An article published in the journal “Astronomy & Astrophysics” describes a study of the brown dwarfs that should be present in the cosmic neighborhood. A team of astronomers from the Leibniz-Institut für Astrophysik Potsdam (AIP), Germany, re-analyzed data from observations and cataloging of the brown dwarfs less than six and a half parsecs from Earth and concluded that there should be more of them and maybe we haven’t found them yet.

Brown dwarfs are a class of objects on the border between the planet and the star. Their mass is significantly higher than that of Jupiter but much smaller than that of the Sun or even of a red dwarf star. Their mass is not enough to ignite the nuclear reactions typical of stars and it’s for this reason that brown dwarfs are considered failed stars.

Only in recent years, thanks to the detection of brown dwarfs, we’re really learning to understand these objects. Figuring out how many there really are in the various regions of the sky can help us understand the mechanisms of formation and movement of the stars in the Milky Way.

For this reason, Gabriel Bihain and Ralf-Dieter Scholz analyzed the distribution of the known brown dwarfs less than six parsec and a half (almost 21.2 light years) from Earth. The result is that they noticed a marked asymmetry that differs from the known distribution of the stars. Approximately half of the sky seems empty of brown dwarfs.

That’s an unexpected result, also because the distribution of stars in the same area is uniform. The researchers say it’s unlikely that things are really like that so, unless it’s an anomaly, the problem is due to an incomplete knowledge of brown dwarfs in the cosmic neighborhood.

The existence of brown dwarfs was theorized already in the ’60s but only at the end of the ’80s the first celestial body that had their features was identified. In the ’90s the study of these objects became more common with the discovery of other brown dwarfs. Today they’re divided into various spectral classes but astronomers are still discovering new information about them thanks to the identification of other brown dwarfs.

NASA’s WISE space telescope discovered many new brown dwarfs, a further indication that probably in the area where they’re missing they have yet to be identified. Their small size and their low emissions make it difficult to discover them but research continues to find the existing ones.