Advanced Member
Posted 31 January 2018 - 05:00 AM
The forth closest star (7.27 light years) to the Sun, called WISE 0855-0714 is a brown dwarf star with a temperature of between -48C and -13C making it the coldest known star. I never knew stars could ‘burn’ so cold and it made me wonder if we could learn anything from this to help us develop a cold fusion power plant. Anyone have any thoughts on this?
Ref: https://en.wikipedia.../WISE_0855−0714
Creating
Posted 31 January 2018 - 10:46 AM
The forth closest star (7.27 light years) to the Sun, called WISE 0855-0714 is a brown dwarf star with a temperature of between -48C and -13C making it the coldest known star. I never knew stars could ‘burn’ so cold and it made me wonder if we could learn anything from this to help us develop a cold fusion power plant. Anyone have any thoughts on this?
Yeah. It's cobblers. 
There is no suggestion that fusion is going on in this object.
Edited by exchemist, 31 January 2018 - 10:54 AM.
Advanced Member
Posted 31 January 2018 - 03:48 PM
Yeah. It's cobblers.
There is no suggestion that fusion is going on in this object.
Oops, I see what you mean. I thought a star was a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions. In fact, as you point out, the brown dwarf star produces heat and light; but not by nuclear fusion, (because it doesn't have enough mass for the crush of gravity to ignite nuclear fusion at its core). So I’m revising my definition of a star to ‘a natural luminous body visible in the sky especially at night’. I’m not quite sure of the exact chemical reactions causing the heat and light but at least understand it’s not due to nuclear fusion. Thanks for pointing out the error.
Ref: https://news.nationa...-space-science/
Creating
Posted 01 February 2018 - 03:47 PM
Oops, I see what you mean. I thought a star was a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions. In fact, as you point out, the brown dwarf star produces heat and light; but not by nuclear fusion, (because it doesn't have enough mass for the crush of gravity to ignite nuclear fusion at its core). So I’m revising my definition of a star to ‘a natural luminous body visible in the sky especially at night’. I’m not quite sure of the exact chemical reactions causing the heat and light but at least understand it’s not due to nuclear fusion. Thanks for pointing out the error.
From what I read, the object in this case has a temperature so low that it is only emitting a bit of IR and microwave radiation, as expected for a body at that temperature. There are no stellar processes going on at all. It has ceased to be a star in any useful sense of the term. It is not producing any light, so far as I can see.
It may technically be a "brown dwarf" in terms of stellar evolution, but this example is black as the ace of spades.
Advanced Member
Posted 01 February 2018 - 05:11 PM
From what I read, the object in this case has a temperature so low that it is only emitting a bit of IR and microwave radiation, as expected for a body at that temperature. There are no stellar processes going on at all. It has ceased to be a star in any useful sense of the term. It is not producing any light, so far as I can see.
It may technically be a "brown dwarf" in terms of stellar evolution, but this example is black as the ace of spades.
Thanks for the feedback. The wiki ref. on my first post showed what looked like a bright star parallax tracking in front of the background stars. Turns out this was an animation of infrared light data and the brown dwarf 'star' cannot be seen in visible light. The reference below from NASA makes it clearer.
https://www.nasa.gov...-dwarf-20140425
