How a crowd-favorite planet became the hellish world it is today

Just 41 light years from Earth, our planet has a cousin from hell. It’s a strange world named 55 Cnc e, also known as Janssen, which tests the limits of a planet’s proximity to its host star before exploding; evaporating; merger. Janssen orbits its star tightly enough that if you traveled there, an entire year would only last 18 hours. Its surface is literally an ocean of lava.

And, as if that weren’t enough, this orb doesn’t even circle its star in a flat trajectory.

In our solar system, of course, the planets revolve around the sun in a regular path like the rings around Saturn – a pancake of little kingdoms, although technically ex-planet Pluto is sort of doing its own thing. But Janssen? No. This globe is fully planetary and fully misaligned. For some reason, he mysteriously crosses an alternate plane and even somehow protects himself from our telescopes.

So, unsurprisingly, this super-Earth (it can hold about eight Earths inside) has caught the attention of astronomers around the world.

“55 Cnc e is such an interesting target and dare I say a crowd favourite!” said Lily Zhao, a researcher at the Center for Computational Astrophysics at the Flatiron Institute in New York.

One of many focused on this orb, Zhao and his fellow researchers published a paper in the journal Nature Astronomy on Thursday that appears to answer a glaring question about Janssen. We know it’s incredibly hot and just plain weird, yes, but How? ‘Or’ What has it become the steamy, eccentric place it seems to be today?

Armed with a tool called the Extreme Precision Spectrometer, or EXPRES, they found that the blazing world probably formed a long time ago in a relatively cooler orbit (which was still extremely hot, to be clear), but that it was gradually being pushed towards its star, named Copernicus, due to the gravitational vortices created by the other four planets in the system.

Eventually, Janssen reached where he is right now, sweltering next to beaming star rays and under the microscope of humanity.

Previously, scientists had suggested that the gravity of a nearby red dwarf star, rather than the adjacent planets themselves, was to blame for Janssen’s relocation. However, Zhao explained, “because we find that 55 Cnc has an orbit aligned with the star’s equator, this promotes more dynamically smooth migration paths.”

Nudges from the family, you might say.

Thanks to EXPRES, this is the smallest measure of its kind to date. This means that in the future, the promise of the machine could be limitless.

“EXPRES is part of a generation of instruments designed to be more precise and therefore sensitive to smaller signals, such as those from habitable or even Earth-like planets,” Zhao said. “We are now able to detect signals of the magnitude needed to find Earths elsewhere in the universe, planets that would be hospitable to life.

“Now all that’s left to do is get enough data to find them!”

A weird place for planets

When I first heard about how the Copernicus star system had planets following tracks that didn’t quite match, I’ll be honest, I imagined a bunch of worlds orbiting around it. a star like electrons on Jimmy Neutron’s atomic shirt swirling around a nucleus of protons and neutrons.

The good news here is that maybe I was right.

Although scientists know that Janssen’s four siblings are also not aligned with Copernicus – terrestrial telescopes do not see them crossing between our planet and the star, despite Janssen’s fact – we have not measured their trajectories with enough precision to conclude how they move.

“Since 55 Cnc e is the only transiting planet, it’s the only planet for which measurements like this are possible,” Zhao said. “With astrometric data, we could learn the orientation of other planets relative to 55 Cnc e and use that measurement to anchor the orbital alignments of other planets – but the ability to make such a measurement has yet to be demonstrated. “

The bad news, however, is that I probably wasn’t right.

“From the information we’ve gathered, I think it’s unlikely that the other planets are extremely varied,” Zhao said, explaining how EXPRES found Janssen to be more aligned with his star’s equator. “A highly varied system would more likely be the result of a chaotic process that didn’t allow 55 Cnc e to line up as well.”

Other angles of physics also seem to prove my fantastic theory of the atom incorrectly, such as the fact that so that planets don’t transit between Earth and their star, they don’t really must be very misaligned. They might just be a tiny bit off-road.

“Because they orbit much farther than 55 Cnc e, they actually only have to be slightly misaligned to no longer pass between the star and us, so there is also no strong constraint on the other planet’s orbits that way,” Zhao said. .

Also, in general, star systems tend to form more aligned like ours and merge over time, if at all. That’s because planets usually arise from what’s called a protoplanetary disk of random chunks of gas, dust, rock – whatever, really – that eventually condense into floating spheres.

But gravity has a mind of its own, pushing and pulling at things until it finds a balance to its liking, though that balance may or may not be very different from where the system started.

Luckily, according to Zhao, the solar system already seems to have this special balance, so it probably won’t be pushing Mars skyward and burying Earth underground.

Still, it’s incredibly fascinating to see a wobbly solar system different from our own, highlighting just how different every corner of the universe is bound to be and how quickly they can evolve. And now that we can detect them, it’s all the more interesting.

“It’s exciting to now have this measurement in hand showing that the instrument we built is working and delivering the kind of results we built it for,” Zhao said.