DMPP-8 b is a giant planet orbiting a star 248 light-years from Earth. It was discovered in 2026, and it is already giving scientists a lot to think about. Understanding worlds like this one helps us learn how planets form and what they can be made of.
Where in the Sky Is DMPP-8 b?
To find DMPP-8 b, you would need to travel 248 light-years from our solar system. A light-year is the distance light covers in one year — about 9.5 trillion kilometres. That is very far, but in the scale of our galaxy, it is still a relatively nearby neighbourhood.
The planet orbits a star called DMPP-8. Astronomers found DMPP-8 b using something called the radial velocity method. Here is how it works: as a planet orbits a star, its gravity gives the star a tiny tug. That tug makes the star wobble — ever so slightly — back and forth. Scientists can detect that wobble by watching how the star’s light shifts. When a star moves toward us, its light looks a little bluer. When it moves away, the light looks a little redder. By measuring those tiny shifts very carefully, astronomers can work out that a planet must be there, even without seeing it directly.
So far, DMPP-8 b is the only planet scientists have confirmed in this system. That doesn’t mean it’s alone — other planets might be there, too small or too far away for current instruments to catch.
How Big Is This World?
DMPP-8 b is large. Its radius — the distance from its centre to its surface — is 10.8 times the radius of Earth. Its mass, meaning how much matter it contains, is 81.1 times Earth’s mass. Those are big numbers, and they place DMPP-8 b firmly in the category of giant planets.
For comparison, our own solar system’s giant planets give a useful reference. Saturn is about 9.4 times Earth’s radius, and Jupiter is about 11.2 times. So DMPP-8 b sits between those two in size. If you want to see how it stacks up visually, our size comparison tool lets you place planets side by side to get a feel for the difference.
With 81.1 Earth masses, DMPP-8 b also falls between Saturn (about 95 Earth masses) and Neptune (about 17 Earth masses) in terms of mass — though it is closer to Saturn’s end. These kinds of comparisons help scientists start to picture what kind of world it might be.
What Is DMPP-8 b Probably Made Of?
When scientists know both a planet’s size and its mass, they can calculate its density — how tightly packed its matter is. Density is a powerful clue about what a planet is made of. A small, heavy world is probably rocky or metallic inside. A large, light world is probably full of gas.
DMPP-8 b has a large radius but a mass that, while big, is not enormous for that size. That combination suggests it is not a dense, rocky world. Instead, scientists would likely describe it as a gas-rich giant — a planet dominated by thick layers of hydrogen and helium gas, much like Jupiter and Saturn in our solar system.
However, the exact mix of materials inside is uncertain. Some giant planets have a solid or slushy core buried beneath their gas layers. Others might have more water or ice mixed into their deep interiors. Without more measurements — like data on its atmosphere — scientists can only make educated guesses. You can explore how size and mass together reveal planet types using the mass-radius diagram, which shows where different kinds of planets tend to cluster.
What we can say is that DMPP-8 b almost certainly does not have a hard surface you could stand on. Beneath its outer atmosphere, the pressure and temperature would rise steeply, and any boundary between “atmosphere” and “interior” would be gradual rather than sharp.
A Fast Year on a Giant Planet
One year on DMPP-8 b — the time it takes to complete one full orbit around its star — lasts just 62.9 Earth days. That is shorter than two of our months. By the time you finished reading a novel, this planet would have moved a noticeable slice of the way around its star.
A short year usually means a planet is orbiting close to its star. Close orbits mean the planet receives a lot of heat. Scientists haven’t published an exact temperature measurement for DMPP-8 b yet, but given how near it likely sits to its star, it is probably a warm or hot world. That would put it in a different category from the cold, distant giants in our own solar system.
A planet this large, this warm, and this close to its star is sometimes called a warm giant or, if it is especially hot, a hot Jupiter — even if it is not quite as massive as Jupiter. These worlds are fascinating because we don’t fully understand how they got so close to their stars. Some scientists think they formed farther out and slowly moved inward over millions of years. Others think the story is more complicated.
The Star Behind the Planet
Every planet needs a star, and DMPP-8 b’s star has a surface temperature of 6,009 Kelvin. Kelvin is a temperature scale used in science; 0 Kelvin is as cold as anything can possibly get, and room temperature on Earth is about 294 Kelvin. At 6,009 K, DMPP-8’s surface is hot — hotter than our own Sun, which sits around 5,778 K.
That slightly higher temperature is why the article calls it a “white star.” Stars are not all the same colour. Cooler stars look orange or red. Stars around our Sun’s temperature look yellow-white. Stars a bit hotter, like DMPP-8, appear whiter to the eye because they pour out more blue and violet light alongside all the other colours. Scientists sort stars into categories called spectral types, and DMPP-8 sits near the boundary between the yellow-white and white categories.
A slightly hotter star also puts out a bit more energy, which matters for any planet orbiting close by. That extra energy would add to the warmth DMPP-8 b already receives because of its short orbit.
What We Still Don’t Know
DMPP-8 b was only discovered in 2026, so a lot of its story is still being written. Scientists haven’t yet measured its temperature directly, what its atmosphere might contain, or whether it has any moons. We also don’t know if other planets share its system. The radial velocity method that found it tells us about mass and orbit, but it doesn’t reveal surface conditions or atmospheric chemistry — those would need different tools and future observations.
As telescopes and instruments improve, worlds like DMPP-8 b will slowly give up more of their secrets. For now, it stands as a clear example of how much we can learn — and how much we still have to learn — about the enormous variety of planets scattered across our galaxy.