At a recent announcement in New Delhi, scientists from the Aryabhatta Research Institute of Observational Sciences (ARIES) revealed fresh insights into the formative years of a class of young stars known as Young Stellar Objects (YSO). Using ten years’ worth of infrared data delivered by NASA’s Wide‑field Infrared Survey Explorer (WISE) and its NEOWISE continuation, the research team traced how these nascent stars evolve.
ARIES operates as an autonomous centre within the Department of Science & Technology (DST). The paper, which appeared in The Astrophysical Journal Supplement Series, showed that a star’s early life is far more turbulent and variable than was previously assumed.
YSOs are essentially newborn stars, still in the stage where they haven’t begun the stable fusion of hydrogen in their cores. In the language of stellar evolution, this lies before they settle onto the main sequence of the Hertzsprung–Russell diagram—a graph that pairs a star’s temperature with its brightness.
In the study, Neha Sharma and Saurabh Sharma of ARIES examined light‑curve data for more than 22 000 YSOs located in the Milky Way’s most prolific star‑forming complexes. These dense clouds provide an ideal laboratory for watching how stars come into being.
By reviewing over a decade of WISE/NEOWISE observations at wavelengths of 3.4 and 4.6 µm, the team sorted YSO brightness variations into six broad classes: linear (steady brightening or fading), curved (non‑linear trends), periodic (regular oscillations linked to rotation or disk motion), burst (sudden spikes in luminosity), drop (abrupt dimming), and irregular (chaotic, unpredictable changes).
"The team found that as the dense molecular clouds contracts under their own gravity, at their centre forms a protostar – a hot, dense core surrounded by a rotating disk of material. The protostar emits light not from fusion but from the heat generated by gravitational collapse and mass accretion,” the Ministry said.
As the protostar continues to accrete gas from its circumstellar disk, the flow is not smooth; instead, it sporadically surges and stalls, producing rapid and often unpredictable shifts in brightness. Over time, the star’s own radiation pressure can expel the remaining envelope of cloud material, stopping further accretion and leaving a young pre‑main‑sequence star.
“These dynamic processes are what make YSOs such rich subjects for infrared monitoring. Infrared light penetrates the thick dust shrouds surrounding YSOs – offering a unique window into the otherwise hidden early evolution of stars,” the Ministry said.
Stay informed on all the latest news, real-time breaking news updates, and follow all the important headlines in world News on Latest NewsX. Follow us on social media Facebook, Twitter(X), Gettr and subscribe our Youtube Channel.
