BHUBANESWAR: In a significant discovery, astronomers from National Institute of Science Education and Research (NISER), Bhubaneswar, claimed to have uncovered the place where baby exoplanets begin to form in the galaxy.
The team led by Liton Majumdar, a faculty at the School of Earth and Planetary Sciences (SEPS), NISER, has observed the earliest stages of exoplanet formation outside the solar system by using the Atacama large millimeter/submillimeter array (ALMA), an advanced telescope with 66 high-precision antennae that can observe electromagnetic radiation at millimetre and submillimetre wavelengths.
Estimated to be one to five million years old, this young system has been enveloped in a swirling ring of dust and gas - the raw material that fuels the birth of baby exoplanets. Although exoplanets can form in binary or multi-star systems, direct evidence of the process of their formation has been difficult to capture until now.
Principal investigator Majumdar and his PhD student Parashmoni Kashyap led the team that zoomed in on the most massive circumbinary disk ever detected around T Tauri stars, which are less than about 10 million years old, uncovering where baby exoplanets begin to form.
Utilising ALMA’s high-resolution capabilities, they have pinpointed emissions from key molecules like diazenylium (N2H+), one of the few molecular ions observed in interstellar clouds, and DCO+, one of the most common deuterated molecules in cold molecular cloud, providing a clear view of the cold, dense regions of the GG Tau A disk where exoplanets begin to emerge.
“The regions, referred to as the mid-plane, are where exoplanets gather their building materials. But these are very challenging to observe as many molecules freeze onto dust particles, making them invisible. During the study we could get an unprecedented glimpse into the hidden and frigid environments where baby exoplanets are taking shape,” said Majumdar.
The team’s observations have successfully detected rotational temperatures as low as 12 K (-261.15 degree C) and 16 K (-257.15 degree C) much colder than the carbon monoxide (CO) freezing temperature allowing them to discover regions closer to the mid-plane more effectively than ever before.
They have studied GG Tau A, a triple-star system located about 150 parsecs away in the Taurus constellation, where the possible presence of three baby exoplanets - GG Tau Ac, GG Tau Ad, and GG Tau Ae - was previously reported by the same team.
“The study is a significant step forward in unravelling the mysteries of how exoplanets form in complex and multi-star environments. The findings offer a tantalising preview of what telescopes like ALMA might reveal about the birthplaces of distant worlds, bringing us one step closer to understanding how planetary systems like our own come into existence,” Majumdar said.