A team of Canadian astronomers has given us our best view yet of an exoplanet orbiting its star 60 light years away.
A series of images captured between November 2013 to April 2015 shows the exoplanet β Pic b as it moves through 18 months of its 22-year orbit.
The images were taken with the Gemini Planet Imager (GPI) (see below) on the Gemini South telescope in Chile.
In the video above, the star is at the centre of the left-hand edge of the frame, hidden by the Gemini Planet Imager’s coronagraph – a special telescope that can view things close to the Sun or a star.
In the video, the planet is closer to the Earth than the star. The Dunlap Institute at the University of Toronto explains the system.
First discovered in 2008, β Pic b is a gas giant planet 10 to 12 times the mass of Jupiter, with an orbit roughly the diameter of Saturn’s. It is part of the dynamic and complex system of the star β Pictoris which lies over 60 light-years from Earth. The system includes comets, orbiting gas clouds, and an enormous debris disk that in our Solar System would extend from Neptune’s orbit to nearly two thousand times the Sun/Earth distance.
Maxwell Millar-Blanchaer, a PhD-candidate in the Department of Astronomy & Astrophysics, University of Toronto, is lead author of a paper describing observations of the β Pictoris system published last week in the Astrophysical Journal.
“The images in the series represent the most accurate measurements of the planet’s position ever made,” says Millar-Blanchaer.
“In addition, with GPI, we’re able to see both the disc and the planet at the exact same time. 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.”
The paper includes refinements to measurements of the exoplanet’s orbit and the ring of material circling the star which shed light on the dynamic relationship between the two. It also includes the most accurate measurement of the mass of β Pictoris to date and shows it is very unlikely that β Pic b will pass directly between us and its parent star.
Astronomers have discovered nearly 2,000 exoplanets in the past two decades but most have been detected with instruments — like the Kepler space telescope — that use the transit method of detection: astronomers detect a faint drop in a star’s brightness as an exoplanet transits or passes between us and the star, but do not see the exoplanet itself.