I want you to picture the two kinds of planets that we know about in the universe.
Solid rock-like planets, and then gas giants.
You know that both of them have cores, right?
One is molten (or so we believe we can't actually prove this without samples) and one is believed
to be a compressed gas core.
But, as noted, it's really hard to prove these without actually going to the core and seeing
it for ourselves.
That is...until potentially right now, for one of these types of planets anyways.
A distant world about 40 times more massive than Earth may be the remnant core of a giant
planet, or a giant planet in the making whose growth stalled, a new study reports.
These findings may help shed light on what the mysterious cores of giant planets look
like, researchers said.
Which would obviously be a BIG step towards not just researching planets, but understanding
how they form, how they continue to live, and of course, what happens when they die.
Scientists investigated the exoplanet TOI-849b, which NASA's Transiting Exoplanet Survey Satellite
(TESS) first detected in 2018 and whose existence the La Silla Observatory in Chile later helped
confirm.
This alien world orbits the sunlike star TOI-849 about 730 light-years from Earth.
With a mass about 40 times that of Earth, TOI-849b is nearly half as massive as Saturn.
At the same time, data from the Paranal Observatory in Chile and the Las Cumbres Observatory Global
Telescope helped reveal that the exoplanet has a diameter about 3.45 times that of Earth,
comparable to Neptune's.
Altogether, this information suggests the exoplanet has a density similar to Earth's,
making it the densest Neptune-size planet discovered to date.
Which is quite a feat given all the planets that have been discovered in recent years
from various telescopes, satellites, probes, and more.
TOI-849b circles its star in a fast, tight orbit just 18.4 hours long.
This brings it scorchingly close to its star at a distance of just 1.5% of an astronomical
unit (AU), the average distance between Earth and the sun (which is about 93 million miles,
or 150 million kilometers).
The newfound exoplanet therefore lies in the middle of the so-called "hot Neptunian desert,"
an apparent (and mysterious) dearth of Neptune-size worlds that orbit very close to their stars.
"There are not a lot of planets in this in-between place, so to see a planet this size this close
to a star is pretty cool," Sean Raymond, an astrophysicist at the Observatory of Bordeaux
in France, who did not take part in this research, told Space.com.
Cool indeed, except when you're the planet being scorched by the sun, but we're pretty
sure it doesn't have feelings.
Still, seen a massive ball of gas like this be so close to its sun raises a lot of questions
and wonders, which is why many scientists are very focused on this exoplanet.
Especially since the very existence of TOI-849b contradicts what many people think happen
with gas giants depending on their size.
Previous models suggested that nascent planets more than 10 to 20 times Earth's mass should
have strong enough gravitational fields to gobble up huge amounts of material from the
protoplanetary disks of gas and dust that surround their newborn stars.
Such worlds
should therefore swell to become gas giants similar to Jupiter or Saturn.
As such, one might think that TOI-849b is the remnant of a gas giant that lost most
of its weight somehow, perhaps due to the heat it experiences orbiting so close
to its star.
If this is true, this would create a whole new path for certain planets to go depending
on their circumstances, and if this is the core of a former gas giant, it would be treated
in a whole other way.
However, as much as the light from TOI-849b's star would sear the exoplanet, the scientists
noted such heating alone might still not strip a gas giant's atmosphere down to nearly the
planet's core.
They estimated the star is about 6.7 billion years old.
Given that amount of time, as well as TOI-849b's distance from its star, they calculated a
Jupiter-like gas giant would have lost only a few percent of its mass due to stellar radiation
to date.
Granted, this is just based on calculations and is not hard proof, but these models do
seem to point to this not being a planet ravaged by a star (or at least this star its orbiting),
and it's fair to believe that.
For now at least, because if more evidence or proof comes to life, it would obviously
change things.
As such, the researchers suggest that TOI-849b may be the remnant core of a gas giant that
lost mass through a different mechanism.
Perhaps it collided with other giant planets, for example, or the gravity of its star peeled
off much of its gas envelope.
Alternatively, if TOI-849b were slung to
its current position due to gravitational clashes with other planets, the energy the
exoplanet would have experienced as its star's gravity pulled TOI-849b into its current circular
orbit would have greatly heated that world, potentially leading to significant mass loss.
You might think, "Wait a minute, since when can stars be slung through the universe?"
Believe it or not, this happens a lot more than you think.
You see, many things in the universe, even stars, are tethered to something.
Planets are usually tethered to stars (like Earth with our own sun) and stars are tethered
to the greater gravitational forces of the galaxy they're in.
That's how orbits are made.
But, at times, these orbits are disrupted, and it lead to planets being flung from their
orbits and put into space at blinding speed (these are known as Rogue Planets, and many
exist in the universe) and of course, if done properly, stars could have this done to them
to.
And these planets
and stars don't stop until they've collided with something, or get caught by a
strong gravity.