Canada's Astronomers Doing Stellar Research

Canada's Astronomers Doing Stellar Research

CANADIANS ARE masters of the universe. Just look at the numbers. Sure, the U.S. leads the world in spending on space research, laying out roughly US$7 per American each year, while Britain, France and Germany budget between US$4 and US$5 for every citizen. Canada spends just US$1 per capita, less even than Australia. Yet by one important measure - the confidence of their peers - Canadian astronomers produce some of the best astrophysical science on the planet. Thomson Scientific, a Philadelphia-based information clearing house, reported Canadian scientists published 4,836 research papers on space in the past decade. Those studies in turn were referenced 76,921 times in other scientific papers, for an average citation rate of 15.91. U.S. scientists produced many more papers in total, but they were cited just 15.18 times - good, but only for second place. Canadian astronomers, says Thomson spokesman Rodney Yancey, "influence the field a great deal."

If one were to list Canada's 150 most cited scientists from the many different fields of study, about 15 would be astronomers, says Jaymie Matthews, associate professor of ASTRONOMY at the University of British Columbia. It's a remarkable feat given the relatively small size of the community. "I can assure you," says Matthews, "astronomers don't represent 10 per cent of the Canadian scientific population."

William Harris, a frequently cited astronomer at McMaster University in Hamilton, likens the Canadian success to a talented student making a movie with next to no money. The young director is forced to be innovative. And while limited means can draw the best out of people, it can also be a double-edged sword. The downside, says Matthews, is "now we're expected to pull this off every time on a shoestring budget."

Lack of funding has forced scientists to pick their projects wisely, observes Ray Carlberg, an astrophysics professor at the University of Toronto. "We can't do everything if we want to have impact," he says. "There are a million and one choices that you can make, and Canadian astronomers, as a group, clearly make some good ones."

In that group a number of academics stand out. Last year's most quoted paper - cited 1,058 times - mapped the radiological afterglow of the big bang, in the process helping confirm theories of how the universe came to be. It was written by 17 international scientists, among them Mark Halpern of the University of British Columbia. Another bright light is Peter Stetson, an astronomer at the Herzberg Institute of Astrophysics near Victoria: he is known for developing a key software program called DAOPHOT, the gold standard for analyzing star clusters. And Don VandenBerg at the University of Victoria is internationally acclaimed for his work on modelling stars of different size and composition. Other scientists employ VandenBerg's findings like a template, to gauge the age of stars.

For Canadians, it's a nice time to be stirring up some cosmic dust. The universe is a happening place. In 1998, scientists at the Lawrence Berkeley National Laboratory in California found that, contrary to earlier notions, the 13.7-billion-year-old universe isn't slowing but rather accelerating the expansion that began with the big bang. Why? Because of something called dark energy, a mysterious force that somehow causes stars and other cosmic entities to zoom apart faster than gravity should allow. Other discoveries have also changed our perception of the heavens. It was just over a decade ago when astronomers discovered the first planet to orbit a star other than our own sun. Today, almost 150 of these so-called exoplanets have been identified. In July, three U.S. researchers said they had confirmed a 10th planet in our solar system, out past Pluto and about 1.5 times its size.

At the turn of the 20th century, the Milky Way was considered the sum total of our universe. Canadians helped changed that. In the run-up to the First World War, the country's leaders had the foresight to build what was then the world's largest telescope. Located just outside Victoria on Little Saanich Mountain and still in operation, the 1.8-m wide telescope at the Dominion Astrophysical Observatory didn't hold the title long. It did, however, help the world better understand the size of the Milky Way. Today, we believe it contains at least 100 billion stars - and that there are more than 100 billion galaxies in the known universe.

In the 1960s, Canada debated where to invest next. Should we build a telescope at home or go international? The decision was to join a consortium with France and Hawaii and build an observatory on the summit of Hawaii's Mauna Kea. "We didn't have a lot to put on the table compared to the overall cost," recalls Matthews. "But we had expertise, so we had a contribution to the project far out of proportion to the money." (Since then, Canada has also entered into other multinational partnerships and built two larger 8-m telescopes, one at Mauna Kea and the other at an observatory on Cerro Pachón in the Chilean Andes.)

What Canada lacked until only recently was the ability to make observations from space. That changed with MOST, a suitcase-sized, $10-million rocket-borne telescope that was blasted into space in 2003. Backed by the CANADIAN SPACE AGENCY, MOST has already outlived its life expectancy and has another two, maybe three years to go, says Matthews, the project's mission scientist. MOST - for microvariability and oscillations of stars - is one of the first tools to allow Canadian scientists to home in on and study individual stars by measuring tiny light variations detectable only from space. In the lead up to the launch, researchers belatedly realized MOST could also be used to look at exoplanets. "We astronomers tend to be obsessed with size - we're always wanting to make bigger and bigger telescopes - while the MOST philosophy was that size didn't always matter," says Matthews. "But even we underestimated what we could do with a 15-cm telescope in orbit, with the right equipment attached to it."

As it did a century ago, Canada once again wants to build the world's largest telescope. Currently, the biggest are in the order of 8 to 10 m in diameter. However, there are now more than a dozen projects aimed at building a 30-m wide telescope. Canada, through the Association of Canadian Universities for Research in Astronomy, has teamed with two U.S. universities and another international agency to build what's being called the TMT (for the Thirty Metre Telescope). It's expected to cost nearly $1 billion, and Canada would have a 25-per-cent stake. The project is now in the design phase, and construction - which will include the painstaking assembly of more than 700 hexagonal mirrors - isn't expected to start before 2008. "This is no bathroom mirror," says Carlberg. "It's in the realm of big science."

Through the Canadian Space Agency, we are also a partner in the successor to NASA's revolutionary Hubble Space Telescope. Canada has a five-per-cent share in the James Webb Space Telescope, NASA's next-generation eye-in-the-sky that is due to launch in 2011 and will orbit about 1.5 million km above Earth. Canada's stake may not sound like much, says Harris, "but it's enough to give us a seat on the board of directors." It should also ensure Canada continues to get a big bang for its buck.

Maclean's September 5, 2005