Astronomers discover a rhythmic family of six exoplanets | CNN (2024)

Astronomers discover a rhythmic family of six exoplanets | CNN (1)

The orbits of the six planets revolving around a star called HD110067 create a geometric pattern due to their resonance.

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Astronomers have used two different exoplanet-detecting satellites to solve a cosmic mystery and reveal a rare family of six planets located about 100 light-years from Earth. The discovery could help scientists unlock the secrets of planet formation.

The six exoplanets orbit a bright star similar to the sun named HD110067, which is located in the Coma Berenices constellation in the northern sky. Larger than Earth but smaller than Neptune, the planets are in a little-understood class called sub-Neptunes commonly found orbiting sunlike stars in the Milky Way. And the planets, labeled b through g, revolve around the star in a celestial dance known as orbital resonance.

There are discernible patterns as the planets complete their orbits and exert gravitational forces on one another, according to a study published Wednesday in the journal Nature. For every six orbits completed by planet b, the closest planet to the star, the outermost planet g completes one.

As planet c makes three revolutions around the star, planet d does two, and when planet e completes four orbits, planet f does three.

This harmonic rhythm creates a resonant chain, with all six planets aligning every few orbits.

What makes this planetary family an unusual find is that little has changed since the system formed more than 1 billion years ago, and the revelation could shed light on the evolution of planets and the origin of prevalent sub-Neptunes in our home galaxy.

Detecting a mystery

Researchers first took notice of the star system in 2020 when NASA’s Transiting Exoplanet Survey Satellite, or TESS, detected dips in the brightness of HD110067. A dip in starlight often suggests the presence of a planet that’s passing between its host star and an observing satellite as the planet travels along its orbital path. Detecting these dips in luminosity, known as the transit method, is one of the main strategies used by scientists to identify exoplanets via ground and space-based telescopes.

Astronomers determined the orbital periods of two planets around the star from that 2020 data. Two years later, TESS observed the star again, and the evidence suggested different orbital periods for those planets.

When the data sets didn’t add up, astronomer and lead study author Rafael Luque and some of his colleagues decided to take another look at the star using a different satellite — the European Space Agency’s CHaracterising ExOPlanet Satellite, or Cheops. While TESS is used to observe fractions of the night sky for short observations, Cheops observes one star at a time.

Astronomers discover a rhythmic family of six exoplanets | CNN (2)

This artist's illustration shows Cheops in orbit around Earth as it searches for exoplanets.

“We went fishing for signals among all the potential periods that those planets could have,” said Luque, a postdoctoral scholar in the University of Chicago’s department of astronomy and astrophysics.

The data collected by Cheops helped the team solve the “detective story” started by TESS, he said. Cheops was able to determine the presence of a third planet in the system, which was crucial to confirming the orbital periods of the other two planets, as well as their rhythmic resonance.

As the team matched up the rest of the unexplained TESS data with the Cheops observations, they discovered the other three planets orbiting the star. Follow-up observations with ground-based telescopes confirmed the presence of the planets.

The dedicated time Cheops spent observing the star helped astronomers iron out the mixed signals from the TESS data to determine how many planets were crossing in front of the star and the resonance of their orbits.

“Cheops gave us this resonant configuration that allowed us to predict all the other periods. Without that detection from Cheops, it would have been impossible,” Luque said.

The closest planet takes just over nine Earth days to complete an orbit around the star, and the most distant takes about 55 days. All of the planets have quicker revolutions around their star than Mercury, which takes 88 days to complete one lap around the sun.

Given how close they are to HD110067, the planets likely have blistering average temperatures similar to Mercury and Venus, ranging between 332 degrees Fahrenheit and 980 degrees Fahrenheit (167 degrees Celsius and 527 degrees Celsius).

Why planetary rhythm matters

The formation of planetary systems, like our own solar system, can be a violent process. While astronomers believe that planets tend to initially form in resonance around stars, the gravitational influence of massive planets, a graze with a passing star or a collision with another celestial body can upset the harmonic balance.

Most planetary systems are not in resonance, and those with multiple planets that have preserved their initial rhythmic orbits are rare, which is why astronomers want to study HD110067 and its planets as a “rare fossil” in detail, Luque said.

