Ancient Pinwheel Galaxy ✦
Astronomers have found a very ancient barred spiral galaxy with a bar—a central stellar structure around which the arms wind. It formed just a billion years after the Big Bang but already has a complex shape. This shows that barred spiral galaxies appeared in the Universe earlier than previously thought.
In the boundless cosmos, the James Webb telescope spotted a galaxy that looks like a giant pinwheel: with a straight bar at its center and the beginnings of spiral blades. Normally, a pinwheel needs a push to start spinning — but this one whirled into motion almost instantly after the Big Bang, when the universe was about a billion years old. Our own Milky Way needed ten times longer to do the same.
The galaxy's light has been traveling to us for over 13 billion years. All that time, the universe was expanding, and the light reddened (redshift) — a phenomenon discovered by Edwin Hubble. The powerful James Webb and Hubble telescopes didn't just take pictures (photometry); they also split the light into colors (spectroscopy) to read its chemical makeup (metallicity). It turned out the galaxy had already stockpiled heavy elements — nearly half as much as the Sun has. Star formation is seething inside it, and at the center rages an active galactic nucleus — a supermassive black hole greedily pulling in matter.
Nearby lurks a companion — a galaxy whose close proximity might have triggered all this furious activity. The evolution of this system raced ahead at a gallop while other galaxies were still learning to walk.
🎯 If you could see this galaxy's bar with the naked eye, it would be a tiny dot — smaller than Jupiter's disk in the sky.