Is Procyon B bigger than the sun?

Procyon B: Not a Giant, But Seriously Dense

So, is Procyon B bigger than our Sun? Absolutely not! Forget any images of a star dwarfing our own. Procyon B is what’s known as a white dwarf. Think of it as the stellar equivalent of a heavyweight boxer who’s shrunk down but kept all the muscle. It’s the leftover core of a star that’s burned through all its fuel and collapsed in on itself.

Now, when I say “collapsed,” I mean collapsed. We’re talking about something incredibly small compared to the Sun.

To give you a sense of scale, Procyon B’s radius is only about 1.2% of the Sun’s. Put another way, it’s roughly the size of Earth. The Sun, on the other hand, is just massive. It’s got a radius close to 700,000 kilometers.

But here’s where things get interesting. Don’t let its size fool you. Procyon B is unbelievably dense. It packs over half the Sun’s mass into that tiny Earth-sized volume. Imagine squeezing that much stuff into something so small! That’s why it has an average density of about a third of a metric ton per cubic centimeter. That’s heavy!

Procyon B isn’t a loner, either. It hangs out with Procyon A, a brighter, larger star. Procyon A is what we call a subgiant. It’s in the process of evolving off the main sequence, which is basically the stellar version of leaving home and figuring out what to do next. These two stars are in a cosmic dance, orbiting each other every 40.8 years. Their average distance is around 15 astronomical units, a bit less than the distance between the Sun and Uranus.

Back in 1844, astronomers noticed that Procyon A was wobbling slightly. They figured something must be tugging on it, and that’s how they first suspected Procyon B existed. It wasn’t until 1896 that they actually saw it. Procyon B is faint and close to its much brighter companion, making it a tough target to spot.

Scientists estimate that Procyon B is around 1.37 billion years old. That’s pretty old, but still younger than our Sun. It probably started as a star about twice the mass of Procyon A. After it ran out of fuel, it expanded into a giant, shed its outer layers, and left behind that super-hot, super-dense core we now call Procyon B.

So, while Procyon B might not be a giant, it’s still a fascinating object. It teaches us a lot about how stars evolve and what happens to them when they die. It’s a reminder that even the smallest things can pack a serious punch!