This weird exoplanet is shaped like a rugby ball

By Georgina Torbet January 16, 2022

Exoplanets come in many sizes, and sometimes they also come in unusual shapes. The European Space Agency’s CHEOPS exoplanet-hunting telescope has discovered a planet the shape of a rugby ball, pulled into that form by extreme gravitational forces.

The planet, named WASP-103b and located in the constellation of Hercules, experiences epic tidal forces due to orbiting so close to its star, with a year that lasts just one day. The planet is big, at twice the size of Jupiter, and with one and a half times its mass. “Because of its great proximity to its star, we had already suspected that very large tides are caused on the planet. But, we had not yet been able to verify this,” explained study co-author Yann Alibert, professor of astrophysics at the University of Bern, in a statement.

Artist impression of planet WASP-103b and its host star. — Artist impression of planet WASP-103b and its host star: ESA’s exoplanet mission Cheops has revealed that an exoplanet orbiting its host star within a day has a deformed shape more like that of a rugby ball than a sphere. The planet, known as WASP-103b is located in the constellation of Hercules. ESA

Using CHEOPS, the team was able to verify the tidal deformation of the planet by looking at its transits. When the planet passes between its star and Earth, in an event called a transit, the team could measure the dip in brightness from the star and learn about the planet. “After observing several such so-called “transits”, we were able to measure the deformation. It’s incredible that we were able to do this — it’s the first time such an analysis has been done,” said co-author Babatunde Akinsanmi.

As well as measuring its odd shape, the researchers were also able to learn about the planet’s interior by seeing how it was deformed. “The resistance of a material to deformation depends on its composition,” explained Akinsanmi. “We can only see the tides on Earth in the oceans. The rocky part doesn’t move that much. Therefore, by measuring how much the planet is deformed, we can determine how much of it is made up of rock, gas, or water.”

The findings suggest that the planet is similar internally to Jupiter, though it is twice the size. The researchers therefore think the planet has been inflated, perhaps due to heating from the nearby star.

The research is published in the journal Astronomy & Astrophysics.

Editors' Recommendations

Topics

Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

Space

See the weather patterns on a wild, super hot exoplanet

This is an artist’s impression of the exoplanet WASP 121-b, also known as Tylos. The exoplanet’s appearance is based on Hubble data of the object. Using Hubble observations, another team of scientists had previously reported the detection of heavy metals such as magnesium and iron escaping from the upper atmosphere of the ultra-hot Jupiter exoplanet, marking it as the first of such detection. The exoplanet is orbiting dangerously close to its host star, roughly 2.6% of the distance between Earth and the Sun, placing it on the verge of being ripped apart by its host star's tidal forces. The powerful gravitational forces have altered the planet's shape.

When it comes to understanding exoplanets, or planets outside our solar system, the big challenge is in not only finding these planets, but also understanding what they are like. And one of the biggest factors that scientists are interested in is whether an exoplanet has an atmosphere and, if so, what it is composed of. But, just like with weather here on Earth, exoplanet atmospheres aren't static. So the Hubble Space Telescope was recently used for an intriguing observation -- comparing data from an exoplanet atmosphere that had previously been observed, to see how it changed over time.

Hubble looked at planet WASP-121 b, an extreme planet that is so close to its star that a year there lasts just 30 hours. Its surface temperatures are over 3,000 Kelvins, or 5,000 degrees Fahrenheit, which researchers predict would lead to some wild weather phenomena. As it is such an extreme planet, WASP-121 b is well-known and has been observed by Hubble several times over the years, beginning in 2016.

Space

Astronomers spot rare star system with six planets in geometric formation

Orbital geometry of HD110067: Tracing a link between two neighbour planets at regular time intervals along their orbits, creates a pattern unique to each couple. The six planets of the HD110067 system together create a mesmerising geometric pattern due to their resonance-chain.

Astronomers have discovered a rare star system in which six planets orbit around one star in an elaborate geometrical pattern due to a phenomenon called orbital resonance. Using both NASA's Transiting Exoplanet Survey Satellite (TESS) and the European Space Agency's (ESA) CHaracterising ExOPlanet Satellite (CHEOPS), the researchers have built up a picture of the beautiful, but complex HD110067 system, located 100 light-years away.

The six planets of the system orbit in a pattern whereby one planet completes three orbits while another does two, and one completes six orbits while another does one, and another does four orbits while another does three, and so one. The six planets form what is called a "resonant chain" where each is in resonance with the planets next to it.

Space

How astronomers used James Webb to detect methane in the atmosphere of an exoplanet

An artists rendering of a blue and white exoplanet known as WASP-80 b, set on a star-studded black background. Alternating horizontal layers of cloudy white, grey and blue cover the planets surface. To the right of the planet, a rendering of the chemical methane is depicted with four hydrogen atoms bonded to a central carbon atom, representing methane within the exoplanet's atmosphere. An artist’s rendering of the warm exoplanet WASP-80 b whose color may appear bluish to human eyes due to the lack of high-altitude clouds and the presence of atmospheric methane identified by NASA’s James Webb Space Telescope, similar to the planets Uranus and Neptune in our own solar system.

One of the amazing abilities of the James Webb Space Telescope is not just detecting the presence of far-off planets, but also being able to peer into their atmospheres to see what they are composed of. With previous telescopes, this was extremely difficult to do because they lacked the powerful instruments needed for this kind of analysis, but scientists using Webb recently announced they had made a rare detection of methane in an exoplanet atmosphere.

Scientists studied the planet WASP-80 b using Webb's NIRCam instrument, which is best known as a camera but also has a slitless spectroscopy mode which allows it to split incoming light into different wavelengths. By looking at which wavelengths are missing because they have been absorbed by the target, researchers can tell what an object -- in this case, a planetary atmosphere -- is composed of.