Dubois Astronomers Discover Unique Galaxy from the Early Universe

In a groundbreaking find, astronomers in India have uncovered a galaxy that challenges prior assumptions about the early Universe. Utilizing the James Webb Space Telescope (JWST), a team led by Rashi Jain has identified a fully formed spiral galaxy dating back to just 1.5 billion years after the Big Bang—approximately one-tenth of its current age of 13.8 billion years.

The study was spearheaded by Jain and her mentor, Prof. Yogesh Wadadekar, from the National Centre for Radio Astrophysics (NCRA-TIFR) in Pune, with their findings published in November in the European journal Astronomy and Astrophysics.

Named Alaknanda, after a river in the Himalayas, this galaxy astonishes researchers, as it defies expectations for galaxies from such an early period, which were believed to be small and chaotic. In stark contrast, Alaknanda displays characteristics akin to our own Milky Way, showcasing a well-organized spiral structure.

Prof. Wadadekar expressed that Alaknanda appears “remarkably similar to the Milky Way,” existing in a time when the Universe was still young. He remarked that the formation of such a massive disc with spiral arms in a mere few hundred million years is “astonishing by cosmic standards.”

With a span of nearly 30,000 light-years, this galaxy is about one-third the size of the Milky Way and houses around 10 billion stars. Researchers note it is forming new stars 20–30 times faster than the Milky Way currently does.

Jain initially discovered Alaknanda while analyzing roughly 70,000 celestial objects with JWST, noticing its distinct spiral structure. She described it as exhibiting the classic “beads-on-a-string” pattern, showcasing beautifully clustered stars along its arms—an exceptionally rare sight for early Universe galaxies.

When Jain first shared her discovery with Prof. Wadadekar, he was initially skeptical. The implications of such a developed and massive galaxy emerging so soon after the Big Bang raise new questions about galaxy formation in that chaotic early period.

Typically, astronomers expect early galaxies to be faint, small, and irregular. However, Alaknanda suggests that initial galaxies may have evolved in a more advanced and organized manner than previously believed. The James Webb Telescope has revealed several ancient galaxies, but Alaknanda stands out, reinforcing the notion that the early Universe was capable of fostering complex structures much sooner than anticipated.

As the light from Alaknanda has traversed 12 billion years to reach Earth, astronomers are witnessing the galaxy as it was in the distant past. The current state of Alaknanda remains a mystery. Prof. Wadadekar humorously notes, “If you want to know where it is now, you’ll have to wait another 12 billion years.”

The research team aims to conduct further observations with JWST or the ALMA observatory in Chile to delve into how such a significant spiral galaxy formed its structure in the early stages of cosmic history. Understanding galaxies like Alaknanda could provide profound insights into the evolutionary trajectory of galaxies into the structures we observe today.