Exoplanet in motion: Astronomers snap images of alien world circling star 63 light yrs away (VIDEO)
While the ground-breaking photos of exoplanet Beta Pictoris b may not look like much, they were no easy feat, considering the orbiting world typically appears a million times fainter than its parent star.
The images – taken by a team of astronomers led by Maxwell Millar-Blanchaer of the University of Toronto – were made possible by the Gemini Planet Imaging (GPI) instrument on the Gemini South telescope in Chile.
Although the exoplanet is 63 light years away, GPI's optics system was able to sharpen the image of the target by canceling out distortion caused by Earth's atmosphere. It then used a filter called a coronagraph to block out starlight, revealing the subtle glow of orbiting planets.
“This is the first coherent animation of a set of observations that really packages up nicely,” Millar-Blanchaer said in a press release.
Taken between November 2013 and April 2015, the images captured 1.5 years of the exoplanet's 22-year orbital period.
First discovered in 2008, Beta Pictoris b is a gas giant which is 10 to 12 times the mass of Jupiter and has an orbit roughly the diameter of Saturn's orbit. It is part of a system of the star Beta Pictoris, which consists of comets, orbiting gas clouds, and a massive debris disc.
The researchers' observations, published in the Astrophysical Journal, include refinements to measurements of the exoplanet's orbit and the ring of material circling the star. The paper also concludes that the most accurate measurement of the mass of the star Beta Pictoris shows it is highly unlikely the exoplanet will pass directly between Earth and its parent star.
The images have also allowed the researchers to see both the disc and the planet at the same time, opening up the possibility for further research.
“With our combined knowledge of the disc and the planet we’re really able to get a sense of the planetary system’s architecture and how everything interacts,” Millar-Blanchaer said.
“It’s fortunate that we caught β Pic b (Beta Pictoris b) just as it was heading back – as seen from our vantage point – toward [star] β Pictoris,” said co-author Laurent Pueyo of the Space Telescope Science Institute. “This means we can make more observations before it gets too close to its parent star and that will allow us to measure its orbit even more precisely.”
Beta Pictoris b is just one of nearly 2,000 exoplanets that have been discovered by astronomers in the past two decades. Most have been detected with instruments such as the Kepler space telescope, which use the transit method of detection. That is, astronomers detect a faint drop in the star's brightness as an exoplanet transits or passes between Earth and the star, but do not see the exoplanet itself.