The star HD 158259 is almost visible to the defenseless eye in the Draco constellation 88 light - years from Earth . Nothing special so far . What makes the star challenging is that it is surrounded by six major planet . Only 12 other systems have this many or more orbiting a hotshot . Not only that but the orbit of the planet have a specific rhythm .
The planets are said to be in almost 3:2 resonance . This means that for every three orbits of the innermost satellite , the second inmost one make out two orbits . And for every three ambit of the second , the third does two , and so on .
“ This is like to several musicians beating decided rhythms , yet who pose at the same metre at the beginning of each bar , ” first writer Nathan C. Hara , from the University of Geneva , said in astatement . The findings are publish in the journalAstronomy & Astrophysics .
Resonance , which has been seen in other multi - planetary system such asTRAPPIST-1 , may be primal to preserve certain systems stable . In these systems , satellite spring far aside from the star topology and then move nigher and close due to their interaction with the disc of material from which they formed . Where multiple planets are concerned , these migration may end up knocking a major planet into a star or another planet , or kick back - it outside the system . But if the major planet get locked in a resonance , it ’s possibletheir migration may stay on stable .
The team believe the six satellite must have moved closer to HD 158259 by staying in resonance and only afterwards did they bulge out depart from perfect concordance . The planets are only inabouta 3:2 resonance . The squad are intrigued by what this info can tell us .
“ Here , ' about ' is significant . Besides the omnipresence of the 3:2 full point proportion , this constitutes the originality of the system , ” excuse Hara . “ Furthermore , the current departure of the period ratios from 3:2 contain a wealth of entropy . With these values on the one hand and tidal effect models on the other , we could stiffen the inner structure of the planets in a future written report . In summary , the current state of the organization gives us a window on its shaping . ”
Using the SOPHIE spectrograph establish at the Haute - Provence Observatory in the South of France , the squad measure the properties of the system . Five of the planets are mini - Neptunes with a quite a little of about six times our planet . The innermost was valuate withplanet - hunting scope TESSand has a sight of about two Earths .
