Astronomers find super-cold hydrogen clouds around Milky Way's black hole
Astronomers just found super-cold hydrogen clouds floating 13,000 light-years above our galaxy's center, inside the giant Fermi bubbles.
These chilly clouds—discovered with the Green Bank Telescope—give us fresh clues about what our Milky Way's central black hole has been up to lately.
Chilly clouds' discovery upends previous assumptions about our galaxy
The clouds are over 100 times colder than the blazing plasma around them. They're also huge, stretching up to 91 light-years wide.
Their survival in such a harsh spot suggests the Fermi bubbles formed just a few million years ago—not tens of millions as scientists thought.
As lead researcher Rongmon Bordoloi put it, finding them is "like spotting ice cubes in boiling water"—a sign that our galaxy's heart had a dramatic outburst not so long ago.
Discovery connects what we see in gamma rays and X-rays
The discovery shows that energetic blasts from the Milky Way's black hole have shaped its surroundings much more recently than we realized.
It also connects what we see in gamma rays (Fermi bubbles) and X-rays (eROSITA bubbles), giving us a clearer picture of how active—and surprising—our galactic center can be.