Each of these stars is unique, but the system around the star HD 158,259, 88 light-years away, is actually the most unique.
Scientists note that this star, which has the same mass of the sun and is slightly larger than it, is from the minority that has been observed from exoplanets. Six planets revolve around it: a super Earth and five small Neptune planets.
After observing it for seven years, astronomers discovered that all of these six planets revolve around HD 158,259 in an almost perfect orbital echo.
This discovery can help us better understand the mechanisms of planetary system formation, and how they end up in the formations we see.
This movement is known as “orbital resonance,” which occurs when two rotating objects have a periodic, gravitational effect on each other. In the solar system, orbital resonance is very rare in planetary bodies, and perhaps the best example of this is Pluto and Neptune.
Scientists have identified orbital resonance in the outer planets. And they found that each planet orbiting HD 158,259 is in a ratio of about 3: 2, with the next planet, described by 1.5, exiting, meaning that while the first planet, closest to the star, completes three orbits, the second completes about two. While this second planet completes three orbits, the third completes about two, and so on.
Using the measurements taken by the SOPHIE spectroscope and the TESS space telescope, an international team of scientists, led by astronomer Nathan Hara, from the University of Geneva in Switzerland, managed to accurately calculate the orbits of each planet, as follows: 2.17, 3.4, 5.2, and 7 .9, 12 and 17.4 days.
These orbits produce orbital resonance ratios of: 1.57, 1.51, 1.53, 1.51, and 1.44 among each pair of planets. This isn’t quite a perfect ring, but it’s close enough to classify the HD 158259 as an exceptional system.
Scientists believe this is a sign that the planets orbiting the star have not formed in their current location.
Source: Russia Today