In 2026, astronomers confirmed a new world orbiting a star 218 light-years away. That world is TOI-7384 b, and it belongs to a class of planets we have no example of in our own solar system. It is already giving scientists plenty to think about.
Where in the Sky Does TOI-7384 b Live?
TOI-7384 b orbits a star called TOI-7384. The star sits about 218 light-years from Earth. A light-year is the distance light travels in one full year — roughly 9.5 trillion kilometers. So 218 light-years is an almost impossible distance to picture, yet in the scale of our galaxy, it is actually quite close. Our galaxy is about 100,000 light-years across, so TOI-7384 is practically a neighbor.
So far, scientists have found only one planet in this system. That does not mean TOI-7384 b is alone — it just means no other planets have turned up yet. Searches for other worlds in the system are still possible, and many single-planet systems later turn out to have companions hiding in the data.
A Strange, Fast Year
One of the first things that stands out about TOI-7384 b is how quickly it orbits its star. One full orbit — what we would call a year on that planet — takes just 6.23 Earth days. To put that another way, by the time a week passes on Earth, TOI-7384 b has already gone all the way around its sun.
This happens because the planet orbits very close to its star. The closer a planet is to its star, the faster it must move to stay in orbit, and the shorter its year becomes. Mercury, the innermost planet in our solar system, has a year of about 88 Earth days — and that already feels fast. TOI-7384 b laps its star more than 14 times in that same span.
Orbiting so close to a star also means receiving a lot of heat. Scientists estimate the likely temperature of TOI-7384 b is about 378 K, which works out to roughly 105 degrees Celsius. That is hotter than boiling water. It is worth noting this is an estimate, and scientists haven’t directly measured conditions on the planet’s surface or in its atmosphere yet.
Size, Mass, and What Kind of World This Might Be
TOI-7384 b has a radius about 3.56 times that of Earth. It also has a mass — that is, the total amount of material it contains — about 12.4 times Earth’s mass. These two numbers together tell scientists a great deal about what the planet might be like inside.
A planet this size and mass falls into a category called a mini-Neptune. Mini-Neptunes are worlds larger than Earth but smaller than Neptune in our solar system. Scientists think they likely have a rocky or icy core surrounded by a thick layer of gas or other lightweight materials. They are one of the most common types of planets found around other stars, yet we have none in our solar system — which makes them genuinely interesting to study.
The density of TOI-7384 b — how tightly its mass is packed into its size — hints that it probably is not a pure rock world. A planet that massive but that large is likely puffed out with gas or other light materials. However, scientists haven’t directly measured its atmosphere yet, so we can only say what seems probable based on its size and mass together. You can explore other worlds like this in the planet atlas.
The Star TOI-7384 — A Cool, Dim Neighbor
The star at the center of this system, TOI-7384, has a surface temperature of 3,185 K. Our own Sun has a surface temperature of about 5,778 K, so TOI-7384 is notably cooler. Stars like this are called red dwarfs — small, dim stars that burn their fuel slowly and can live for tens of billions of years. They are the most common type of star in our galaxy.
Because red dwarfs are cooler, they give off less light and heat. A planet would need to orbit very close to one just to receive enough warmth to stay above freezing — and TOI-7384 b does orbit close. Whether that closeness is a good thing for any chance of habitability is complicated. Scientists haven’t yet measured whether the planet falls in the habitable zone, the range of distances where liquid water could exist on a world’s surface, though at 105 degrees Celsius its estimated temperature suggests conditions there would be harsh.
How Scientists Found It: The Transit Method
TOI-7384 b was discovered in 2026 using the transit method. This technique works by watching a star very carefully over time. When a planet passes in front of its star from our point of view, it blocks a tiny fraction of the star’s light. Scientists can detect that small dip in brightness and use it to figure out the planet’s size, how long its orbit takes, and other key details.
The transit method works especially well for planets that orbit close to their stars, because those planets cross in front of the star more often. TOI-7384 b, with its 6.23-day orbit, gives scientists many chances to observe each transit. You can see how this discovery fits into the broader story of finding new worlds on the discovery timeline.
What We Still Don’t Know
TOI-7384 b is newly confirmed, and there is still a lot to learn. Scientists haven’t measured what its atmosphere is made of, if it has one at all. They haven’t confirmed whether any other planets share its system. The estimated temperature is a calculation based on the planet’s orbit and its star’s energy, not a direct reading from the planet itself. Each of these open questions is a chance for future telescopes and missions to add to what we know.
TOI-7384 b is a good reminder that every confirmed exoplanet — an exoplanet is simply a planet orbiting a star other than our Sun — is a new data point in a much bigger picture. The more of these worlds we find and study, the better we understand what planets can be, and perhaps eventually, what conditions life might need to take hold.