By David Warner 
The space next door, cosmically speaking, is the Alpha Centauri system. It is the closest star system to our own, a place astronomers have dreamed of visiting for centuries. This system is special because it has not one, but three stars. Two of them, Alpha Centauri A and Alpha Centauri B, are very much like our own Sun. The third, Proxima Centauri, is a small, dim red dwarf that is technically the closest single star to us. We already know Proxima Centauri has planets, but the “holy grail” has always been finding a planet around the Sun-like stars, A or B.
Finding planets there has been incredibly difficult. The light from these bright stars is like a blinding glare, making it almost impossible to spot the faint pinprick of light from an orbiting planet. But now, we have the most powerful space telescope ever built: the James Webb Space Telescope (JWST). And recent news, based on observations made in 2024 and analyzed into 2025, suggests JWST might have done it. It captured an image of something right next to Alpha Centauri A.
This “something” is not a small, rocky world. Instead, it looks like a “gas giant,” a massive planet perhaps many times larger than our own Jupiter. This is not a confirmation. It is a “candidate,” a very exciting “maybe.” Scientists are now in the middle of a careful, patient process to find out if this is a real planet or just a cosmic illusion. So, how did Webb spot this hidden object, and what will it take to prove it is really a planet?
The Alpha Centauri system is our closest stellar neighbor, located about 4.37 light-years away. To put that in perspective, a light-year is the distance light travels in one year, which is about 5.88 trillion miles. This distance is enormous—our fastest current spacecraft would take over 70,000 years to get there—but in the grand scale of the universe, it is right next door. This system is a “triple star” system, meaning it has three stars all bound together by gravity. The two main stars are Alpha Centauri A and Alpha Centauri B. They are a binary pair, orbiting each other in a long, slow dance that takes about 80 years to complete.
Alpha Centauri A is the star we are focused on. It is a star very much like our Sun, just a little bit larger and a little brighter. If we could swap it with our Sun, our sky would look very familiar. Alpha Centauri B is slightly smaller and dimmer than our Sun, more orange in color. Further out, orbiting this main pair at a great distance, is Proxima Centauri. Proxima is a tiny, cool red dwarf star. Because it is on a wider orbit, it is currently the closest of the three stars to Earth. We know Proxima has at least two, and possibly three, confirmed planets. One of them, Proxima b, is an Earth-sized planet in the star’s “habitable zone,” making it a primary target in the search for life. However, finding a planet around the Sun-like star Alpha Centauri A would be even more exciting, as it would be a system much more like our own.
Finding a planet around a nearby, bright star is one of the hardest jobs in astronomy. The problem is simple: stars are incredibly bright, and planets are incredibly dim. A planet does not make its own light; it only reflects a tiny, tiny fraction of the light from its star. Trying to see a planet like Jupiter next to a star like Alpha Centauri A is like trying to spot a single firefly hovering right next to a giant, blinding stadium searchlight from miles away. The star’s glare completely overwhelms the planet’s faint light.
To get around this, astronomers need a way to block the star’s light. This is done using a special instrument called a “coronagraph.” A coronagraph is basically a very precise, high-tech “thumb” inside the telescope that you can move to cover the exact spot where the star is. This blocks the intense glare, creating an artificial eclipse. Once the star’s light is suppressed, you have a much better chance of seeing the faint glow of a planet that might be orbiting it. This technique is called “direct imaging” because you are literally trying to take a picture of the planet itself.
Even with a coronagraph, the task is extremely difficult. The telescope has to be perfectly stable, and any leftover light from the star can create false signals or “artifacts” that look like planets. This is why we need a telescope as advanced as the James Webb Space Telescope. It is located deep in space where it is very cold and stable, and it “sees” in infrared light. This is a huge advantage, as young gas giant planets are often warm and glow brightly in infrared, making them stand out more against the background. Webb’s power is what allowed it to peer into the glare of Alpha Centauri A and find the potential candidate that has scientists so excited.
The James Webb Space Telescope (JWST) used its powerful infrared cameras and its advanced coronagraph to stare at Alpha Centauri A. The goal was to block the star’s light and hunt for anything orbiting it. After the observations were taken, scientists had to do a lot of complex image processing. This involves subtracting the star’s remaining light very carefully to reveal any faint dots hiding in the noise. When they finished, they found one. A small, distinct point of light showed up at a distance from the star that would be similar to the orbit of Saturn or Uranus in our own solar system.
This object, which some researchers are informally calling “C1” (Candidate 1), is intriguing because of its brightness and color in infrared light. Based on its characteristics, it does not look like a small, rocky planet. Instead, it appears to be a “gas giant,” a massive world possibly 5 to 10 times more massive than our own Jupiter. This would make it a “super-Jupiter.” This is exactly the type of planet that direct imaging is best at finding—a large, warm planet that is far enough from its star not to be completely lost in the glare.
