Ok - here we go -
A website sais the image we see of it is 8.95 billion light years old but its actual distance is 13.37 light years. So we see it where it was 9 billion years ago even though in reality its much farther.
That said - then is ANY quasar seen at its true distance or are we just looking at some much closer location? The Ursa Major one is about 13 billion light years if I recall but if we are to move it to where its currently at it can't possibly as great a difference as the Draco quasar.
Here's the link:
http://astronutcase.... Q1634 706.html
According to Hubble's law, the universe has expanded since the quasar's light was emitted, and a redshift is observed. Since light doesn't interact with itself, light waves expand as they travel through space.
What is redshift? It's the observed wavelength subtracted by the emitted wavelength, all divided by the observed wavelength. When you have a redshift value of 0, that's right here. When you have a redshift value of 1, that means the observed wavelength is twice as large as it was when it was emitted. For a redshift of 2, three times as large...etc.
Look back time:
- Is the numbers of years the light has been traveling to get to us
- Is NOT the distance to the quasar now (light years)
- Is NOT the distance to the quasar at time of emission (light years)
We have ways to calculate all three of these, but the last two are not as straightforward as the first.