The European Southern Observatory (ESO) has released a rather incredible series of images showing the orbit of a planet around a distant star.
Captured by the ESO’s Very Large Telescope (VLT), the images show the exoplanet Beta Pictoris b making its way around its host star, 63 light-years from Earth. The planet orbits at a distance of about 1.3 billion kilometers (800 million miles), slightly closer than Saturn orbits our own Sun.
Beta Pictoris b is about 1.5 times the size of Jupiter and about 13 times more massive. It takes about 20 years to orbit its star, and at the moment it’s the only planet we know of in the Beta Pictoris system.
Despite the large distance of its orbit, this is still the closest planet we’ve ever directly imaged orbiting another star. And the planet is thought to be extremely hot, with an average temperature of about 1,500°C (2,700°F).
These images were captured by the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on the VLT. Direct imaging of planets is extremely difficult, not least because of the great distances involved, but also the brightness of the star. While these are not the first such images, they show incredible clarity in an exoplanet's orbit.
“These images are a remarkable achievement, heralding a new era in one of the most exciting and challenging areas of astronomy – discovering and characterising exoplanets,” said the ESO.
The ESO also released a short time-lapse video of the images. ESO/Lagrange/SPHERE consortium
While SPHERE is designed for this method, it has its limitations. The planet disappeared from view as it passed close to its star from our point of view, moving out of sight in November 2016. In September 2018, however, it re-emerged, letting us watch the planet continue its orbit around the star.
These images also highlight just how far we’ve come in exoplanet research. The first planets outside our Solar System were not discovered until 1992, and the vast majority are found via the transit method – watching the planet eclipse its star from our point of view – or the radial velocity method, noticing the wobble in a star from a planet’s orbit.
Getting a direct image of a planet like this is pretty incredible. And there are efforts underway to take even more images of such worlds, including the closest known exoplanet to Earth, Proxima b. For now, wave hello to our Jupiter-like friend Beta Pictoris b.