Indian scientists detect complex hydrocarbons around a young Sun-like star

DD News brings a science report on a new finding by Indian astronomers using data from the James Webb Space Telescope.

Researchers have identified complex hydrocarbon molecules in the disk of a young Sun-like star, offering fresh information on how planets form and how basic chemical compounds behave in early stellar systems.

The study looks at T Chamaeleontis, a young star about 350 light-years away from Earth. The star is surrounded by a disk made of gas and dust, where planets are expected to form.

Scientists studied old data collected by the telescope’s Mid-Infrared Instrument. Their study showed clear signs of polycyclic aromatic hydrocarbons, known as PAHs. These are carbon-based molecules linked to early chemical activity that happens before planets are fully formed.

The research was carried out by scientists from the Indian Institute of Astrophysics under the Department of Science and Technology. The results were published in The Astronomical Journal.

By comparing data collected over 20 years, the team studied changes in light from the disk and how radiation reached different regions. The findings add to ongoing research on planet formation, disk changes, and the stability of chemical compounds around young stars.
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How JWST data revealed hidden molecules

Scientists used observations from NASA’s James Webb Space Telescope collected in 2022 and compared them with earlier data from the Spitzer Space Telescope recorded in 2002.

The comparison showed that emissions linked to PAHs had become stronger over time. However, the size and charge of the molecules did not change during this period.

T Chamaeleontis has a large gap in its circumstellar disk. This gap is believed to be caused by a forming planet. Normally, thick inner regions of such disks prevent ultraviolet radiation from reaching outer areas.

In this case, researchers found that a high accretion event led to a partial collapse of the inner disk wall. This allowed ultraviolet light to pass through and illuminate the outer disk.

Arun Roy, post-doctoral fellow at the Indian Institute of Astrophysics and lead author of the study, said this detection stands out. He stated, “This is one of the lowest-mass stars where PAHs have been clearly detected in a circumstellar disk.”

He also explained that the event acted like “a curtain lifting,” allowing scientists to observe chemical activity that was not visible earlier. The data helped confirm that the observed signals were linked to radiation exposure rather than changes in the molecules themselves.
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What do the findings mean for planet formation studies?

The study says the detected PAHs are small molecules with fewer than 30 carbon atoms. These molecules help scientists study chemical processes that occur in the early stages of planet formation.

Their detection shows that such compounds can exist in disks around low-mass stars in certain conditions.

Researchers say that forming planets can affect the disks around them. This interaction can change how light and radiation pass through the system. As a result, what scientists observe can vary over time.

Arun Roy noted that the observations helped uncover long-hidden processes, saying the illumination revealed activity “that had remained hidden for years.”

The findings provide data that can be used in future studies of young stellar objects and their disks. By understanding when and where such molecules appear, scientists can improve models of disk evolution and radiation flow.

The research also shows the value of long-term data comparison using different space telescopes. Together, the results contribute to broader efforts to study how planetary systems develop and how basic chemical compounds persist during early stages of stellar and planetary growth.

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