We have detected thousands of exoplanets, but for the most part, no one has ever seen them. It really is just data and graphs of light curves. The exoplanet images you see here on Universe Today and other space websites are the creations of highly skilled illustrators, equal parts data, and creative license. But that is beginning to change.
The Very Large Telescope (VLT) of the European Southern Observatory has captured images of two exoplanets orbiting a young Sun-like star.
These images are part of a study titled “Two Giant Wide Orbiting Planets with Direct Images Around the Young and Solar Analog TYC 8998-760-1”. The lead author is Alexander Bohn, a PhD student at Leiden University in the Netherlands. The research is published in The Astrophysical Journal Letters.
The star is called TYC 8998-760-1. It is about 300 light years away, and although it is similar to our Sun, it is younger; only 17 million years old That means that in some ways, at least, it’s like looking at our Solar System in its younger days.
“Our team has now been able to take the first picture of two gas giant partners orbiting a young solar analog,” co-author Maddalena Reggiani said in a press release. Lead author Bohn added: “This discovery is a snapshot of an environment that is very similar to our Solar System, but at a much earlier stage in its evolution.”
Actual images of exoplanets are very rare, and this is just the third image of two exoplanets orbiting their star, and the first image of two orbiting a Sun-like star. In addition to being a rarity, these images will have scientific significance each time. higher. “Although astronomers have indirectly detected thousands of planets in our galaxy, only a small fraction of these exoplanets have been directly photographed,” said co-author Matthew Kenworthy, an associate professor at Leiden University. He added that “direct observations are important in finding environments that can support life.”
Could these two planets support life? Not likely.
Both planets are giant giants and orbit their star at distances of 160 and 320 AU. These planets are much farther from their star than Jupiter and Saturn from our Sun. Both are also more massive than Jupiter and Saturn, and the closest one has 14 Jupiter masses and the other six Jupiter masses. There is probably a better chance of finding habitable conditions on any moon these two may have, just like some of Jupiter’s moons in our system.
In the images, the host star is in the upper left corner, while the two gas giants line down and to the left. White arrows mark the planets. By taking multiple images of the system at different times, they were able to rule out which points were background stars and which were planets.
ESO’s VLT helped make this discovery with a special instrument called SPHERE, or high contrast spectropoimetric exoplanet search instrument. Direct imaging of exoplanets is extremely difficult, but SPHERE was designed and built for that. Normally, the bright light from a star makes it difficult to see the dark planets that orbit it, but SPHERE’s coronagraph makes it possible.
And future telescopes will be even better at imaging exoplanets. ESO’s Extremely Large Telescope (ELT) should see first light in 2025, and it will be even more powerful than the VLT.
The team learned a few things about these planets from these images. They think circular orbits are relatively stable, but there is chaos on longer time scales. That tells you something about how they formed, and whether there could be other planets not yet seen in the system. In their article, they write: “We showed that the circular orbits are stable, but that the slightly eccentric orbits for either / both components (me > 0.1) are chaotic on gigayear timescales, which implies in-situ training or a very specific expulsion by an invisible third partner. “
Future observations with the ELT or other facilities should confirm the exclusion of the presence of other planets.
“The possibility that future instruments, such as those available in the ELT, can detect even lower-mass planets around this star marks an important milestone in understanding the systems of various planets, with possible implications for the history of our own Solar System, “said lead author Bohn.
In emphasizing that point, the authors write in their article that “these multi-planet systems are intriguing laboratories for studying the dynamic interactions and dispersal events between various companions of planetary mass, which is crucial to understanding the formation and dynamic evolution of planetary systems. “
This system is ripe for further study. In their article, the authors write that this system is a “primary system for further study of the dynamic and chemical properties of two gaseous, two-coefficient, gravitationally bonded planets.”
But to understand more about how they formed, and by extension learn something about how our own Solar System formed, researchers must better constrain the orbits of the two planets. “Continuous astrometric monitoring will limit the orbital solutions for both partners, and therefore allow testing of possible formation scenarios.”
The powerful SPHERE instrument made these images possible. But even SPHERE has its limitations. Its coronagraph is capable of blocking bright light from the star and making dark planets visible. Unfortunately this only works in younger solar systems like this. In some like ours, the planets are too cold to be seen. Young planets in this system are hotter, making them brighter in the infrared, making them visible.
