We know of hundreds of photo voltaic programs, however none like this one. After a number of years of labor and observations with terrestrial and area telescopes, a global group of astronomers right this moment describes the system LHS 1903, a purple dwarf star by which 4 planets have been found whose association defies all present bodily fashions.
“This system does not fit with anything we knew until now; it is disordered,” astronomer Ignasi Ribas, co-author of the invention, acknowledges to this newspaper, which is revealed this Thursday within the journal Science.
This purple dwarf star, essentially the most considerable sort of star within the identified universe, though not seen to the bare eye within the night time sky, is dwelling to the primary rocky planet like Earth. Then there are two planets of intermediate measurement which have vital gaseous envelopes, just like the planet Neptune, though considerably smaller. Until then every part is regular. The new factor—the one factor—is that past the third gaseous planet there’s a fourth world that’s as soon as once more rocky and just like Earth.
It is one thing by no means seen among the many greater than 6,000 exoplanets and nearly 4,500 photo voltaic programs found to this point. The principle says that planets kind from a big disk of mud and fuel that surrounds stars of their preliminary phases of life. Until now, the universe appeared to comply with very particular guidelines when forming planetary programs that coincide with the group of our personal photo voltaic system. The planets closest to the star are normally rocky—Mercury, Venus, Earth and Mars—primarily as a result of the Sun’s warmth prevents the focus of icy gases. The most distant planets would additionally kind from rocky cores, however as a result of their distance they will accumulate many extra gases till they’re 10 occasions bigger than Earth and 300 occasions extra huge, like Jupiter.
The star LHS 1903 is about 120 gentle years away, a distance not very far in cosmological phrases, however equal to greater than 1,000 trillion kilometers, one thing unattainable for any spacecraft. Its first three planets have been detected by NASA’s Tess area telescope and confirmed with a number of ground-based observatories in Mexico, the Canary Islands or the American island of Hawaii, between 2019 and 2023. Subsequently, the Cheops area telescope, of the European Space Agency, made some confirmatory observations. It was then that the existence of the fourth planet was found. It is a world with a radius 1.7 occasions that of the Earth and a mass about six occasions higher, “which implies that its density is very similar to that of our planet,” explains Ribas, director of the Institute of Space Studies of Catalonia and researcher on the CSIC.
The authors of the invention – a gaggle of greater than 150 astronomers from 17 international locations – imagine that the probably clarification is that this final world shaped in an setting with out gases and in a later interval than the remaining. This implies that on this photo voltaic system there have been two planetary genesis, one thing by no means seen earlier than. “The three inner planets have formed before and have been enriched in gas when possible, and the outer one would have appeared a few million years later,” causes Ribas.
The discovery could open the eyes of humanity to prospects that had not been contemplated till now. “There is especially great interest in understanding the architecture of planetary systems,” explains Ribas. “It’s this transition between gas-rich planets and poor planets. This is what separates the planets that have large gas envelopes [la inmensa mayoría de los descubiertos hasta ahora]of those that have a non-existent or very small gas envelope, such as our own Earth, since its atmosphere is really very small compared to that of the gas giants. This system is especially good for understanding where that limit is, that transition,” he adds.
This discovery “is a bombshell,” summarizes José Caballero, a researcher at the Astrobiology Center, near Madrid. “In none of the more than 6,000 known exoplanets did we have evidence that any had formed after their companions,” highlights the researcher, who has not participated in the study. In theory, all the planets form at the same time from the large protoplanetary disk where the planets appear at the same time.
The LHS 1903 system is also unique in another way. Most of the stars around which numerous groups of planets have been found, such as Trappist, with up to seven Earths, or Teergarden, with four, are like “pea pods,” because all the planets have a similar composition and size, explains Caballero. “In this case we’d be seeing a pod by which we surprisingly discovered two peas within the heart and two lentils on the ends, which might be the terrestrial planets. This breaks all our schemes,” acknowledges the researcher.
The pod simile also exemplifies another characteristic of the solar systems of red dwarf stars, smaller and more unstable than the Sun: their planets are much closer to their star, which complicates their chances of hosting life. The period of the four worlds of LHS 1903—the time they take to complete a return to their star—ranges from two days in the case of the closest planet, to 29 for that fourth terrestrial body that seems out of place. The last planet in this system, named briefly with the letter e, has a surface temperature of about 60 degrees, probably too much to support life, Ribas acknowledges.
This discovery comes on the proper time, as this week there’s a assembly in Holland to determine whether or not to increase the helpful lifetime of the Cheops area telescope for one more three years.
https://elpais.com/ciencia/2026-02-12/descubierto-un-sistema-solar-con-dos-tierras-en-un-orden-nunca-visto.html