Skip to main content
  1. Home
  2. Space
  3. News

Astronomers discover extremely hot exoplanet with ‘lava hemisphere’

By

Astronomers have discovered an Earth-sized exoplanet with an unusually extreme climate where one half of the planet is thought to be covered in lava. The planet HD 63433 d is tidally locked, meaning one side of it always faces its star while the other half always faces out into space, creating a huge difference in temperatures between the planet’s two faces.

Like Kepler-10 b, illustrated above, the exoplanet HD 63433 d is a small, rocky planet in a tight orbit of its star. HD 63433 d is the smallest confirmed exoplanet younger than 500 million years old. It's also the closest discovered Earth-sized planet this young, at about 400 million years old.
Like Kepler-10 b, illustrated above, the exoplanet HD 63433 d is a small, rocky planet in a tight orbit of its star. HD 63433 d is the smallest confirmed exoplanet younger than 500 million years old.  NASA/Ames/JPL-Caltech/T. Pyle

NASA’s TESS (Transiting Exoplanet Survey Satellite) discovered that the planet HD 63433 d is about the size of Earth at 1.1 times the diameter of our planet, and that the star it orbits is similar to our sun, with 91% of the sun’s size and 99% of its mass. But what makes this exoplanet so different from Earth is its orbit, which is extremely close to its star. It completes an orbit of its star in just 4.2 days, making it eight times closer to its star than Mercury is to the sun.

Recommended Videos

As it is so close, it has tremendously high surface temperatures that can reach up to 2,294 degrees Fahrenheit (1,257 degrees Celsius) on the side facing the star. This is so hot that it has likely burned away any atmosphere that might have formed. In fact, the entire side facing the sun, called the dayside, could be a “lava hemisphere.”

Please enable Javascript to view this content

The system that the planet is located in is also different from our solar system in that it is around 10 times younger. The planet itself is only 400 million years old. The system has two other planets as well, HD 63433 b and c, which are both larger at around 5 times 7 times the mass of Earth, respectively. They also orbit slightly further out, with orbits of 7 days and 20 days, respectively.

Related

The new planet was discovered using TESS, which spots exoplanets by looking at their host stars. As planets outside our solar system are much smaller and dimmer than stars, they are very difficult to spot directly. So TESS uses a technique called the transit method, which observes a host star and looks for a small dip in its brightness that happens when a planet passes in front of it. By observing how often these dips in brightness occur and for how long they last, scientists can learn about the planets which must be causing them.

The research is published in The Astronomical Journal.

Editors’ Recommendations

Topics
Georgina Torbet
Georgina Torbet
Space Writer
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
James Webb observes extremely hot exoplanet with 5,000 mph winds
This artist’s concept shows what the hot gas-giant exoplanet WASP-43 b could look like. WASP-43 b is a Jupiter-sized planet circling a star roughly 280 light-years away, in the constellation Sextans. The planet orbits at a distance of about 1.3 million miles (0.014 astronomical units, or AU), completing one circuit in about 19.5 hours. Because it is so close to its star, WASP-43 b is probably tidally locked: its rotation rate and orbital period are the same, such that one side faces the star at all times.

Astronomers using the James Webb Space Telescope have modeled the weather on a distant exoplanet, revealing winds whipping around the planet at speeds of 5,000 miles per hour.

Researchers looked at exoplanet WASP-43 b, located 280 light-years away. It is a type of exoplanet called a hot Jupiter that is a similar size and mass to Jupiter, but orbits much closer to its star at just 1.3 million miles away, far closer than Mercury is to the sun. It is so close to its star that gravity holds it in place, with one side always facing the star and the other always facing out into space, so that one side (called the dayside) is burning hot and the other side (called the nightside) is much cooler. This temperature difference creates epic winds that whip around the planet's equator.

Read more
First indications of a rare, rainbow ‘glory effect’ on hellish exoplanet
For the first time, potential signs of the rainbow-like ‘glory effect’ have been detected on a planet outside our Solar System. Glory are colourful concentric rings of light that occur only under peculiar conditions. Data from ESA’s sensitive Characterising ExOplanet Satellite, Cheops, along with several other ESA and NASA missions, suggest this delicate phenomenon is beaming straight at Earth from the hellish atmosphere of ultra-hot gas giant WASP-76b, 637 light-years away.

Just from looking at our own solar system, we can see that planets come in a wide variety of colors -- from the dusty red of Mars to the bright blues of Uranus and Neptune. Planets like Jupiter have beautiful bands of color caused by variations in the atmosphere, while it's hard to even see the surface of Venus because its atmosphere is so thick. But there are other variations in color which planets can display, like a stunning rainbow-hued set of circular rings called a glory.

Glories are observed on Earth, and have been seen just once on another planet, Venus. But now, researchers believe they may have identified a glory on a planet outside our solar system for the first time. The extreme exoplanet WASP-76b could be host to the first known extrasolar glory, observed by the European Space Agency (ESA)'s Characterising ExOplanet Satellite (Cheops).

Read more
James Webb photographs two potential exoplanets orbiting white dwarfs
Illustration of a cloudy exoplanet and a disk of debris orbiting a white dwarf star.

Even though scientists have now discovered more than 5,000 exoplanets, or planets outside our solar system, it's a rare thing that any telescope can take an image of one of these planets. That's because they are so small and dim compared to the stars that they orbit around that it's easier to detect their presence based on their effects on the star rather than them being detected directly.

However, thanks to its exceptional sensitivity, the James Webb Space Telescope was recently able to image two potential exoplanets orbiting around small, cold cores of dead stars called white dwarfs directly.

Read more