Rather than reaching far behind Beta Pictoris, the Cat’s Tail may run sideways as seen from Earth. That possible arrangement emerged when researchers combined infrared observations with new images taken in visible light by the Hubble Space Telescope.
At a distance of 63 light-years from Earth, Beta Pictoris hosts the enormous Cat’s Tail, a feature believed to consist mainly of dust. It spans roughly 1,000 astronomical units, or 93 billion miles. The first direct sighting came from NASA’s James Webb Space Telescope, observing in infrared light. In Hubble’s visible-light images, the tail appears as a tail-like protrusion sticking out of the plane of a vast, disk-shaped accumulation of cosmic dust.
A group headed by University of Arizona researchers turned to Hubble to examine the structure more closely. Their findings appeared last month in The Astrophysical Journal Letters. Arin Avsar, the research lead and a doctoral student at the university, worked with his colleagues to determine the tail’s three-dimensional geometry from the two sets of images.
“We find that instead of extending for 1,000 astronomical units behind the star, the Cat’s Tail may extend straight sideways relative to us, and there is no third dimension to it,” Avsar explained. “It’s essentially in the same plane of the sky as the star and possibly extends a little bit behind it.”
The tail’s composition could account for its absence from previous visible-light observations. Avsar outlined the problem in a statement: “Oddly, this feature had previously only been seen with the James Webb Space Telescope, which detects infrared light, but remained invisible at shorter wavelengths, which has puzzled the community for a while.” He added: “We think the Cat’s Tail has eluded our observations in visible light until now because of what it’s made of.”
According to Avsar, almost all of the feature is organic refractory material with a heavy carbon content. “These long chains of carbon atoms absorb visible light, so they’re quite black.”
Scientists propose that the Cat’s Tail formed when large, Pluto-like planetary bodies struck one another, spreading vast quantities of dust across great distances. Those impacts may have supplied enough heat to vaporize carbon. As that material cooled, it could have formed fluffy, porous dust grains.
The observations also revealed a warp in the dust halo around Beta Pictoris. The team says that distortion could arise from the strong gravitational effects of at least three planets known to occupy the system.
With an age of about 23 million years, Beta Pictoris is far younger than our 4.6-billion-year-old solar system. Studying these findings could give researchers a picture of our system shortly after its formation. Interactions of a similar kind may also have helped shape the formation of our planets as they exist today.
