A new video released by Northwestern University shows four bright dots of light moving around a central black disc in concentric circles. The amazing footage is actually a planetary system and the four dots are exoplanets. Their star is located 133.3 light-years from Earth and is hidden by a dark disc. The orbital motions are depicted by the partial circles, which are time lapses assembled from 12 years of observations.
Jason Wang, an astronomer at Northwestern University, put together this never-seen-before time-lapse of the "family of four planets, each more massive than Jupiter, orbiting their star."
The astronomer said, "It's usually difficult to see planets in orbit. For example, it isn't apparent that Jupiter or Mars orbit our sun because we live in the same system and don't have a top-down view. Astronomical events either happen too quickly or too slowly to capture in a movie. But this video shows planets moving on a human time scale. I hope it enables people to enjoy something wondrous."
The star is HR 8799 and in 2008, the exoplanets orbiting it formed the first system that astronomers have ever observed up close. Although it appears to be a great distance away, HR8799 is regarded as being in our "solar neighbourhood." HR8799 is approximately five times brighter and one and a half times more massive than the sun, as per the statement by the University.
"There's nothing to be gained scientifically from watching the orbiting systems in a time-lapse video, but it helps others appreciate what we're studying," Mr Wang stated. "It can be difficult to explain the nuances of science with words. But showing science in action helps others understand its importance," he added.
Mr Wang utilised a technique known as "adaptive optics" to create the clip and removed visual blurring brought on by the Earth's atmosphere. In order to reduce the glare from the main star, he additionally used specialised equipment called a "coronagraph" and processing algorithms. Further, he smoothened the motion of the planets and filled in data gaps using a type of video processing. Otherwise, instead of revolving around in a smooth orbit, the planets would appear to leap.
