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| https://exoplanets.nasa.gov/news/1450/scientists-improve-brown-dwarf-weather-forecasts/ |
https://science.slashdot.org/story/19/05/30/0257253/brown-dwarf-atmospheres-as-the-potentially-most-detectable-and-abundant-sites-for-life
Brown Dwarf Atmospheres As The Potentially Most Detectable And Abundant Sites For Life
RockDoctor writes:Yet another provocative paper emerges onto Arxiv from Harvard's Lingam and Loeb. Today they estimate the volume of space occupied by habitable zones (regions where liquid water is stable) in brown dwarf not-quite stars. They find that it could be orders of magnitude greater than the volume in the atmospheres of Earth-size planets. Brown dwarfs are masses of gas which are too small to sustain nuclear fusion (so, they're not stars), but can have a brief period of fusion of deuterium or lithium shortly after formation (so they're not planets; the boundary size is under debate). After this burst of energy, they slowly cool, for billions of years. This leads to a large volume of the star's outer body -- or atmosphere -- with potentially attractive temperature and pressure. If the brown dwarf is orbiting with a larger star, there may be enough light to allow photosynthesis. Supply of chemicals is uncertain, but not impossible.
While this paper is speculative, the prospects for detecting such life by spectroscopy are plausible with observational instruments being designed at the moment. Previous work on abiogenesis and the origin(s) of life has speculated that life could persist in the atmospheres of Venus and Jupiter, using comparable pressure-temperature arguments. In this respect, the proposal is more conventional.
TO EXPLORE MORE
https://en.wikipedia.org/wiki/Brown_dwarf
https://www.nasa.gov/feature/goddard/2017/nasa-funded-citizen-science-project-discovers-new-brown-dwarf/
http://www.astronomy.com/news/2016/08/when-does-a-small-star-become-a-brown-dwarf
https://phys.org/news/2017-05-brown-dwarf-planetary-mass.html
https://science.howstuffworks.com/brown-dwarf-isnt-failed-star-magnetic-powerhouse.htm
https://blog.backyardworlds.org/2017/02/24/brown-dwarf-the-object-you-should-start-to-love/
Brown Dwarf: The object you should start to love…
FROM -
http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/brown_dwarfs.html
Brown Dwarfs
| Brown dwarfs are objects which are too large to be called planets and too small to be stars. They have masses that range between twice the mass of Jupiter and the lower mass limit for nuclear reactions (0.08 times the mass of our sun). Brown dwarfs are thought to form in the same way that stars do - from a collapsing cloud of gas and dust. However, as the cloud collapses, it does not form an object which is dense enough at its core to trigger nuclear fusion. The conversion of hydrogen into helium by nuclear fusion is what fuels a star and causes it to shine. Brown dwarfs were only a theoretical concept until they were first discovered in 1995. It is now thought that there might be as many brown dwarfs as there are stars. |
| Brown dwarfs are very dim and cool compared with stars. The best hope for finding brown dwarfs is in using infrared telescopes, which can detect the heat from these objects even though they are too cool to radiate visible light. Many brown dwarfs have also been discovered embedded in large clouds of gas and dust. Since infrared radiation can penetrate through the dusty regions of space, brown dwarfs can be discovered by infrared telescopes, even deep within thick clouds. Recently, 2MASS(Two Micron All Sky Survey) data revealed the coolest known brown dwarf. To the left is an infrared image of the Trapezium star cluster in the Orion Nebula. This image was part of a survey done at the United Kingdom Infrared Telescope ( UKIRT) in which over 100 brown dwarf candidates were identified in the infrared. |
| The discovery of objects like brown dwarfs will also give astronomers a better idea about the fate of our universe. The motion of the stars and galaxies are influenced by material which has not yet been detected. Much of this invisible dark matter, which astronomers call "missing mass", could be made up of brown-dwarfs. Our universe is currently expanding, due to the Big Bang. If there is enough mass, it is thought that the expansion of the universe will eventually slow down and then the universe will start collapsing. This scenario could mean that the universe goes through an endless cycle of expansions and contractions, with a new Big Bang occurring every time the universe ends its collapse. If there is not enough mass for the universe to collapse, then it will expand forever. We will only know the fate of the universe when we can accurately estimate how much mass the universe has in it. The detection missing mass objects, such as brown dwarfs will likely be a key to answering this question. |
| Brown Dwarfs were only a theoretical concept when the Spitzer Space Telescope was first proposed. Since the mid-1990s, various infrared telescopes and surveys have identified a few hundred of these objects. Spitzer will devote much of its time to the discovery and characterization of brown dwarfs. It is expected that Spitzer will study thousands of these objects, including those only slightly larger than Jupiter. This will provide astronomers with enough data on brown dwarfs for good quality statistical studies. |
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- Bloggery committed by chris tower - 1905.29 - 10:10
- Days ago = 1425 days ago
- New note - On 1807.06, I ceased daily transmission of my Hey Mom feature after three years of daily conversations. I plan to continue Hey Mom posts at least twice per week but will continue to post the days since ("Days Ago") count on my blog each day. The blog entry numbering in the title has changed to reflect total Sense of Doubt posts since I began the blog on 0705.04, which include Hey Mom posts, Daily Bowie posts, and Sense of Doubt posts. Hey Mom posts will still be numbered sequentially. New Hey Mom posts will use the same format as all the other Hey Mom posts; all other posts will feature this format seen here.
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