Solar System Look-Alike Found

A new solar system has been found amongst distant stars in the Milky Way.

Using a method that observes the bending of light by gravity, as described by Albert Einstein, astronomers in New Zealand, Poland, USA and elsewhere have identified a scaled-down version of our own solar system within the Milky Way galaxy, the first to be identified.

The results are published in this week’s issue of the prestigious journal Science.

When two stars align, the gravitational field of the nearer star can be used as a lens to magnify the more distant star. The method is particularly effective in identifying faint or dark objects, using any electromagnetic radiation emitted from the further object to view it. The technique was developed in part at The University of Auckland, by Associate Professor Phil Yock, Dr Ian Bond, now at Massey University, and Dr Nicholas Rattenbury, now at the University of Manchester, UK.

An alignment of two stars in the constellation of Sagittarius, catalogued as OGLE-2006-BLG-109, was identified by Polish astronomers, led by Professor Andrzej Udalski of Warsaw University, using a telescope based in Chile. Other astronomers globally continued to monitor the alignment. A total of 69 scientists in 11 countries provided data and contributed to the discovery, including Paul Tristram of the MOA collaboration at the Mt John Observatory, the first New Zealander to pick up on this event.

“It has been an exciting project, really highlighting the international cooperation possible when the scientific stakes are high,” says MOA collaborator Associate Professor Philip Yock of the Faculty of Science.

Dr Scott Gaudi and Professor Andrew Gould of Ohio State University and Associate Professor David Bennett of Notre Dame University carried out the task of collating and analysing the data from all the telescopes involved and are the lead authors of the Science article. The analysis revealed the nearer star was a red dwarf, a smaller and cooler version of our Sun, and that two giant planets somewhat smaller than our Jupiter and Saturn orbit it. The complete system could be likened to a half-size version of the Sun, Jupiter and Saturn, with the temperatures of the Jupiter and Saturn look-alikes being quite similar to those of our Jupiter and Saturn.

Other New Zealand astronomers involved include microFUN collaborators Dr Grant Christie at the Stardome Observatory and amateur astronomer Jennie McCormick at her Farm Cove observatory in Pakuranga; PLANET member Dr Michael Albrow of Canterbury University; and MOA members Dr Ian Bond (Massey), lead investigator for the project in New Zealand, Dr Winston Sweatman (Massey), Dr Denis Sullivan (Victoria University) and Professor John Hearnshaw (Canterbury).

MOA is a collaboration between Japan and New Zealand funded in New Zealand by a Marsden grant from the Royal Society of New Zealand.

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