Astrophysicist compiles 17-year timelapse of an alien world

You can view the ten-second timelapse showing Beta Pictoris b orbiting its star for 17 years via the embedded video below. During some parts of the video, the glare from Beta Pictoris b's host star is too strong, so Wang marked the location of the planet with an "x" so observers will still know where it is.

Wang is an assistant professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences and an expert in exoplanet imaging. He has also previously worked on a 12-year timelapse video of four exoplanets orbiting their star.

The term exoplanet refers to any planet outside our solar system. Beta Pictoris b is an enormous example of one of these alien worlds. It is roughly 10 times as far from its host star as the Earth is to the Sun.

Its host star, Beta Pictoris, is also 1.75 times as massive and 8.7 times more luminous than the Sun. Beta Pictoris is also relatively young, with estimates suggesting it is between 20 and 26 million years old.

Beta Pictoris' massive size and brightness meant that Beta Pictoris b was relatively easy to image when it was first discovered in 2003.

"It's extremely bright," Wang explained. "That's why it's one of the first exoplanets to ever be discovered and directly imaged. It's so big that it's at the boundary of a planet and a brown dwarf, which are more massive than planets."

How the exoplanet timelapse was assembled

Wang started compiling his timelapse of the Beta Pictoris system years ago. His first iteration showed five years of the exoplanet's journey.

For the new, longer version of the timelapse, Wang sought help from Malachi Noel, a student at New Trier High School in Winnetka, Illinois, who he met via the High School Students (REACH) program organized by the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).

Noel used AI-driven image-processing techniques to analyze archival imaging data from instruments at the Gemini Observatory and the European Southern Observatory.

Wang then used an algorithmic technique called motion interpolation to fill in any gaps so as to make a smooth video, as well as a technology called adaptive optics, to correct image blurring caused by Earth's atmosphere. He also utilized special instruments to reduce the glare from the host star.

"If we just combined the images, the video would look really jittery because we didn't have continuous viewing of the system every day for 17 years," Wang said. "The algorithm smooths out that jitter, so we can imagine how the planet would look if we did see it every day."

By providing a visual representation of a distant world far beyond our solar system, Wang hopes his work will inspire others to pursue science as a career or as a hobby.

"A lot of times, in science, we use abstract ideas or mathematical equations," he explained. "But something like a movie— that you can see with your own eyes — gives a visceral kind of appreciation for physics that you wouldn't gain from just looking at plots on a graph."