Geocentric altitude/az of the sun and moon.

[hidp123]

Normally, alt & az are topocentric. However, how can I get geocentric alt & az. The altitude at least, if not azimuth.

I ask mainly due to the following:

[brandon-rhodes]

The center of the Earth, the geocenter, does not have a horizon — so there would be no way to compute an angular altitude above that horizon, I don't think?

[hidp123]

Agree, it is definitely a strange one.

So far looking at other libraries I have found Swiss Ephemeris has this option, and cosinekitty at astronomy-engine managed to put together something for me in this regard using his library.
Here (Swiss Ephemeris) and here is my discussion with cosinekitty in regards to this.
I was hoping it can also be calculated via skyfield due to skyfield's high level of accuracy.

@brandon-rhodes