The idea is based on the fact that a macroscopic state of dark matter, with a mass or radius similar to that of a planet, would behave like a “dark exoplanet” when limited to a stellar system.
A group of researchers maintains that, if certain conditions are met, planets made entirely of dark matter could exist in different parts of the Universe, and that they could even be detected. Taking into account that its gravitational interaction force would be small but constant with the particles that make up conventional matter, a dark matter exoplanet may not be completely opaque, which would make the shape of its light curve distinguishable with respect to the from an ordinary exoplanet, according to scientists.
A team of scientists led by theoretical physicist Yang Bai, from the University of Wisconsin-Madison, in the United States, raises in a new study, recently published in arXiv, the possible existence of “dark planets”. These hypothetical planetary bodies, composed of 100% dark matter, could even be detected with current telescopes and observation methods, according to the group of American specialists.
The great mystery
Until now, science has discovered that planetary systems that support their dynamics in stars other than the Sun are made up of exoplanets of baryonic or conventional matter, as reflected by their physical conditions when they crossed in front of their host star and were identified by scientists. astronomers. This makes sense, considering that our own home in the Milky Way, the Solar System, is also made up of planetary bodies made of conventional matter. However, one of the great mysteries of astrophysics and cosmology remains, to this day, the enigmatic dark matter. It is a type of matter that is not dark energy, baryonic matter or neutrinos, and that makes up an important part of the cosmos. Since it does not interact with the electromagnetic field, it is impossible to observe it directly, but the gravitational effects that it produces on objects that we can observe allow us to deduce its existence.
The great mystery
Until now, science has discovered that planetary systems that support their dynamics in stars other than the Sun are made up of exoplanets of baryonic or conventional matter, as reflected by their physical conditions when they crossed in front of their host star and were identified by scientists. astronomers. This makes sense, considering that our own home in the Milky Way, the Solar System, is also made up of planetary bodies made of conventional matter.
However, one of the great mysteries of astrophysics and cosmology remains, to this day, the enigmatic dark matter. It is a type of matter that is not dark energy, baryonic matter or neutrinos, and that makes up an important part of the cosmos. Since it does not interact with the electromagnetic field, it is impossible to observe it directly, but the gravitational effects it produces on objects that we can observe allow us to deduce its existence.
In addition, it has been determined that the gravity in the Universe far exceeds the amount of baryonic matter present in the cosmos. Scientists have estimated that if we add the gravity exerted by all the objects and bodies that make up the Universe and that can be visualized, there is still an excess of gravity that does not come from structures made up of conventional matter. That force, still inexplicable until today, has been called dark matter.
Dark matter planets and the possibility of detecting them
According to a paper published in Science Alert, Bai and his colleagues believe there may be “macroscopic dark matter blobs,” called Macros, that could have masses on a planetary scale. It would be a macroscopic state of dark matter with a mass or radius similar to that of a planet: in this way, Macros with this magnitude would behave like a “dark exoplanet” if they are limited to a star system. This could happen even if the underlying physics of the object resembles something completely different from what has been known until today, the specialists in the study explain.
As if this were not enough, experts argue that these “dark planets” could also be detected through current methods and instruments. Since its force of gravitational interaction would be minimal but permanent with the particles that make up conventional matter, a dark matter exoplanet may not be totally opaque, resulting in the shape of its light curve (the change in reflected light over time). of time) differs, even slightly, from that produced by the other exoplanets.
So far, the theory only contemplates circular orbits, but many dark matter exoplanets could have elliptical orbits, especially if they have been captured by the gravity of a star. Consequently, the scientists conclude that the study must be enriched in the future with new perspectives, to advance the possibility of detecting dark matter exoplanets and confirm their existence.
Reference
Dark Exoplanets. Yang Bai, Sida Lu and Nicholas Orlofsky. ArXiv (2023). DOI: https://doi.org/10.48550/arXiv.2303.12129