There isn't a single "farthest known star" because we are constantly discovering new, more distant objects. However, as of December 2022, Earendel is the most distant star we've observed directly.

It's important to note that:

* Earendel's distance is estimated at approximately 12.9 billion light-years away. This means we see it as it was 12.9 billion years ago, just 900 million years after the Big Bang.

* Earendel is exceptionally bright and magnified by a massive galaxy cluster acting as a gravitational lens. This allowed us to see it at such a great distance.

As technology advances, we'll likely continue to find even more distant stars. So, while Earendel holds the title currently, it's only a matter of time until another star takes its place as the farthest known.