Brown Dwarfs: Failed Stars

In the article, Brown Dwarfs: Failed Stars Resembling Planets on, author Nola Taylor Redd explains the different formation of a brown dwarfs from other stars in the universe. Not every gas cloud in the universe collapses into the perfect star. Sometimes stars just don’t quite make it as a star. The life of a brown dwarf starts on the main sequence, just like many others. For most stars, gravity pulls inwards and hydrogen fusion starts in the core. Brown dwarfs never reach this stage. Before the temperatures in the star’s core are hot enough for fusion, the material compacted together inside becomes in a stable state and it becomes a brown dwarf. Some astronomers refer to them as “failed stars.” Brown dwarfs can sometimes be confused with planets. Like planets, brown dwarfs have atmospheres, clouds and even storms. But like stars, brown dwarfs can host their own planets. To be able to tell the difference between a planet and a dwarf star is to see if it is giving off it’s own light or reflecting it. Since they emit such small amounts of energy and give off very little light, brown dwarfs are very tricky to locate.

Brown dwarfs are seen easier in the infrared, but can still be hard to detect. The image above shows a visible light image of a brown dwarf right in the center of the cross hairs. This just shows how faint they appear to be to the naked eye.

This article relates to class and our conceptual objective, “I can describe how stars form and produce energy in their cores by nuclear fusion.” This article discussed what happens to the stars that don’t go through nuclear fusion. We have learned from our notes that as stars age in their life, the fusion conducting at their cores gradually grows. In our lecture tutorials workbook, we worked on the Star Formation and Lifetimes section. From this section, it explains that the life of star begins from a disturbance to a cloud of gas and dust, possibly a shock wave from a supernova. The inward collapse of material causes the center of the protostar, a star formed from the collapse of gas and dust, to become very hot and dense where fusion begins. For brown dwarfs, the temperatures never reach what they need to be for fusion to begin.

Reading this article, has gotten me interested in what other kinds of stars there are. I know about the red giants and dwarfs and those along the main sequence, but the universe is infinite and we have only studied a fraction of it. I’m looking forward to reading the new discoveries in the universe. Overall, I enjoyed this article.


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