In 2026, astronomers confirmed a new planet orbiting a star about 297 light-years from Earth. That planet is TOI-5532 b, and while it is not a place anyone could visit or live on, it gives scientists another piece of the puzzle in understanding how planets form and what kinds of worlds exist beyond our solar system.
How Scientists Found TOI-5532 b
Astronomers used a method called the transit method to find this planet. Here is how it works: when a planet passes in front of its star, it blocks a tiny bit of the star’s light. Telescopes watching the star notice that the star gets very slightly dimmer for a short time. By measuring exactly how much dimmer it gets, and how often it happens, scientists can figure out that a planet is there.
This method does not let us see the planet directly. Instead, we are reading the shadow it casts. It is a careful, patient kind of science. You can explore other worlds found this way in our discovery timeline.
The transit method also tells scientists how big a planet is, because a larger planet blocks more light. And by watching the star very carefully over time, researchers can sometimes work out the planet’s mass as well. For TOI-5532 b, both of those measurements were made.
The Star at the Center: TOI-5532
Every planet needs a star, and TOI-5532 b orbits one called TOI-5532. This star has a surface temperature of 4,208 K. To put that in perspective, our own Sun has a surface temperature of about 5,778 K, so TOI-5532 is noticeably cooler than the Sun.
A star with a surface temperature in this range is often called a K-type star, sometimes nicknamed an orange dwarf. These stars are smaller and cooler than our Sun, but they are still much hotter and larger than the very small, dim stars known as red dwarfs. K-type stars are quite common in our galaxy, and scientists find them interesting because they can be stable for a very long time.
TOI-5532 sits 297 light-years away from us. A light-year is the distance light travels in one year — about 9.5 trillion kilometres. So this star is extremely far away, even though, on a cosmic scale, it is still a neighbour in our own corner of the Milky Way.
Size, Mass, and What Kind of World This Might Be
TOI-5532 b has a radius of 2.53 times Earth’s radius. That means if you put Earth side by side with this planet, TOI-5532 b would look noticeably larger. It is also much heavier, with a mass of 6.93 times Earth’s mass.
When scientists look at a planet’s size and mass together, they can make a rough guess about what the planet might be made of. A planet with about 2.5 times Earth’s radius and about 7 times Earth’s mass sits in an interesting middle ground. It is probably too big to be a bare rocky world like Earth or Mars, but it is smaller than the giant planets like Neptune.
Worlds in this size range are sometimes called sub-Neptunes — planets that are bigger than Earth but smaller than Neptune. Scientists think many sub-Neptunes have a rocky or icy core surrounded by a thick layer of gas. But we should be honest: we do not know for certain what TOI-5532 b is made of. Working out a planet’s true composition from this distance is very hard, and scientists are still developing the tools to do it well. You can read about other worlds like this in our atlas of known exoplanets.
A Very Short Year and a Very Hot Surface
One of the most striking things about TOI-5532 b is how quickly it orbits its star. One full orbit — one year on this planet — takes only 5.65 Earth days. That means in the time it takes you to finish a school week, this planet has already gone all the way around its sun and started again.
Orbiting so close to a star has consequences. Scientists estimate the planet’s likely temperature is around 617 K, which is about 344 degrees Celsius. That is hot enough to melt lead. This temperature is far outside what we think of as the habitable zone — the band of distances around a star where liquid water could potentially exist on a planet’s surface.
So TOI-5532 b does not sit in that zone. It is much too close and much too hot for liquid water on its surface, as far as we can tell. It is not the kind of place scientists would search for signs of life.
What We Still Don’t Know
As with most exoplanets — planets orbiting stars other than our Sun — there is a lot we simply have not measured yet. Scientists have not confirmed what atmosphere TOI-5532 b has, if any. Its exact surface conditions are unknown. And right now, it is the only known planet in its system, though that does not mean others won’t be found later as more data comes in.
TOI-5532 b is a useful world to study precisely because it sits in that middle ground between Earth-sized planets and Neptune-sized giants. Each confirmed planet like this one helps scientists test their ideas about how planetary systems are built, and slowly, carefully, the picture of what is out there gets a little clearer.