Narrow ring of gas found near the young star HD 152384

Observations of the 5-million-year-old star HD 152384 have revealed a thin, gaseous ring composed of refractory elements. Located near the star's dust sublimation radius, this ring likely formed from the collisions of rocky planetesimals. This system provides a unique glimpse into the early, violent processes of planet formation and the evolution of debris disks around young stars.

Star system: HD 152384 | Distance from the Sun: 419 light years

The young star HD 152384, located in the Sco-Cen association, possesses a structure that mimics a debris disk, revealing a thin ring of gas circulating near the star. This gaseous ring consists of refractory elements - substances that remain solid at high temperatures - such as iron, magnesium, silicon, and calcium. The presence of this material so close to the star suggests a secondary origin, likely resulting from the ongoing collisions of rocky bodies orbiting the star. This system is a rare example of a very young star exhibiting characteristics typically seen in older, gas-bearing debris disks.

To map the environment around HD 152384, data were collected using high-resolution optical and near-infrared spectrographs. By analyzing the light patterns, 74 distinct emission lines were identified. These lines showed specific shifts known as double-peaked profiles, which allow for the calculation of orbital motion. Mathematical models of these motions place the gas within a thin ring located at approximately 0.09 to 0.12 astronomical units from the star. This distance coincides with the dust sublimation radius, the region where temperatures are high enough to turn solid dust grains into gas.

The findings suggest that as small dust grains created by collisions drift inward toward the star, they reach this hot region and vaporize. This process creates a reservoir of atomic gas that settles into a stable ring. The discovery provides a new perspective on how rocky material is processed during the early stages of a star system's life, showing that intense collisions are common even at this youthful stage of development.

Key findings
A narrow gaseous ring exists between 0.09 and 0.12 astronomical units from the star.
The ring contains iron, magnesium, silicon, and calcium, resulting from sublimated dust.
The total mass of magnesium gas within the ring is measured at 2.2 times 10 to the power of 22 kilograms.
The gas structure is consistent with the vaporized remnants of colliding rocky planetesimals.
HD 152384 serves as a young analog for other known gas-bearing debris disk systems.

Scientific study

HD 152384: A 5 Myr old debris disk system showing a gaseous ring of refractory elements at the dust sublimation radius (external link)