For the first time, astronomers have captured images of a periodic rocky near-Sun comet breaking apart, a common fate for heavenly bodies with destabilized orbits. Because they pass so close to the Sun, they are challenging to study, and astronomers discover most of them by accident in solar telescope observations. Although these objects are rare, astronomers believe that they are too rare and that something is destroying them before they can dive into the Sun.
Astronomers from Macau, the US, Germany, Taiwan, and Canada observed an elusive near-Sun comet called 323P/SOHO with multiple telescopes. The group used the wide field of view of the Subaru Telescope to search for 323P/SOHO, finding it as it approached the Sun.
With this data, the researchers knew where to point the other telescopes to observe 323P/SOHO as it moved away from the Sun.
Surprisingly, they found that 323P/SOHO had changed remarkably during its close passage by the Sun, growing a long comet tail of ejected dust. The researchers believe that the intense radiation from the Sun caused parts of the comet to break off due to thermal fracturing. This loss mechanism could help explain what happens to near-Sun comets and why so few of them are left.
They found that 323P/SOHO rotates rapidly, taking just more than half an hour per revolution and that its color is unlike anything else in the Solar System. The research results are Hui et al. “The Lingering Death of Periodic Near-Sun Comet 323P/SOHO” in the Astronomical Journal on June 14, 2022.