You could touch a brown dwarf


In the picture on the right you can see the size difference again. The sun is compared with the above-mentioned Gliese 229a and the brown dwarfs Teide 1 and Gliese 229b. To emphasize the small size of the brown dwarfs, Jupiter is also shown next to Gliese 229b. As you can see, they are both the same size. The diameter is deceptive, however: Gliese 229b has a mass 20 times that of Jupiter. The mass of the sun is about 1000 times that of Jupiter. The diameter of Jupiter is about 140,000 km, the diameter of the sun is 1.4 million km (about 10 times as large).

Brown dwarfs are often found in young star clusters, for example the Pleiades, where they are still new and bright. You can find them there by comparing the sighted objects with the main row scale. If you can find a cool object only in the infrared part of the spectrum, it could very well be a brown dwarf.

Statistics say: the lower the mass of a star type, the more often it occurs. This is an advantage when looking for brown dwarfs. The Pleiades are so popular in the search not only because this cluster is relatively young, but especially because it contains almost no dust that would dim the light and darken the objects.