In size, that is. But it's far dimmer than we'd expect a 13 Gly object to be. Space has been stretching all the time its image traveled, dramatically redshifting and weakening the light. It now exhibits the ultra-faintness of a galaxy at the impossible distance of 263 Gly.
Let's put all this together. It's the oldest galaxy image we've ever seen, which also makes it the youngest. It looks way too big for its distance, but also way too faint. Could things get any weirder?
You bet. Science articles say it's 13 Gly from here because distance is often ex-pressed that way. But that's merely how long its light took to reach us. During all that time, A1689-zD1 has been madly receding. This galaxy is now actually 30 Gly away. To get the true figures for these kinds of questions, use the calculator cosmologist Ned Wright of UCLA posts. Punch in a light-distance, and it'll give you the rest: http://www.astro.ucla.edu/~wright/DlttCalc.html
Now consider cosmic boundaries. The first stars or protogalaxies may have formed as early as 100 million years after the Big Bang; it's still debated. If so, they'll display angular sizes as if they're just 1.2 Gly away. But their brightnesses would indicate an inconceivable distance of 1.2 trillion
light-years — utterly undetectable. Their actual distance today would be 38 Gly. These parameters roughly mark the edges of the observable universe.
But objects do not end there. Most galaxies were never positioned for their light to be able to arrive here at all. Astronomers such as Wright believe at least 98.4 percent of the universe lies "over the horizon" in a zone that can never be observed. This can be a frustrating limitation. For example, something massive is disrupting the universe's smooth expansion in our region of space. Some sort of "great attractor" lies in the direction of Centaurus. Many astronomers think it's located outside our observable reality. It tugs on our visible universe from a place beyond.
That "place beyond" constitutes nearly all of the cosmos. And where does that
end? No one's sure, but it's likely the universe is, was, and always will be infinite in extent. If this is true, everything we can ever see represents 0 percent
of the total galactic inventory.