Quirks and Quarks

Planet With a Comet's Tail - Web Extra

A Neptune-sized planet orbiting a nearby star has a gaseous corona and tail.

A spectacular cloud of gas trails this planet around its star

Artist's impression of GJ 436b orbiting its star (Mark Garlick/University of Warwick)
A planet circling a nearby star has been found to have a huge gaseous corona and tail, similar to that of a comet.

The planet is a Neptune-sized gas giant orbiting very close to its red-dwarf star. Images taken by the Hubble Space Telescope showed that the planet is surrounded by, and trails, a massive cloud of hydrogen gas that is almost as large as the star itself.

Dr. Peter Wheatley, an associate professor of astronomy and astrophysics at the University of Warwick in England, says that the gas is being stripped from the atmosphere of the planet by X-rays from the star, at a rate of 1000 tonnes per second. While this seems a tremendous rate, the planet is large enough that it will not run out of gas during the lifetime of the star.

Related Links

Paper in Nature
Release from University of Warwick
Discovery news story 
- Popular Science story

(Note:  This is web-only interview that was not broadcast on radio)