It is crucial to understand that scientists did not see a “planet” with continents or clouds. They saw a dot. The excitement comes from the fact that this dot is in the right place, has the right brightness, and behaves like a planet should in their data. However, there are other possibilities. It could be an “artifact,” a sort of technical glitch or reflection inside the telescope’s optics, though JWST is designed to minimize these. Or, and this is the most likely alternative, it could be a distant background object, like a faint galaxy or another star from far across the universe that just happens to be in the same line of sight.
This is the most important question in planet hunting, and science has a brilliant method for answering it. The test is called the “common proper motion” test. It sounds complicated, but the idea is very simple, and it all comes down to a “cosmic waiting game.” Stars in our galaxy are not standing still; they are all moving through space. Because Alpha Centauri is so close to us, it appears to move across our sky relatively quickly compared to the very distant background stars. This apparent movement is called its “proper motion.”
Here is how the test works. We have the first set of images from JWST taken at one point in time. Let’s call this “Epoch 1.” In this picture, we see Alpha Centauri A and the faint candidate dot next to it. Now, scientists must wait. They will let some time pass, perhaps a year or two, and then use JWST to take another picture of Alpha Centauri A. This is “Epoch 2.”
When they compare the two pictures, one of two things will have happened. If the candidate dot was just a distant background star or galaxy, Alpha Centauri A will have moved across the sky (due to its proper motion), but the background dot will have stayed in the same place. The star and the dot will have separated. But, if the candidate dot is a real planet, it is bound to Alpha Centauri A by gravity. It is part of its system. Therefore, as Alpha Centauri A moves through space, the planet must move with it. In the “Epoch 2” image, the star and the dot will still be next to each other, having moved together across the sky. This is “common proper motion,” and it is the gold standard for confirming a directly imaged planet. Scientists are currently waiting to conduct this second observation, which will give us the final yes or no.
A gas giant is a massive planet composed mostly of gases like hydrogen and helium, with a small, rocky core deep inside. They do not have a solid surface you could stand on. In our own solar system, Jupiter and Saturn are the prime examples. This potential planet at Alpha Centauri A appears to be a “super-Jupiter,” meaning it is even larger and more massive than our own Jupiter. While you cannot live on a gas giant, finding one in this system is still a monumental discovery for several reasons.
First, it tells us about how planets form around Sun-like stars. Seeing a large gas giant far from its star helps confirm our theories about solar system “architecture.” Second, a gas giant acts like the 800-pound gorilla of its solar system. Its immense gravity shapes everything around it. It can toss smaller planets around, kick asteroids and comets out of the system, or even pull them into itself. This is why Jupiter is often called Earth’s “shield,” as it “vacuums up” many dangerous objects that might otherwise hit us.
Finding a “Jupiter” in the Alpha Centauri A system would give us vital clues about the rest of the system. If this giant is in a stable, distant orbit, it might actually protect smaller, rocky planets that could be orbiting closer to the star. Its presence could create a stable environment where an “Earth 2.0” could exist. On the other hand, if its orbit is wild or unstable, it might have already destroyed any smaller planets. Finding this giant is the first step to understanding the system’s complete story.
This is the question at the heart of our fascination with Alpha Centauri. Could there be a small, rocky planet like Earth, orbiting in the “habitable zone” of this Sun-like star? The habitable zone, sometimes called the “Goldilocks zone,” is the “just right” range of orbits where the temperature is not too hot and not too cold, allowing liquid water to exist on a planet’s surface. Since water is essential for all life as we know it, this is the first place we look. Alpha Centauri A, being a Sun-like star, absolutely has a habitable zone very similar in size and location to our own.
This new candidate, the gas giant, is not in the habitable zone. It is orbiting much farther out, where it is very cold. But its discovery is actually fantastic news for the search for an “Earth” there. The fact that a giant planet could form and exist in that system proves that the system is capable of making planets. It is not a barren, planet-less system. The next question is what this giant’s gravity is doing to the inner system.
As we discussed, the gas giant could be a protector, shielding the inner habitable zone from dangerous comets. Or, it could be a disruptor, whose gravity makes the habitable zone unstable. Scientists will be able to figure this out by studying the giant’s orbit (if it is confirmed). The discovery of this “maybe-planet” is a powerful motivator. It proves that JWST can see planets there, and it will push astronomers to aim the telescope at Alpha Centauri A again, this time looking even closer to the star, right into that warm, watery “Goldilocks zone” to hunt for a true sibling to our own Earth.
