The closest star that's about to go supernova is actually way nearer to us than we thought.
March 19, 2026
Original Paper
Confirming Nunki as the closest core collapse progenitor candidate to the Sun
arXiv · 2603.17011
The Takeaway
New measurements of the star Nunki (Sigma Sagittarii) reveal it is a tight binary system only 69 parsecs away, making it our nearest neighbor likely to end in a core-collapse explosion. The two stars are orbiting so closely that they will eventually merge, creating a ticking time bomb visible from Earth.
From the abstract
We have recently suggested that Nunki=Sigma Sagittarii is the closest core collapse progenitor candidate to the Sun based on a VLTI/GRAVITY observation that unveiled it as a $6.5+6.3 M_{\odot}$ binary at a projected separation of 0.60 au. Here we combine this observation with three VLTI/PIONIER archival and one previous MAPPIT observation to solve for the orbit of \textit{Nunki}, finding $a=1.26\pm0.05 \text{ au}$ ($P=134.779\pm0.025 \text{ days}$) and thereby confirming it as a close binary. Th