This artist's concept shows what the exoplanet WASP-17 b could look like.WASP-17 b, also called Ditsö̀, is a hot gas giant that orbits its star at a distance of just 0.051 AU (about 4.75 million miles, or one-eighth the distance between Mercury and the Sun), completing one full circuit in about 3.7 Earth-days. The system lies within the Milky Way, about 1,300 light-years from Earth, in the constellation Scorpius.With a volume more than seven times that of Jupiter and a mass less than one-half of Jupiter, WASP-17 b is an extremely puffy planet. Its short orbital period, large size, and thick, extended atmosphere make it ideal for observation using transmission spectroscopy, which involves measuring the effects of the planet's atmosphere on the starlight filtering through it.WASP-17 b's atmosphere is composed primarily of hydrogen and helium, along with small amounts of water vapor and hints of carbon dioxide and other molecules. Observations of 5- to 12-micron infrared light from Webb's MIRI (Mid-Infrared Instrument) show that WASP-17 b's atmosphere also contains clouds made of nanocrystals of quartz (SiO2).WASP-17 b is tidally locked and has a retrograde orbit. Its temperature ranges from about 1,000 kelvins (1,350 degrees F or 725 degrees C) on the cooler nightside to nearly 2,000 kelvins (3,150 degrees F or 1,725 degrees C) on the side in permanent daylight.The star, WASP-17 (also called Diwö), is an F-type star: slightly larger, more massive, hotter, and whiter than the Sun.This artist's concept is based on new data gathered by MIRI as well as previous observations from other ground- and space-based telescopes, including NASA's Hubble and retired Spitzer space telescopes. Webb has not captured any images of the planet. NASA, ESA, CSA, Ralf Crawford (STScI) Quartz crystals detected swirling in an exoplanet’s atmosphere

“We think only about one percent of all systems stay in resonance,” Luque said in a statement. “It shows us the pristine configuration of a planetary system that has survived untouched.”

The discovery is the second time Cheops has helped reveal a planetary system with orbital resonance. The first one, known as TOI-178, was announced in 2021.

“As our science team puts it: Cheops is making outstanding discoveries sound ordinary. Out of only three known six-planet resonant systems, this is now the second one found by Cheops, and in only three years of operations,” said Maximilian Günther, ESA Cheops project scientist, in a statement.

A perfect observation target

The system can also be used to study how sub-Neptunes form, the study authors said.

While sub-Neptunes are common in the Milky Way galaxy, they don’t exist in our own solar system. And there is little agreement among astronomers about how these planets form and what they’re made of — so an entire system consisting of sub-Neptunes could help scientists determine more about their origin, Luque said.

Many exoplanets have been found orbiting dwarf stars that are much cooler and smaller than our sun, such as the famed TRAPPIST-1 system and its seven planets, announced in 2017. While the TRAPPIST-1 system also has a resonant chain, the faintness of the host star makes observations difficult.

exoplanet K2-18 b illustration NASA/ESA/CSA/Joseph Olmsted (STScI) Planet in ‘habitable’ zone could have rare oceans and a possible sign of life, Webb data reveals

But HD110067, which has 80% the mass of our sun, is the brightest known star with more than four planets in orbit, so observing the system is much easier.

Initial detections of the mass of the planets suggest that some of them have puffy hydrogen-rich atmospheres, which makes them ideal targets of study for the James Webb Space Telescope. As starlight filters through the planets’ atmospheres, Webb can be used to determine the composition of each world.

“The sub-Neptune planets of the HD110067 system appear to have low masses, suggesting they may be gas- or water-rich. Future observations, for example with the James Webb Space Telescope, of these planetary atmospheres could determine whether the planets have rocky or water-rich interior structures,” said study coauthor Jo Ann Egger, doctoral student in astrophysics at the University of Bern in Switzerland, in a statement.

Astronomers discover a rhythmic family of six exoplanets | CNN (2024)


Astronomers discover a rhythmic family of six exoplanets | CNN? ›

The six exoplanets orbit a bright star similar to the sun named HD110067, which is located in the Coma Berenices constellation in the northern sky. Larger than Earth but smaller than Neptune, the planets are in a little-understood class called sub-Neptunes commonly found orbiting sunlike stars in the Milky Way.

