Astronomers identify purest, most massive brown dwarf



In the article, “Astronomers identify purest, most massive brown dwarf,” the author explains how astronomers have recently identified a record breaking brown dwarf, which  according to the author is a “a star too small for nuclear fusion”. Throughout this whole article the author talks about characteristics and information about the brown dwarf that was discovered. First, the author begins to talk all about these brown dwarfs. He first starts to talk about how they are middle sized . The author  states, “they are intermediate between planets and fully-fledged stars. Their mass is too small for full nuclear fusion of hydrogen to helium (with a consequent release of energy) to take place, but they are usually significantly more massive than planets.” which proves they are intermediate sized. . Than , this article begins to talk about the size and pureness of this brown dwarf. The author explains how this brown dwarf is “purer than the sun ” and “90 times bigger than Jupiter”. Lastly this article talks bout what this brown dwarf was classified as. The author exactly states “SDSS J0104+1535 has been classified as an L type ultra-subdwarf using its optical and near-infrared spectrum, measured using the European Southern Observatory’s “Very Large Telescope” (VLT). This classification was based on a scheme very recently established by Dr Zhang.”

Conceptional Objective 12 was to explain how astronomers use the Hertzsprung-Russell diagram to study properties of stars. An H-R diagram plots stars according to their surface temperatures (or spectral types) and luminosities. The horizontal axis of the H-R diagram represents temperature which correlates with spectral type. The vertical axis represents luminosity which correlates with absolute magnitude. Stars spend most of their lives fusing hydrogen into helium in their cores, and stars in this stage of life are found on the main sequence. The power point slides in class taught us that most stars are on the main sequence and their size is related to temperature and luminosity. The more massive main sequence stars are more luminous, larger, and hotter. There are also giants and white dwarf stars which are not on the main sequence. Giants are bright and large to the upper right of the main sequence. White dwarfs are hot and small, located to the lower left of the main sequence. This article discusses brown dwarfs which are neither planets nor stars. However, the textbook states that the sequence of spectral types has recently been extended further than type M to include spectral types L and T, representing starlike objects, such as brown dwarfs, which are even cooler than stars of spectral type M (p. 314). According to this information, if brown dwarfs were to be added to the H-R diagram and it were extended to spectral types L and T, they would likely be to the lower right portion below the lowest main sequence stars because of their cool temperature and small size.

I personally really enjoyed this article because a “brown dwarf” is something that i was completely unfamiliar with before reading this article. Therefore i was interested in learning about it especially the unique facts like it is 90 times bigger than Jupiter and purer than the sun. I was also very into how they classified this brown dwarf , which was explained in the article . I also liked this article because even though brown dwarfs are not technically stars I felt that they still relate to this objective because they have many similarities and can be applied to the H-R diagram.


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