<p>After looking at <a href="https://astronomy.stackexchange.com/questions/14336/are-there-any-galaxies-which-fell-out-of-sight-horizon-due-to-cosmic-expansion">this question</a>, I am wondering, how long does it take for a galaxy or other space object, to disappear from our view from the Milky Way due to the expansion of the universe? Assume GN-z11 is our target object here, or some other notable distant object.</p>
<p><strong>Edit:</strong> As @PM2Ring said in a comment, <em>&quot;No galaxy that is observable today ever disappears (but does become increasingly redshifted.&quot;</em> So when does a target galaxy get so redshifted that we cannot see it anymore?</p>

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2021-01-29T21:45:42.363Z
It depends on how you define "disappear". ;) From [this comment](https://astronomy.stackexchange.com/questions/14336/are-there-any-galaxies-which-fell-out-of-sight-horizon-due-to-cosmic-expansion#comment25450_14338) on that page: *No galaxy that is observable today ever disappears (but does become increasingly redshifted)*. Also see https://astronomy.stackexchange.com/a/19910/16685 which has a helpful diagram.
PM 2Ring
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2021-01-30T13:59:19.720Z
Pm 2 Ring do you mean that there is no object far enough and receding fast enough to cross an event horizon? I was thinking it is possible.  Perhaps I should study again the famous article on "expanding confusion"...
Alchimista
<galaxy><universe><distances><redshift><observable-universe>
How long does it take for a galaxy (or other object) to disappear behind the cosmic sight horizon?
WarpPrime
# How long does it take for a galaxy (or other object) to disappear behind the cosmic sight horizon?

(Asked by: username_0 on 2021-01-29)

After looking at [this question](https://astronomy.stackexchange.com/questions/14336/are-there-any-galaxies-which-fell-out-of-sight-horizon-due-to-cosmic-expansion), I am wondering, how long does it take for a galaxy or other space object, to disappear from our view from the Milky Way due to the expansion of the universe? Assume GN-z11 is our target object here, or some other notable distant object.

**Edit:** As @username_1 said in a comment, *"No galaxy that is observable today ever disappears (but does become increasingly redshifted."* So when does a target galaxy get so redshifted that we cannot see it anymore?

**Tags:** galaxy, universe, distances, redshift, observable-universe

> **Comments:**
> **username_1**: It depends on how you define "disappear". ;) From [this comment](https://astronomy.stackexchange.com/questions/14336/are-there-any-galaxies-which-fell-out-of-sight-horizon-due-to-cosmic-expansion#comment25450_14338) on that page: *No galaxy that is observable today ever disappears (but does become increasingly redshifted)*. Also see https://astronomy.stackexchange.com/a/19910/16685 which has a helpful diagram.  
> **username_2**: Pm 2 Ring do you mean that there is no object far enough and receding fast enough to cross an event horizon? I was thinking it is possible.  Perhaps I should study again the famous article on "expanding confusion"...  

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