Feeds

Astronomers spy fifth planet orbiting nearby star

Largest extrasolar system to date

Build a business case: developing custom apps

Astronomers have spotted a fifth planet orbiting 55 Cancri, making the (relatively) nearby star the centre of the most populous extrasolar system to date, New Scientist reports.

55 Cancri lies 41 light years from Earth, and is "slightly cooler and dimmer than our own Sun". It was already known to boast four planets, three giants orbiting closer than Mercury is to the Sun, and a fourth at roughly Jupiter's distance from the Sun, but four times as massive as the former.

The first four planets were identified using the radial-velocity method, or "the way their gravity tugs on the parent star". Researchers led by Debra Fischer of San Francisco State University and Geoff Marcy of the University of California in Berkeley, used the same technique to pinpoint the fifth, which lies between the hot inner trio and the distant world.

The new planet has been dubbed 55 Cancri f, and "appears to be a gas giant like Saturn". Significantly, it orbits 55 Cancri at a distance of 117 million kilometres, "about eight per cent farther than Venus is from our Sun", which means it's in the possible liquid water zone.

Sadly, the planet itself "probably does not boast the right conditions for life" since its mass is between that of Neptune and Saturn, "suggesting it has a gas-rich composition that is unfavourable for life as we know it".

Fischer explained: "We can only imagine that it might look something like a beefy Neptune-like planet or perhaps a Saturn-like planet with rings and moons around it."

She then postulated: "The gas-giant planets in our solar system all have large moons. If there is a moon orbiting this new, massive planet, it might have pools of liquid water on a rocky surface."

Which means, of course, the possibility of life. However, Marcy cautioned that "such a moon would need to be at least as massive as Mars in order to have enough gravity to hang onto its water over the long term... and none of the moons in our solar system are that heavy."

He concluded: "We have no evidence of any moon at all nor rings around this planet."

Still, hopes springs eternal, and Jonathan Lunine of the University of Arizona in Tucson, told New Scientist there's a sizeable and apparently planet-free "gap" between 55 Cancri's latest family member and the most distant brother.

He asked provocatively: "Is there perhaps a much smaller, terrestrial-sized planet lurking in that gap – one that might be habitable?" ®

The Essential Guide to IT Transformation

More from The Register

next story
Just TWO climate committee MPs contradict IPCC: The two with SCIENCE degrees
'Greenhouse effect is real, but as for the rest of it ...'
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
Flamewars in SPAAACE: cooler fires hint at energy efficiency
Experiment aboard ISS shows we should all chill out for cleaner engines
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
NASA Mars rover FINALLY equals 1973 Soviet benchmark
Yet to surpass ancient Greek one, however
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.