Due to the finite speed of light and the expansion of the universe - with changing expansion rate - describing large scale distances in the universe is somewhat tricky. There are several different distances measures like proper distance and comoving distance. [1] I am totally not an expert on this but it is not necessarily contradictory that the observable universe is 93 billion light years across and that a star 9 billion light years away is halfway across the universe, those two statements may just use different ways of attaching a number to cosmological distances. The universe is only 13.8 billion years old and therefore no light could have reached us from more than 13.8 billion light-years away if the universe were not expanding.

[1] https://en.wikipedia.org/wiki/Distance_measures_(cosmology)

> Yet the "farthest star" article says the farthest star is only 9 billion light years away

I think you completely misread the article. This is the farthest star we've been able to observe directly at its normal luminescence, as in, not a supernova. Granted, it is due to gravitational lensing.

The article never says this is the farthest star that exists, simply the farthest (by far) that we've been able to directly observe.

What are the farthest stars we've been able to detect?

The farthest directly observed objects are galaxies and quasars, to about 13 billion light years from us. We have indirect evidence of individual stars that far out, but prior to this discovery the farthest directly observed star[1] (SDSS J1229+1122) was 55 million light years away, so this is quite a leap.

[1] http://www.skyandtelescope.com/astronomy-news/the-most-dista...

The news is that we can pick out a single star at that distance, due to a quirk of gravitational lensing. Normally we could only notice an entire galaxy.

There's also the metric expansion of space to consider:

https://en.wikipedia.org/wiki/Metric_expansion_of_space

"galaxies that are more than the Hubble radius, approximately 4.5 gigaparsecs or 14.7 billion light-years, away from us have a recession speed that is faster than the speed of light. Visibility of these objects depends on the exact expansion history of the universe. Light that is emitted today from galaxies beyond the cosmological event horizon, about 5 gigaparsecs or 16 billion light-years, will never reach us, although we can still see the light that these galaxies emitted in the past."

So we may be able to see light from objects that are further away today (if they still exist) but when they emitted the light they were closer than that.

You should read about the difference between comoving distance and proper distance.