Since the first exoplanet discovery in the 1990s, astronomers have found more than 5,500 exoplanets. The Kepler mission, which has been inactive for several years, made the majority of these discoveries possible. But researchers continue to find valuable information in the data it returns. Astronomers from the University of Nevada (USA) have just published a new catalog of exoplanets discovered by the Kepler mission, a catalog they don’t hesitate to call “ultimate.” It lists nearly 4,400 exoplanets, some of which orbit alone around a star, while others are part of more than 700 multi-planet systems. It provides details on the characteristics, such as their orbital period or size, of all these distant planets.
Seven peculiar exoplanets, all within 5,000 light-years of Earth
Especially interesting are those in the system called Kepler-385. Some of these had been confirmed as early as 2014. Today, it falls into the category of rare known systems composed of more than six planets orbiting a single star, located approximately 4,670 light-years from our planet.
The star is only 10% larger than our Sun and about 5% hotter. It hosts seven planets, all larger than Earth but smaller than Neptune. These planets are so close to their stars that each one is bathed in more heat than any in our Solar System. They orbit their star for a period ranging from 10 to 30 days.
The two closest planets to their star are barely larger than our Earth, likely rocky planets, possibly with a thin atmosphere. The other five have a radius that is twice as large as our Earth’s and most likely have a thick atmosphere surrounding them.
Studying Exoplanets to Learn More About Our Solar System
“By studying these distant planetary systems, we get a better sense of our own history and how it diverges from the histories of these other systems. In some way, our Solar System has managed to avoid forming a planetary system like those revealed by the Kepler mission,” notes Jason Steffen, an astrophysicist, in a statement from the University of Nevada. “And if it had, we wouldn’t be here.“
To provide these details and create a comprehensive catalog of planetary systems, the researchers relied on data recorded by Kepler before its “end of life.” They processed the data differently from previous methods to calculate the orbits of each planet. “Preserving this data is very useful, especially as it is probably the best data we will have on these types of planetary systems for decades to come,” concludes Jason Steffen.