Astronomy Now Home
Home Magazine Sky Chart Resources Store

On Sale Now!



The February 2012 issue of Astronomy Now is on sale 19 January!



Top Stories



Lunar tandem successfully enters orbit around the Moon
...Ringing in the new year with back-to-back successes, a second NASA science satellite slipped into orbit around the moon Sunday, one day after an identical spacecraft braked into the same polar orbit for a $496 million mission to map the moon's interior by precisely measuring how its gravity affects the trajectories of the twin spacecraft...
  READ MORE

Astronomy Now's year in space
...Pluto’s new moon, salty water on Mars, interstellar travel and black trees on a world with two suns; look back over the year as we count down the most read news stories of 2011...
  READ MORE

First “mini-Earth” discovered around Sun-like star
...A rocky exoplanet smaller than Earth, and its neighbouring Earth-sized world with a thick water-vapour atmosphere, have been detected around a Sun-like star already known to host three larger planets....
  READ MORE








Star caught
consuming planet

DR EMILY BALDWIN
ASTRONOMY NOW
Posted: 20 May 2010


Bookmark and Share

According to new data collected by Hubble's Cosmic Origins Spectrograph (COS), the hottest known exoplanet in the Galaxy, WASP-12b, may also be the shortest lived, for it is being mercilessly consumed by its host star.

Astronomers already knew that WASP-12b was an oddity, orbiting its star so tightly that its atmosphere is superheated to some 2,200 degrees Celsius and the whole planet is contorted into an elongated rugby ball shape. Its swollen atmosphere has ballooned to three times Jupiter's radius and is swirling catastrophically into the star such that it may only have 10 million years left before it is completely devoured.

Artist concept of WASP-12b spilling into its host star. Gravitational forces due to the planet's proximity to the star have stretched the planet into an egg shape. Image: NASA, ESA, G. Bacon (STScI) and C. Haswell (The Open University, UK).

The exchange of matter between two stars is not unusual, but this is the first time it has been seen so clearly for a planet. “We see a huge cloud of material around the planet which is escaping and will be captured by the star,” says team leader Carole Haswell of The Open University. “We have identified chemical elements never before seen on planets outside our own Solar System.”

WASP-12b was discovered in 2008 by the SuperWASP (Wide Area Search for Planets) automated survey that searches for tiny dips in a stars' brightness as a planet passes in front of it. WASP-12b is so close to its star that it completes one orbit in just 1.1 days.

The sensitivity of Hubble's new COS instrument permitted measurements of the star's light at ultraviolet wavelengths that revealed absorption lines from elements such as aluminium, tin and manganese that become more pronounced as the planet transits the star, meaning that the elements exist in the planet's atmosphere as well as the star's. Furthermore, the fact that COS could detect these features at all suggests that the planet's heated atmosphere is highly extended.

In addition, COS measurements enabled astronomers to produce a light curve to show precisely how much of the star's light is blocked out during a transit event, which can be translated into the planet's radius. The planet is 40 percent more massive than Jupiter and its exosphere is so deformed that its radius exceeds its Roche lobe – the region of space around the planet within which material is gravitationally bound, and beyond which can escape onto the star, which is exactly what the Hubble observations confirm.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

Infinity Rising
This special publication features the photography of British astro-imager Nik Szymanek and covers a range of photographic methods from basic to advanced. Beautiful pictures of the night sky can be obtained with a simple camera and tripod before tackling more difficult projects, such as guided astrophotography through the telescope and CCD imaging.
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

Starry Night
Explore the Universe with these new versions of the award-winning Starry Night Software. Available now from the Astronomy Now Store.
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

Exploring Mars
Astronomy Now is pleased to announce the publication of Exploring Mars. The very best images of Mars taken by orbiting spacecraft and NASA's Spirit and Opportunity rovers fill up the 98 glossy pages of this special edition!
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

Mars rover poster
This new poster features some of the best pictures from NASA's amazing Mars Exploration Rovers Spirit and Opportunity.
 U.K. STORE
 E.U. STORE
 U.S. & WORLDWIDE STORE

HOME | NEWS ARCHIVE | MAGAZINE | SOLAR SYSTEM | SKY CHART | RESOURCES | STORES | SPACEFLIGHT NOW

© 2010 Pole Star Publications Ltd.