The ESA’s Gaia mission is our most accurate star-measuring spacecraft. It’s busy mapping the positions and radial velocities of one billion stars in the Milky Way. The mission’s goal is to create a representative map of the galaxy’s stellar population with unprecedented accuracy. The mission has released 3 sets of data since its inception, leading to many discoveries.
Now a team of astronomers has found an exoplanet with help from Gaia, an unintended result of the ambitious mission.
The massive Kepler survey found a treasure trove of exoplanets. But in all that wealth they found three anomalies: what appeared to be rings of dust surrounding stars where planets should be. They were rocky planets in the process of being obliterated. And a team of astronomers that found a way to use these gory sites to understand some of the most mysterious and hard to detect planets in the universe.
There’s an interesting problem in exoplanet studies: how to tell if a planet has a magnetosphere. It’s not like we can visibly see it unless we find a different way of looking. A pair of scientists may have found one. They used radio telescopes to track emissions given off by magnetic star-planet interactions. These happen when a planet with a magnetic field plows through star stuff caught its star’s magnetic field.
With the James Webb Space Telescope’s ability to detect and study the atmospheres of distant planets orbiting other stars, exoplanet enthusiasts have been anticipating JWST’s first data on some of the worlds in the famous TRAPPIST-1 system. This is the system where seven Earth-sized worlds are orbiting a red dwarf star, with several in the habitable zone.
Today, a new study was released on the innermost planet in the system, TRAPPIST-1 b. The authors of the study were quite frank: this world very likely has no atmosphere at all. Additionally, the conditions there for possible life as we know it only get worse from there.
1800 light-years away, an unlikely survivor orbits an aged star. This rare planet is called a hot Neptune, and it’s one of only a small handful of hot Neptunes astronomers have found. Hot Neptunes are so close to their stars that the overpowering stellar radiation should’ve stripped away their atmospheres, leaving only a planetary core behind.
As tragic as it is, engulfment of a planetary object by its stellar parent is a common scenario throughout the universe. But it doesn’t have to end in doom. A team of astrophysicists have used computer simulations to discover that planets can not only survive when their star eats them, but they can also drive its future evolution.
We’re lucky to have a neighbour like Venus, even though it’s totally inhospitable, wildly different from the other rocky planets, and difficult to study. Its thick atmosphere obscures its surface, and only powerful radar can penetrate it. Its extreme atmospheric pressure and high temperatures are barriers to landers or rovers.
It’s like having a mysterious exoplanet next door.
As of this writing, almost 5300 exoplanets spanning approximately 4000 planetary systems have been confirmed to exist in our universe. With each new exoplanet discovery, scientists continue to learn more about planetary formation and evolution that has already shaken our understanding of this process down to its very core. One such example is “Hot Jupiters”, which are Jupiter-sized exoplanets, or larger, that orbit closer to their parents stars than Mercury does to our own. This is in stark contrast to our own Solar System, which has rocky planets closer towards our Sun and the gas giant planets much farther out.
In this era of exoplanet discovery, astronomers have found over 5,000 confirmed exoplanets, with thousands more awaiting confirmation and many billions more waiting to be discovered. These exoplanets exist in a bewildering spectrum of sizes, compositions, orbital periods, and just about every other characteristic that can be measured.
Learning about them has also shed light on our Solar System. We used to think of it as an archetypal arrangement of planets since it’s all we had to go on. But now we know we might be the outlier because we have no Super-Earth.