Skip to main content

This exoplanet has two suns – just like Tatooine

A team of astronomers has detected a “Tatooine-like” exoplanet that orbits two stars. A person living on the planet would see two suns in the sky, like Luke Skywalker’s home planet in Star Wars — but unfortunately, it’s a gas giant, so don’t make any plans to build a house there.

The planet, known as Kepler-16b, is located 245 light-years away and was detected using a ground-based telescope at the Observatoire de Haute-Provence in France. A planet orbiting two stars is technically known as a circumbinary planet, and these are rarely discovered. They are interesting puzzles as it’s not clear how such planets form. Typically, planets form from disks of matter around a single star, called protoplanetary disks, but this might not work in a system with two stars.

Artist's impression of Kepler-16b, which can be seen in the foreground.
Artist’s impression of Kepler-16b, the first planet known to definitively orbit two stars – what’s called a circumbinary planet. The planet, which can be seen in the foreground, was discovered by NASA’s Kepler mission. NASA/JPL-Caltech/T. Pyle

“Using this standard explanation it is difficult to understand how circumbinary planets can exist,” leader of the team, Amaury Triaud of the University of Birmingham, explained in a statement. “That’s because the presence of two stars interferes with the protoplanetary disc, and this prevents dust from agglomerating into planets, a process called accretion. The planet may have formed far from the two stars, where their influence is weaker, and then moved inwards in a process called disc-driven migration – or, alternatively, we may find we need to revise our understanding of the process of planetary accretion.”

Another notable feature of the planet is the way that it was detected. The planet was first discovered by the space-based telescope Kepler in 2011, but these researchers detected the planet using the radial velocity method, which used a ground-based telescope to look at the tiny variations in the star caused by the gravity of the planet orbiting around it. Detecting such planets from a ground-based telescope using this method is much cheaper than using space-based telescopes like Kepler, so it opens the door to discovering more planets like it in the future.

“Our discovery shows how ground-based telescopes remain entirely relevant to modern exoplanet research and can be used for exciting new projects,” said Dr. Isabelle Boisse of Aix-Marseille University. “Having shown we can detect Kepler-16b, we will now analyze data taken on many other binary star systems, and search for new circumbinary planets.”

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
SpaceX reportedly turns a profit after two annual losses
SpaceX's Falcon Heavy rocket heads to space on Tuesday, November 1, 2022.

SpaceX has turned a profit following two years of narrowing losses, according to documents seen by the Wall Street Journal.

The spaceflight company led by Elon Musk raked in revenue of $1.5 billion in the first quarter of this year, resulting in a profit of $55 million.

Read more
Wild ‘heartbreak’ star has waves three times the height of the sun
Artist conception of the system, where the smaller star induces breaking surface waves in the more massive companion.

Astronomers often share news about strange and exotic exoplanets, like one that is shaped like a football or another that has metallic rain. But far-off stars can be strange as well, as one recent piece of research points out. An enormous new type of star, which researchers are calling a "heartbreak" star, has gigantic waves on its surface that are three time the size of our sun.

The star, officially called MACHO 80.7443.1718, gives off regular pulses of brightness, making it similar to a known type of star called a heartbeat star. Stars like this are typically one of a pair, which orbit each other in an elongated, oval-shaped orbit. When the two stars come close to each other, their gravitational forces pull at each other, creating waves on their surfaces, similar to how the moon causes tides on Earth. But this particular star is an extreme version of the phenomenon, with brightness that varies by 200 times as much as a typical example.

Read more
Watch a video of an exoplanet orbiting its star — made from 17 years of observations
Artist’s impression of the planet Beta Pictoris b orbiting its star.

It's rare that we get to see exoplanets themselves. Most often, planets in other star systems are too small and too dim to be directly detected, so astronomers infer their presence based on their effects on their host stars. But occasionally, it is possible to image a star directly -- and recently, astronomers managed to create not only an image, but a video of an exoplanet orbiting its star.

17 years of real footage of an exoplanet (Beta Pic b)

Read more