Skip to main content

Astronomers spot an exoplanet creating spiral arms around its star

When you imagine a galaxy like our Milky Way, you’re probably picturing a swirl shape with arms reaching out from a central point. These spiral arms are a classic feature of many galaxies. Similar structures can be found around young stars which are surrounded by disks of matter from which planets form, called protoplanetary disks. Now, astronomers have discovered evidence that these structures could be created by recently formed exoplanets.

Astronomers used Large Binocular Telescope in Arizona to investigate a giant exoplanet named MWC 758c which seems to be forming the spiral arms around its host star. Located 500 light-years away, the star is just a few million years old, making it a baby in cosmic terms. “Our study puts forward a solid piece of evidence that these spiral arms are caused by giant planets,” said lead researcher Kevin Wagner of the University of Arizona in a statement. “And with the new James Webb Space Telescope, we will be able to further test and support this idea by searching for more planets like MWC 758c.”

The Large Binocular Telescope in Arizona. The LBTI instrument combines infrared light from both 8.4-meter mirrors to image planets and disks around young and nearby stars.
The Large Binocular Telescope in Arizona. The LBTI instrument combines infrared light from both 8.4-meter mirrors to image planets and disks around young and nearby stars. D. Steele/Large Binocular Telescope Observatory

The star still has its protoplanetary disk of dust and gas around it, making it comparable to the early stages of our own solar system. “I think of this system as an analogy for how our own solar system would have appeared less than 1% into its lifetime,” Wagner said. “Jupiter, being a giant planet, also likely interacted with and gravitationally sculpted our own disk billions of years ago, which eventually led to the formation of Earth.”

Recommended Videos

The spiral arms are formed in the protoplanetary disk by the gravity of large planets, as they attract nearby material to them. Astronomers had predicted this phenomenon but had not seen it in action until now, and by studying it they can learn about the formation of planetary systems.

“Spiral arms can provide feedback on the planet formation process itself,” Wagner said. “Our observation of this new planet further supports the idea that giant planets form early on, accreting mass from their birth environment, and then gravitationally alter the subsequent environment for other, smaller planets to form.”

The researchers plan to use the James Webb Space Telescope (JWST) to make further observations of the system, and particularly to learn why the giant planet is much redder than expected.

“Depending on the results that come from the JWST observations, we can begin to apply this newfound knowledge to other stellar systems,” Wagner said, “and that will allow us to make predictions about where other hidden planets might be lurking and will give us an idea as to what properties we should be looking for in order to detect them.”

The research is published in the journal Nature Astronomy.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Wild supersonic winds whip around this extreme exoplanet
This artist’s visualisation of WASP-127b, a giant gas planet located about 520 light-years from Earth, shows its newly discovered supersonic jet winds that move around the planet’s equator. With a speed of 9 km per second (33 000 km/h), this is the fastest jetstream of its kind ever measured in the Universe.

Planets outside our solar system can be wild, weird places. Astronomers have discovered exoplanets shaped like a rugby ball, or where it rains gems, or which have one hemisphere covered in lava. And now there's a new oddity to add to the catalog: a planet with winds that are faster than the speed of sound.

WASP-127b is a huge, puffy sphere which is one of the least dense planets ever discovered. It is larger than Jupiter, but has less than a fifth of Jupiter's mass, making it unlike anything in our solar system. And its oddity has made it a favorite target for study, with astronomers observing clouds there in 2022, making it one of the few detections of clouds on a planet outside our solar system.

Read more
Astronomers spot strange exoplanet with a tail 350,000 miles long
Artist's concept depicts new research that has expanded our understanding of exoplanet WASP-69 b's "tail."

Astronomers using the W. M. Keck Observatory in Hawaii have made a startling finding: a distant exoplanet with a tail hundreds of thousands of miles long. Planet WASP-69 b is located 164 light-years away, and as it orbit, it is followed by a stream of escaping gas that forms a tail -- making it look a little like a comet.

The planet is a type called a hot Jupiter, meaning it is a large gas giant that orbits very close to its star. So close, in fact, that a year there lasts less than four days and it has a blistering temperature of over 600 degrees Celsius.

Read more
Astronomers snap first up-close image of a star outside our galaxy
This image shows an artist’s reconstruction of the star WOH G64, the first star outside our galaxy to be imaged in close-up. It is located at a staggering distance of over 160 000 light-years away in the Large Magellanic Cloud. This artistic impression showcases its main features: an egg-shaped cocoon of dust surrounding the star and a ring or torus of dust. The existence and shape of the latter require more observations to be confirmed.

It's sometimes hard to grasp the scale of our universe, when even our own galaxy is so large and filled with billions of stars. But all of the stars that we have seen in detail are contained within the roughly 100,000 light-year span of our Milky Way galaxy. That is, until now, as astronomers recently observed a star outside of our galaxy up close for the first time.

The researchers looked at star WOH G64, located 160,000 light-years away, using the European Southern Observatory’s Very Large Telescope Interferometer. The image shows the main bulk of the star surrounded by a puffy cocoon of dust and gas.

Read more