SCIENCE: The lost twin of our sun.
Maybe there were two suns in the past. Image by Adina Voicu from Pixabay

The bright star that sits at the center of our planetary system appears and lurks on Earth’s horizon and illuminates the planet during the day, reigning as a clearly solitary star, but could it be that at some point it is accompanied by another twin sun? ?

A team of American researchers considers it a plausible hypothesis that two suns illuminated our planetary system in the very distant past, since our now solitary Sun could have started its life with a companion star, forming a binary system, composed of two stars with characteristics Similar.

A new theory from Harvard University scientists suggests that the Sun could have had a binary companion of similar mass, reports the Harvard & Smithsonian Center for Astrophysics or CfA (, based in Cambridge (Massachusetts, USA)

They say if the theory that the Sun had an early stellar companion is confirmed, it could shed new light on how the “Oort Cloud”, a spherical assembly of billions of small astronomical bodies, such as asteroids and comets, formed. would be located at the edge of the solar system, according to the scientific evidence gathered so far.

Confirmation of the binary theory would also strengthen the likelihood that the hypothetical “Planet Nine” (a ninth large icy planet believed to be located beyond Neptune’s orbit) has been “captured” by the solar system’s gravitational pull. , instead of training within the said system, according to the CfA.


Science professor Avi Loeb, Ph.D., and Harvard undergraduate student Amir Siraj, postulate that the existence of a long-lost stellar binary companion in the Sun’s natal cluster – the set of stars that formed with the Sun from the same dense mass of molecular gas – could explain the formation of the Oort cloud. This binary star would have had a mass similar to that of the Sun, and would have been lost before the Sun never leaves its natal cluster, according to Harvard researchers.

“The birth cluster is the set of stars that formed together with the Sun from the same dense cloud of molecular gas. It looks like a family in which many children are born and then disperse,” says Dr. Abraham (Avi) Loeb at EFE.

“Star clusters often scatter when the gas that formed them is carried away by stellar winds or because they are torn apart by the gravitational pull of the tidal pull of the Milky Way galaxy,” he says.

They explain that a popular theory associates the Oort cloud with remnants of the formation of the solar system and other nearby systems, in which celestial objects were dispersed over great distances and some of these bodies became part of planetary sets different from this one. of which they are the origin.

The binary model proposed by Harvard could be the missing piece of this puzzle, according to Siraj. In fact, there is evidence that most Sun-like stars are born with binary companions and that binary systems are much more efficient at capturing objects than single stars, the researchers say.

If the Oort cloud were indeed captured with the help of an early stellar companion to the Sun, the implications for our understanding of the formation of the solar system would be significant.

X-ray photo of the Sun from the SDO observatory. NASA picture


Rather than redefining the formation of our solar system, confirming that the Oort cloud was captured with the help of one of the Sun’s earliest stellar companions could answer questions about the origins of life on Earth, according to Dr. Loeb.

“Objects in the outer Oort Cloud may have played important roles in Earth’s history, such as possibly providing water to Earth and causing the extinction of dinosaurs,” Siraj said.

The model that the researchers published in the scientific journal “The Astrophysical Journal Letters” ( also has implications for the hypothetical Planet Nine, which Loeb and Siraj think “he’s not alone there”.

“The enigma concerns not only the Oort cloud, but also extreme trans-Neptunian objects (located beyond the orbit of the planet Neptune, the eighth planet from the Sun and the farthest in the solar system) such as the ‘eventual Planet Nine’,” says Loeb. said.

“It’s unclear where they came from, and our new model predicts that there should be more objects with a similar orbital orientation to Planet Nine,” the researchers note.

They explain that the Oort Cloud and the proposed location for Planet Nine are so far from the Sun that direct observation is a challenge for scientists.

Future observations from the Vera C. Rubin Observatory (VRO), located in Chile and which will start operating in 2022, could confirm or refute the existence of Planet Nine and its origins, according to Harvard researchers.

“If the Sun had an early companion that helped form the outer solar system, its current absence raises the question of where did it go? This ‘lost companion’ could have been removed long ago (by the gravitational influence of other stars) and now be found anywhere in the Milky Way.”

Ricardo Segura


#SCIENCE #lost #twin #sun

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