomical first: Hubble sees an exosolar planet!

Stephen Withers
Friday, 14 November 2008 09:35

Science - Space

For the first time, astronomers have directly observed a planet orbiting a star other than our own Sun. The historic image was captured by the Hubble Space Telescope.

Previously, exosolar planets have been detected by looking for stars that appear to wobble in the sky or by detecting a Doppler shift as they move fractionally towards and away from us. Either way, the changes are incredibly small.

But now astronomers have been able to photograph a planet orbiting the star Fomalhaut by using the Hubble Space Telescope.

Fomalhaut is a bright star in the southern sky, and at 25 light years distance is a relatively near neighbour.

Astronomers have been studying Fomalhaut for around 25 years since infrared images indicated a large amount of dust was present around the star.

Subsequent work determined that it was surrounded by a ring of debris. Hubble observations showed the ring had a sharp inner edge, suggesting that a planet had swept up any material closer to the star.

They also showed that the ring is offset from the star, and it seemed likely that this was caused by the gravitational field of a planet pulling the ring off centre.

So what name has been given to the planet? Something exotic, perhaps? Find out on page 2.