63 light-years away, a star is surrounded by a strange trail of dust that resembles a cat’s tail.
This structure is located around Beta Pictoris, a young star that astronomers have been observing for decades. It has planets and a vast disk of dust. This disk contains the remnants of the materials involved in their formation. It was within this system that the James Webb Space Telescope spotted an unusual shape in 2024.
Artist’s view of the Beta Pictoris system with its orange dust disk and a curved trail nicknamed the “cat’s tail.”
Credit: NASA, ESA, CSA, STScI, Ralf Crawford (STScI).
The trail appears to emerge from the disk before curving through space. It could measure up to 1,000 times the distance between Earth and the Sun, or about 150 billion kilometers. Researchers nicknamed it the “cat’s tail” simply because of its shape.
One detail nevertheless puzzled scientists: this structure appeared in infrared images from James Webb, but remained almost invisible in ordinary light. A team from the University of Arizona therefore reexamined observations from the Hubble Space Telescope, made between 2012 and 2025.
The new analyses have finally revealed part of the tail in visible light. It appears shorter than in the infrared images. The farther the dust moves from the star, the less of its light it reflects. However, it continues to emit heat that James Webb can detect.
Comparing the two telescopes provided more information about this dust. The particles are thought to be tiny, measuring on the order of a micrometer, and surprisingly porous. Their composition is thought to be rich mainly in carbon. Despite their small size, these grains absorb a great deal of visible light, which explains their dark appearance.
But where did such a large amount of dust come from? Astronomers are considering a collision between two large bodies, perhaps comparable to Pluto. The impact would have scattered debris that now forms this long trail.
Researchers have also reassessed its position in space. Rather than extending mainly behind the star, the tail may spread almost sideways, within the plane.
Hubble also revealed a distortion in the neighboring dust halo. It could result from the gravitational influence of a giant planet. New observations will make it possible to track the shape of the tail and test the hypothesis of an ancient collision.