[HN Gopher] Astronomers just discovered the farthest object in t...
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       Astronomers just discovered the farthest object in the known
       universe
        
       Author : wglb
       Score  : 44 points
       Date   : 2022-04-08 18:19 UTC (4 hours ago)
        
 (HTM) web link (www.livescience.com)
 (TXT) w3m dump (www.livescience.com)
        
       | SkyMarshal wrote:
       | Key sections:
       | 
       |  _" The researchers discovered HD1 in data collected over 1,200
       | hours of observation time using the Subaru Telescope, the VISTA
       | Telescope, the U.K. Infrared Telescope and the Spitzer Space
       | Telescope. They were particularly looking at redshift, a
       | phenomenon in which light waves stretch out or become redder as
       | an object moves away from the observer. In this case, the
       | redshift suggested HD1 was extremely distant.
       | 
       | The researchers found that the red wavelengths were the
       | equivalent to a galaxy located 13.5 billion light-years away.
       | 
       | HD1 also seems to be growing at a feverish rate -- about 100
       | stars each year, or at least 10 times the rate predicted for
       | starburst galaxies that are known to produce stars at an
       | extraordinarily high pace.
       | 
       | These stars were also more massive, brighter (in ultraviolet
       | wavelengths) and hotter than younger stars, the researchers
       | found.
       | 
       | As such, HD1 could be home to the universe's very first stars,
       | called Population III stars; if that identity is verified, this
       | would be the first observation of this type of star, the
       | researchers said. There's also the possibility that HD1 is a
       | supermassive black hole with a mass of about 100 million times
       | that of the sun."_
       | 
       | Also a paper on it: https://arxiv.org/abs/2201.00823
        
         | 8bitsrule wrote:
         | Paper sez: z ~ 13
        
         | thanatos519 wrote:
         | I can't wait for JWST to look over there!
        
       | karmakaze wrote:
       | Would it be more accurate to say 'oldest' since it's not there as
       | we're seeing it now?
       | 
       | I suppose it's all the same in space-time. But what we study
       | about it is more in relation to the time of the light rather than
       | the place, so 'oldest' has a more relevant connotation.
        
         | rich_sasha wrote:
         | We have also seen very old objects closer by.
         | 
         | The Methuselah star is estimated to be 13.7 billion years, in
         | fact by some estimates older than the universe (which is
         | clearly somewhat problematic).
         | 
         | It is a mere 190 light years away.
        
       | onlyrealcuzzo wrote:
       | Is there a physical limit to the resolution we can get from such
       | absurdly large distances? And if so - is there an equation?
        
       | lil_dispaches wrote:
       | The Big Bang is the diffraction of logic around the perimeter of
       | the lens on the universe we call Quantum Physics.
        
         | marginalia_nu wrote:
         | That's not even wrong.
        
         | ericmay wrote:
         | Could you expand on what you mean by this?
        
           | simonh wrote:
           | No, sorry, please don't.
        
       | Archelaos wrote:
       | Layperson's question: The article talks about "a possible galaxy
       | that exists some 13.5 billion light-years from Earth". But isn't
       | that just the light traveling distance, and the object should
       | actually be much further away due to the expansion of the
       | universe?
        
         | spindle wrote:
         | Speaking as someone who used to teach introductory cosmology at
         | a good university ... your question is not a layperson's
         | question! (That's a compliment, BTW.)
        
         | sph wrote:
         | To add my dumb question: since the universe expands faster than
         | light, how is this considered a very far object and not just
         | that we're looking at something in the past? Is this confusion
         | of mine between distance and time what physicists mean by
         | space-time?
        
         | simonh wrote:
         | Well spotted yes, by now that object will be about 45 bn ly
         | away. The light reaching us from it has only traversed 13.5 bn
         | ly though.
        
           | cygx wrote:
           | What are you basing the 45 bn ly on? A redshift of z~13
           | should correspond to a comoving distance of about 33 bn ly,
           | whereas 45 bn ly would correspond to z~600.
        
           | sdeframond wrote:
           | Define "now"
           | 
           | https://en.m.wikipedia.org/wiki/Relativity_of_simultaneity
        
             | simonh wrote:
             | While that's a problem in theory, to moderate accuracy it's
             | not a practical issue. Most objects in the universe are
             | roughly at rest relative to the cosmic background radiation
             | (in other words they don't see it as Doppler shifted in any
             | particular direction), so we can use that as a common frame
             | of reference. When we're talking about ballpark integer
             | billions of years, or even to a few decimal places, that's
             | easily good enough.
        
         | layer8 wrote:
         | "Light-years" literally _is_ light-traveling distance, though.
         | :)
        
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       (page generated 2022-04-08 23:01 UTC)