The Solar System’s little pocket of the Milky Way is, interestingly enough, exactly that. Our star resides in an unusually hot, low-density compartment in the galaxy’s skirts, known as the Local Hot Bubble (LHB).
Why it’s not called the Local Hot Pocket is anyone’s guess; but, because it’s an anomaly, scientists want to know why the region exists.
Now a team of astronomers has mapped the bubble, revealing not just a strange asymmetry in the pocket’s shape and temperature gradient, but the presence of a mysterious tunnel pointing towards the constellation Centaurus.
Source:
The SRG/eROSITA diffuse soft X-ray background
https://www.aanda.org/articles/aa/full_html/2024/10/aa51045-24/aa51045-24.html
What does interstellar tunnel mean in this context?
The article tells you. It’s a change in temperature between the various pockets of space.