Intense solar radiation may cause comet 323P/SOHO to disintegrate and develop a long dust tail.
Comet 323P/SOHO as observed by the Subaru telescope on December 21, 2020 (left) appeared as a mere dot, while the CFHT telescope observed it on February 11, 2021 (right), showing a long tail. Photo: Subaru Telescope/CFHT/Man-To Hui/David Tholen
Astronomers have employed a multitude of ground-based and space telescopes to capture images of the disintegrating comet 323P/SOHO near the Sun. “This is the first time a comet like this has been spotted during its disintegration and could help explain the scarcity of comets near the Sun,” the National Astronomical Observatory of Japan (NAOJ) announced on June 15.
Many comets near the Sun are challenging to detect and track. Their eccentric orbits gradually draw them closer to the Sun. Scientists are striving to understand why they don’t detect many comets of this kind.
To gain a better understanding of comets near the Sun, a team of astronomers from Macao, the United States, Germany, Taiwan, and Canada observed 323P/SOHO using various telescopes, including the Subaru ground-based telescope, Canada-France-Hawaii Telescope (CFHT), Gemini North Telescope, Lowell’s Discovery Telescope, and the Hubble Space Telescope.
Comet 323P/SOHO displayed a significant difference before and after its approach to the Sun. When Subaru discovered the comet in December 2020, it appeared as a mere dot. However, images from early 2021 showed that it had developed a long dust tail.
The research team believes that intense solar radiation causes many comet portions to disintegrate due to a phenomenon similar to thermal cracking, much like how ice cubes crack when hot water is poured over them. This process of mass reduction may help explain what happens to comets near the Sun and why only a few of them remain.
The research team published their findings in the Astronomical Journal on June 14, describing comet 323P/SOHO as “burnt to death.”
Comet 323P/SOHO is a peculiar object. It rotates very rapidly, completing each rotation in just over half an hour, and its color differs from anything else in the solar system. Currently, the group of astronomers aims to observe further to determine if other comets near the Sun share these characteristics.