Have astronomers discovered a new six planet solar system? ›

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago. The find, announced Wednesday, can help explain how solar systems across the Milky Way galaxy came to be.

Is there a solar system with 6 planets? ›

Astronomers have discovered a rare solar system with six planets moving completely in sync with one another, a perfect cosmic dance. Estimated to be billions of years old, the formation 100 light years away may help unravel some mysteries of our solar system. Science correspondent Miles O'Brien joins us now.

How many exoplanets have astronomers found? ›

To date, more than 5,000 exoplanets have been discovered and are considered "confirmed" out of the billions in our galaxy alone. There are thousands of other "candidate" exoplanet detections that require further observations in order to say for sure whether or not the exoplanet is real.

Did astronomers discover six planets orbiting a nearby sun like star? ›

One hundred light years away, a handful of planets are circling a star in the same configuration as when they formed. Astronomers have discovered six planets orbiting a bright star in perfect resonance. The star system, 100 light-years from Earth, was described on Wednesday in a paper published in the journal Nature.

Who discovered 6 planets? ›

Study led by UChicago astronomer Rafael Luque may tell us about how planets form. Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat.

What is the new planet called in 2024? ›

March 14, 2024

The new planets are HS Psc b, LHS 1678 d, TOI-1994 b, and TOI-4515 b. Click on their names to go directly to their System Overview pages, or browse all system parameters in the archive (including this week's new sets) with the Planetary Systems and Planetary Systems Composite tables.

What is the 6th solar system? ›

Saturn is the sixth planet of the solar system. It is the second largest planet. Saturn has a prominent ring system made of many small ringlets.

Do we have 7 planets in our solar system? ›

The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mercury is closest to the Sun. Neptune is the farthest.

What are the 6 planets in astrology? ›

What planet is associated with Number 6? Venus is the ruling planet of Number 6 people.

Has NASA found a habitable planet? ›

A new "super-Earth" has been discovered in a nearby solar system's habitable zone, according to NASA. The planet, designated as TOI-715 b, is "about one and a half times as wide as Earth" and in a system that is only a measly 137 light-years from Earth.

Are exoplanets rarer than stars? ›

Most of the exoplanets discovered so far are in a relatively small region of our galaxy, the Milky Way. We know from NASA's Kepler Space Telescope that there are more planets than stars in the galaxy.

How many exoplanets are habitable? ›

The Habitable Exoplanets Catalog is also a great resource and currently lists 63 known potentially habitable exoplanets. Twenty-three of those are Earth-sized. Bottom line: Meet Wolf 1069 b, an Earth-size exoplanet only 31 light-years away that resides in its star's habitable zone.

Is there a new planet that looks like Earth? ›

The planet dubbed TOI-715 b, which is about 1½ times as wide as Earth, is just the latest exoplanet astronomers have observed and theorized could support life. The same system where an international team of scientists observed the planet also might harbor a second, Earth-sized planet, NASA said in a news release.

What planet was recently discovered? ›

The recently discovered super-Earth, TOI-715 b, might be making its appearance at just the right time. Its parent star is a red dwarf, smaller and cooler than our Sun; a number of such stars are known to host small, rocky worlds.

What new planet did the astronomers recently discover? ›

The large planet in the foreground is the newly discovered GJ 581g, which has a 37-day orbit right in the middle of the star's habitable zone and is only three to four times the mass of Earth, with a diameter 1.2 to 1.4 times that of Earth.

Did NASA discover a new planet? ›

A new "super-Earth" has been discovered in a nearby solar system's habitable zone, according to NASA. The planet, designated as TOI-715 b, is "about one and a half times as wide as Earth" and in a system that is only a measly 137 light-years from Earth.

Is there a new planet in our solar system? ›

Caltech researchers have found mathematical evidence suggesting there may be a "Planet X" deep in the solar system. This hypothetical Neptune-sized planet orbits our Sun in a highly elongated orbit far beyond Pluto.

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