Rare solar system discovered with planets’ orbits in perfectly sync

Astronomers have discovered a rare solar system with six planets that are moving in synchronicity with each other.

The discovery is remarkable, experts say, as it suggests that the newly found solar system has remained undisturbed since it was formed more than four billion years ago.

It has the potential to provide deep insight into how planets form and evolve.

This exoplanet system has a nearly perfect what astronomers call ‘resonance,’ or in mathematically perfect orbits.

An orbital resonance is when two objects orbiting around something else have orbital periods that are simple ratio with each other.

The innermost planet completes three orbits for every two by its closest neighbour, a 3:2 resonance. It’s the same for the second and third-closest planets and the third and fourth-closest planets.

The two outermost planets complete an orbit in 41 and 54.7 days, resulting in four orbits for every three, or a 4:3 resonance. The innermost planet, meanwhile, completes six orbits in exactly the time the outermost completes one.

1 in 100 solar systems left in sync

All solar systems, including our own, are thought to have started like this exoplanet system, according to scientists.

But it’s estimated only one in 100 systems have retained that synchrony, and ours isn’t one of them.

“The reason why this planetary system is therefore interesting is that actually many planetary systems don’t have these orbital resonances,” said Dr Greg Brown, Senior public astronomy officer at the Royal Observatory Greenwich.

“And that’s because, we think that, over time, as the planets are evolving and the solar systems are changing… getting slightly pushed away. So, we end up with a number of planetary systems out there which are close to being an orbital resonance, but few that are actually in these resonances.” Dr Brown added.

While astronomers know of 40 to 50 in-sync solar systems, none have as many planets in such perfect step or as bright a star as this one.

It’s also situated quite near our solar system, 100 light years away from us.

While it may sound vast in cosmic terms, the system is remarkably close to us.

Designated HD 110067, the star is in the Coma Berenices constellation, which sits near Virgo in the northern sky.

Discovered by satellites

The discovery was made possible by a pair of planet-hunting satellites, including NASA’s Transiting Exoplanet Survey Satellite, or TESS.

More observations are needed to determine what’s in their atmospheres, but scientists already believe HD 110067 may have even more planets.

The six found so far are roughly two to three times the size of Earth but they are huddled closer to their host star.

Their orbits are so compact that the entire span could fit within the distance between Mercury and our Sun.

None of the planets are within the star’s so-called habitable zone, which means little if any likelihood of life, at least as we know it for now.

For more on this story, watch the video in the media player above.

Video editor • Roselyne Min