Taking pictures of exoplanets is tricky work. Not only do you have to get the image when the planet is on the right side of the star, but there is also a ton of light washing out the planet. This has led to new imaging techniques and computer algorithms to cancel out the glare and spot the planet. Viewing planets through infrared helps because of contrasting temperatures between the star and the planet.
Over the last few weeks a couple of papers have come out describing three exoplanets that have been imaged directly. This is a relatively rare occurrence, as these planets bring the total to about 15, which makes these announcements that much more exciting. Interestingly, t all of these planets are pretty young and some are even still forming!
ROXs 12 b is about 390 light years away. It orbits a cool red dwarf at an incredible distance of 20 billion miles (31 billion kilometers), which is about 215 times the Earth's distance from the sun. This planet is incredibly huge, approximately 12-20 times the size of Jupiter. If it is over 13 times the mass of Jupiter, it crosses into “brown dwarf” status, which means it wouldn’t really count as an exoplanet anymore. Astronomers were also able to see a disk around it, meaning it is probably still collecting debris and increasing in mass. We’ll just have to wait and see for more precise measurements.
ROXs 42B b has an estimated mass of 6-15 times that of Jupiter, so there is a chance that this could also be a brown dwarf and not a planet, but it has enough wiggle room to be described as an exoplanet for now. Like ROXs 12 b, ROXs 42B b is also around 390 light years away. The planet orbits binary stars from a distance of 14 billion miles (22 billion kilometers). The planet is exceptionally hot at 3400° F (1900°C).
FW Tau b is ike ROXs 12b in that it orbits binary stars, though it does so from much farther away. It is about 300 AU away from the stars, making it the most distal planet on the list. It also has detectable hydrogen, indicating it is has a disk of debris it is still incorporating into itself. Because it is still forming, it has an approximate temperature of 3000° F (1700° C).
Astronomers have come a long way in recent years in regards to imaging and understanding exoplanets. Even though two of these new discoveries might end up being brown dwarves instead of planets, it is still an incredible accomplishment that they were imaged directly. It’s exciting to think about what we will be able to learn about these exoplanets in the coming years as the technology continues to progress.