Kiwi astronomers find new planet

Life in space discovery closer as Kiwi astronomers find new planet

New Zealand researchers from Auckland, Canterbury, Massey and Victoria Universities were part of a 12 country study that has discovered the first new planet from outside our solar system that resembles the planet Neptune.

The multi-national team’s findings will be published this week in leading international science journal Nature.

To find the planet the researchers used a technique called ‘gravitational microlensing’ which uses the gravitational fields of stars as huge, naturally occurring lenses. This method was originally proposed by Einstein, but he thought that gravitational lenses would be too rare to be of practical value.

Associate Professor Phillip Yock from The University of Auckland’s Faculty of Science says the latest find brings the goal of locating a habitable planet in the Milky Way closer.

“Previous planetary finds using gravitational microlensing were of giant, gaseous planets similar to Jupiter, that presumably do not support life. The new planet is of a similar size to Neptune or Uranus which have cores composed of rock and ice and outer layers of hydrogen and helium.

“It orbits a cool, ‘red dwarf’ star at a distance about three times the distance between the Earth and the Sun. Its temperature is about -220 degrees, too cold to sustain life. Previous Neptune-like planets were found at very small distances from their parent stars, and are too hot to sustain life. The new finding brackets the region of habitability.”

Associate Professor Yock who works in the Science Faculty’s Department of Physics says the future prospects for this technique are excellent.

“Planets as small as Earth can be found using the gravitational microlensing technique and it is only a matter of time before one is found. No other technique presently in use has this sensitivity, although space missions are being planned with this goal.”

New Zealanders contributed in several ways to the latest find. Dr Michael Albrow and Dr Karen Pollard of the University of Canterbury are members of a large microlensing group known as PLANET/Robonet which gained the most data on the new planet. This group operates a network of telescopes in Australia, South Africa, Chile and Hawaii. Dr Pascal Fouque first noted the planetary signal from Chile. This was confirmed by Dr Andrew Williams from Perth.

A Polish/US group called OGLE that is based in Chile found the gravitational microlensing event which enabled the planet to be found and they also obtained data on the planet from their routine observations.

The NZ/Japan MOA group that is based in New Zealand also obtained data on the planet as part of their routine observations with the new Japanese supplied telescope at the Mt John Observatory in Canterbury. The MOA group currently includes Dr Ian Bond of Massey University, Professor John Hearnshaw of Canterbury University, Associate Professor Denis Sullivan of Victoria University and Associate Professor Philip Yock of The University of Auckland.

Another international group known as MicroFUN is heavily involved in gravitational microlensing. They operate a network of telescopes, including two in Auckland, but unfortunately they did not observe the microlensing event in which the new planet was found.

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