An isolated galaxy, designated NGC 6789, is challenging current astronomical understanding by continuing to form stars despite a lack of apparent fuel sources. Located roughly 12 million light-years away in the sparsely populated Local Void, this galaxy has been actively birthing new stars for the past 600 million years, a phenomenon that puzzles scientists.
The Puzzle of Star Formation in Empty Space
Galaxies require substantial amounts of gas to sustain star formation. However, NGC 6789 resides in a region of space almost entirely devoid of matter. The Local Void, as its name suggests, is one of the emptiest areas of the universe, making the continued star birth within this galaxy particularly unusual. Most galaxies of similar age should have exhausted their original gas supply long ago.
Despite this expectation, NGC 6789 has formed stars equivalent to roughly 100 million times the mass of our Sun in the last 600 million years—about 4% of its total stellar mass. This ongoing activity suggests an unknown mechanism is replenishing the galaxy’s fuel supply, or that a previously unconsidered reservoir exists within it.
Deep Imaging Reveals No Obvious Answers
Researchers led by Ignacio Trujillo at the Institute of Astrophysics of the Canary Islands conducted deep imaging of NGC 6789 using the Two-meter Twin Telescope in Tenerife. The goal was to identify evidence of external gas inflow, such as remnants of a past galactic merger or an unseen stream of gas.
However, the new images revealed no disturbances in the galaxy’s shape, ruling out recent major interactions that could explain the influx of fuel. The lack of distortion suggests that any gas supply must either be internal, unusually diffuse, or sourced from a mechanism not yet understood.
Remaining Questions and Future Research
Possible explanations include the presence of unexpectedly large reserves of gas left over from the galaxy’s formation, or a tenuous nearby gas reservoir that has not yet been detected. The absence of clear evidence, however, leaves the mystery of NGC 6789’s sustained star formation unsolved.
Further research will focus on detailed spectroscopic analysis of the galaxy’s gas composition and distribution, as well as more sensitive searches for faint gas structures surrounding it. The continued study of NGC 6789 may reveal new insights into the processes that govern star formation in extreme environments, challenging existing models of galactic evolution.
The continued star birth in an isolated galaxy like NGC 6789 highlights the limitations of current astronomical understanding and underscores the need for ongoing exploration and theoretical refinement
