When astronomers noticed ASASSN-24fw dim almost out of existence, it looked like it was the end for it. This star, steady for more than a decade, suddenly lost 97% of its brightness and seemed to vanish for eight long months (like that fling that decided to ghost you last summer).

To us stargazers, it was as if someone had turned down the dimmer switch on the light. But thanks to the exhaustive work of researchers at Ohio State University, we now have a good idea of what really happened.

ASASSN-24fw, the star that nearly disappeared

ASASSN-24fw is not just any star. It is an F-type star, a class slightly more massive and nearly twice the size of our Sun. It sits about 3,000 light-years from Earth, a far but still reachable neighbor in galactic terms. For over ten years, this star had shone steadily, giving scientists little reason to think it would suddenly change. Then came the surprise. From late 2024 to early 2025, it dimmed by 97%, leaving astronomers puzzled and intrigued.

The detective work behind the fading

The first big clue came from how the dimming looked. Using data from the All-Sky Automated Survey for Supernovae (a global network of small telescopes) researchers tracked ASASSN-24fw’s fading month by month. What they noticed was strange: the star’s color never changed, even as it grew fainter. Normally, when a star changes brightness because it is aging or burning fuel differently, its color also shifts. Since ASASSN-24fw stayed the same color, that meant something else must have blocked its light from our view.

The dusty disk theory

The Ohio State team concluded that a giant cloud of dust and gas crossed in front of the star, like a thick, hazy curtain. This dusty structure is estimated to be about 1.3 astronomical units across. To put that in perspective, that is even bigger than the distance between Earth and the Sun. The dust itself is made of clusters of carbon or water ice, similar in size to the larger grains of sand you might find on a beach.

That means ASASSN-24fw is not breaking down or dying—it is simply surrounded by material that occasionally blocks its glow from reaching us.

A secret partner in crime?

Still, the dusty disk does not tell the whole story. Researchers also suspect that ASASSN-24fw has a hidden companion star. This second star would be smaller, cooler, and much fainter. If the two stars are in orbit around each other, then the smaller one could influence the shape and movement of the disk. That would explain why the geometry lined up just right to produce such a dramatic eclipse.

In other words, ASASSN-24fw may be part of a binary system—two stars tied together by gravity. Binary stars are common in the galaxy, but this one is unusual enough to earn the title of “cosmic oddball.”

So why should we care that ASASSN-24fw played hide-and-seek for most of a year? For scientists, rare events like this test our theories and force us to improve them. Astronomers looked for similar cases and couldn’t find anything quite like it, which makes this discovery even more valuable.

Learning how dusty disks behave helps connect the dots between dying stars, newborn planets, and everything in between. For the rest of us, it is a reminder that even stars that seem calm can still surprise us in dramatic ways.

When will it vanish again?

Here is the catch: ASASSN-24fw’s vanishing act isn’t something you can set your backyard telescope to catch every year. Astronomers calculate that its eclipses happen about once every 43.8 years. That means the next time it should fade will be around the year 2068.

By then, new generations of astronomers will have access to even more powerful instruments, like upgraded space telescopes, that can track its every move. For now, scientists hope to use tools like the James Webb Space Telescope and the Large Binocular Telescope to watch ASASSN-24fw as it shines at full strength again.