BENGALURU: Scientists at Isro’s Physical Research Laboratory (PRL) have captured new images and spectra of the interstellar comet 3I/ATLAS as it moves out of the inner Solar system after its recent perihelion passage.Using PRL’s 1.2m telescope at Mount Abu, researchers observed the comet between Nov 12 and 15. The images show a near-circular coma, the cloud of gas and dust that forms around a comet’s nucleus when solar heating causes surface ices to sublimate.
“In the present geometry, any dust tail would lie behind the comet relative to the Earth, while deeper multiband images could reveal the ion tail,” Isro said.Ahead of morning twilight, the team also recorded a spectrum of the comet’s light. It showed clear emission features associated with Solar system comets, including CN, C2 and C3 bands at shorter wavelengths.“Researchers calculated the production rates of these molecular emissions, which describe how much gas is released from the nucleus into the coma. For 3I/ATLAS, the values are around 10²⁵ molecules per second. The ratios of these rates place the object among the ‘typical comets’ of the Solar system despite its interstellar origin,” Isro said.PRL’s Mount Abu telescope, situated at an altitude of 1,680m near Gurushikhar, supports studies ranging from exoplanets to high-energy sources. The team plans further observations as 3I/ATLAS moves into darker skies.