Over the past decades, ground-based and orbiting observatories have discovered thousands of exoplanets of various sizes. Some of them look like Earth, others look like giant planets like Jupiter. Most of these objects orbit their parent star, either alone or together with several neighboring stars. The discovery of a planetary system with seven planets is a real rarity for astronomers.
In 2018, after 9 years of space exploration, the “exoplanet hunter” – the Kepler orbiting telescope – completed its mission. During its operation, the instrument discovered nearly 4.5 thousand exoplanet candidates, of which about 2.5 thousand candidates were confirmed.
The space observatory has been searching for exoplanets using transit photometry. This method is based on observing the movement of a planet relative to the background of its parent star. The telescope has collected so much information that scientists continue to study it. Often, its analysis leads to discoveries. For example, in 2020, astronomers discovered 17 new candidate exoplanets in Kepler data. Today, a team of astronomers from NASA’s Ames Research Center, USA, made another discovery through analyzing data from a space telescope. Researchers have described a system of seven planets orbiting the star Kepler 385, at a distance of 4.6 thousand light years from Earth. This planetary system is described in the updated catalog of Kepler planet candidates: focusing on precision and orbital period, published in the Journal of Planetary Science. It is currently available on the electronic preprint archive arXiv.
Scientists knew about the star Kepler 385 and the exoplanet Kepler-385 b (at a distance of 0.097 AU) orbiting it in 2014. However, in new research, astronomers have confirmed the discovery. presence of other exoplanets around the star: so it turns out. there are only seven of them. Additionally, in the updated catalog, researchers revealed new details about the star itself. The star Kepler 385 is similar to the Sun but is 10% larger and about 5% hotter. It belongs to spectral class F, has a yellow-white color and a surface temperature of 6 to 7.5 thousand kelvin. The star is surrounded by seven exoplanets, larger than Earth but smaller than Neptune. Two of them are located inside – most likely “super-Earths”, rocky worlds with thin atmospheres. The remaining five are external, they are a little larger. Each has a radius twice that of Earth (Earth’s radius is 6,371 km). Perhaps, they are enveloped in a dense atmosphere.
Astronomers concluded that the seven exoplanets, although located in the so-called habitable zone, are probably inhospitable to life. They lie very close to their parent star and are literally “bathed” in intense radiation. These objects receive more heat per unit area than any planet in the solar system. The Kepler 385 planetary system is of great interest to astronomers. This is one of the few known systems to contain more than six planets. Another famous example is TRAPPIST-1. Further observations of Kepler 385 will allow scientists to better understand how planets of different masses and sizes interact with each other and what their physical properties are. Note that detecting planets is made even more difficult by their long orbital periods, as distant planets rarely pass between their star’s disk and an observer on Earth. Therefore, in reality, there may be many more multi-planetary systems than today’s scientists think.