Imagine being able to travel out of our solar system to visit new planets and see distant stars close up. No one knows if we’re ever going to get that far, but it looks like we’d have a pretty good map.
An international team of astronomers, including two local ones, has managed to find 10 new extra solar planets using two batteries of stargazing cameras and a technique that could help explain how planets form.
“We’re up to 15 planets, so we’ve had five previous discoveries,” said Rachel Street, a postdoctoral fellow at UCSB and at Las Cumbres Observatory Global Telescope Network (LCOGT), which is located in Goleta but called the Santa Barbara Group.
“The really unusual thing about these is that we’ve found 10 over the space of the last six months, so our planet detection rate has gone up dramatically.”
Street and LCOGT project scientist Tim Lister are part of a global team of scientists who are using telescopes to complement the planet-finding efforts of the high-powered SuperWASP (Wide Area Search for Planets) cameras. Team leader Don Pollaco, of Queen’s University, Belfast, Northern Ireland, announced the findings at a talk at the Royal Astronomical Society’s national astronomical meeting Wednesday.
The two batteries of SuperWASP cameras, located in Spain’s Canary Islands and also in South Africa, both watch for planetary transits, where a planet passes directly in front of a star and blocks out some of the star’s light. They can survey large areas of the sky at once, and astronomers, using the huge amount of data they receive from millions of stars, can check for these temporary changes in brightness.
“The reason that’s important is because it allows us to characterize these planets better than most of the planets that have been discovered so far,” Street said. “The more we can learn about the planets form, how they evolve, whether our own solar system is typical, or unique or special in any way, and so we learn more about planetary formation and our place in it.”
While there are any number of things that may cause a change in the brightness of a star, it’s up to scientists like Street and Lister to determine which stars to train their telescopes on. LCOGT uses robotically controlled telescopes in Arizona, Hawaii and Australia. Meanwhile, other telescopes such as the Nordic Optical Telescope in La Palma, Spain, the Swiss Euler Telescope in Chile and the Observatoire de Haute Provence in Southern France provide confirmation of the new discoveries.
The technique is a change in planet discovery from the gravitational technique, which focuses on watching the star as it is affected by the gravity of its orbiting planet. As slow as the gravitational technique is, however, it has been used to discover about 270 planets since the early 1990s.
The planets discovered by SuperWASP transit survey range from half the size of Jupiter, the largest planet in our solar system, to eight times Jupiter’s size. The planets closest to their stars are the most easy to detect, said Street. One planet they discovered is so close to its sun that a full orbit is just over one day and its daytime temperature could reach 2300 degrees Celsius (4,172 degrees Fahrenheit).
While finding an plotting out these newly discovered solar systems is enough of a task, for these astronomers it’s but one step in a far grander, and rather quixotic-sounding, venture.
“The more planets we detect, the better idea we’ll have about whether our particular system is unusual, and, of course, that feeds into the fact that one of our planets has life on it,” Street said. “Is life in any way unusual or are there specific circumstances that were somehow unusual as planet-forming goes? The only way to find that out is to look at lots of different planet systems.
“It could be that the circumstances that form habitable planets are quite common, which would be great, because there might be lots of habitable planets out there,” she said.
What they would do if they managed to find a planet that supports life as we know it is a story better left for another day, far into the future. But for the moment, the astronomers are only beginning to scratch the surface.
“To make a statistically significant sample we’re going to have to find probably thousands of theses sytems,” Street said. “This is just the tip of the iceberg.”