The James Webb Space Telescope is a game-changer for finding planets, and it works very differently from past telescopes like Kepler or TESS. For decades, the two most successful ways to find exoplanets (planets outside our solar system) were indirect methods. The first is the “transit method.” This is what the Kepler telescope did. You stare at a star and wait for its light to “dip” or dim very slightly. This dip means a planet has passed in front of the star from our point of view, blocking a tiny bit of its light. This method has found thousands of planets, but it only works if the planet’s orbit is perfectly lined up with our line of sight.
The second old method is the “radial velocity” or “wobble” method. A large planet’s gravity does not just pull on other planets; it also pulls on its star, making the star “wobble” back and forth ever so slightly. Astronomers can measure this wobble by looking at the star’s light. This method is great for finding massive planets that are close to their star. This is how the planets around Proxima Centauri were found. Both of these methods are “indirect”—you never actually see the planet itself, just its effect on the star.
Webb is pioneering the “direct imaging” method, which we talked about. It is taking an actual picture of the planet. Webb is uniquely suited for this for three main reasons. First, it sees in infrared light. Stars like Alpha Centauri A shine brightest in visible light, but a young, gassy planet is relatively warm and glows in infrared. This means the “glare” problem is less extreme in infrared. Second, Webb has a suite of state-of-the-art coronagraphs to block the star’s light. Third, it is in deep space, far from Earth’s blurry atmosphere, and it is kept incredibly cold, so its own heat does not interfere with the faint heat signals from a planet. This combination of infrared vision, high-tech blinders, and a super-stable location is what allows Webb to do what no telescope has ever done: capture a photograph of a potential planet next door.
We are standing at a thrilling, but uncertain, moment in astronomy. The James Webb Space Telescope has used its incredible power to peer into the glare of our nearest Sun-like star and has found a tantalizing “maybe.” This candidate, a potential gas giant larger than Jupiter, could be the first planet ever directly seen in the Alpha Centauri system. But science is a process of patience and proof. The title of “planet” must be earned.
Scientists are now playing a “cosmic waiting game.” They are waiting to take that all-important second snapshot. Only then, by checking for “common proper motion,” will we know if this dot is a true companion to Alpha Centauri A or just a distant imposter. Either way, the experiment is a victory. It proves that our technology has finally reached a level where we can directly hunt for worlds in our nearest neighboring systems. This “maybe” opens the door, encouraging us to look even harder for the true prize: a small, blue world, hiding in the life-giving warmth of our stellar neighbor.
If this giant planet is real, what else do you think is hiding in the shadows of our nearest neighbor star?
The Alpha Centauri system is about 4.37 light-years away from Earth. A light-year is the distance light travels in a year, which is almost six trillion miles, so it is incredibly far for us, but it is our closest stellar neighbor in the galaxy.
No, it is the closest Sun-like star to Earth. The single closest star to us is Proxima Centauri, a small red dwarf which is part of the same triple-star system but is currently slightly closer to us than its two big brothers.
A gas giant is a very large planet that is made up mostly of hydrogen and helium gas, much like our own Jupiter or Saturn. They do not have a solid surface that you could stand on, and they often have powerful storms and many moons.
The distance is simply too great. Even our fastest robotic space probes, traveling at tens of thousands of miles per hour, would take over 70,000 years to cross the 4.37 light-years of space to get to the Alpha Centauri system.
A coronagraph is a special tool inside a telescope that works like a tiny, precise shield. Its job is to block the blinding light from a central star, which allows astronomers to see very faint objects, like planets, that are orbiting close to it.
The biggest difference is the light they see. The Hubble telescope sees mostly in visible light, the same light our eyes see. The James Webb Space Telescope (JWST) is optimized to see in infrared light, which we feel as heat. This allows Webb to see objects that are colder, older, or hidden behind dust.
This is the “gold standard” test to confirm a planet. Stars move through space. If a faint dot is a real planet, it will move with its star. If the dot is just a distant background galaxy, the star will move, and the dot will be left behind.
No, the candidate is believed to be orbiting very far from Alpha Centauri A, much farther out than the star’s habitable “Goldilocks” zone. At that distance, it would be far too cold for liquid water to exist, and it is also a gas planet, not a rocky one.
Yes, but not around Alpha Centauri A (yet). We have confirmed at least two planets, and possibly a third, orbiting the system’s other star, the small red dwarf Proxima Centauri. One of those planets, Proxima b, is Earth-sized and in its star’s habitable zone.
Scientists will need to take a second observation with the James Webb Space Telescope. This will likely happen in 2025 or 2026. By comparing the new image with the first one, they can check if the object has moved with the star, which would confirm it is a real planet.