There is just solar system research as the term 'astronomer' has been so devalued by experimental theorists and their hapless RA/Dec cronies that they can't enjoy the new partitioning of direct/retrograde motions of the faster-moving and slower-moving planets as seen from a moving Earth in a Sun-centred system.
The direct/retrograde motions of the slower-moving planets as seen from a faster-moving Earth use a stationary field of background stars that represented the Ptolemaic framework of Copernicus, Kepler and Galileo-
https://apod.nasa.gov/apod/ap011220.html
That is the Earth overtaking Jupiter and Saturn causing them to fall behind in view hence their retrograde motion where they seem to move backwards when it is the faster moving Earth creating the spectacle.
The direct/retrograde motions of the faster-moving Venus and Mercury seen from a slower-moving Earth requires an entirely different framework made possible by a tracking satellite with the Earth around the Sun-
https://www.youtube.com/watch?v=w2uCtot1aDg
The satellite looks in towards the inner solar system and sees Venus and Mercury pass behind the Sun ( direct motion) and then between the slower-moving Earth and the central Sun ( retrograde motion).
The hapless people who follow Newton's attempt to create an alternative resolution for direct/retrograde motions by conjuring an absolute/relative space and motion into existence are lost souls in this matter-
"For to the Earth planetary motions appear sometimes direct, sometimes
stationary, nay, and sometimes retrograde. But from the Sun they are
always seen direct,..." Newton
Relativity, based on Newton's absolute/relative definitions above, is a nuisance contrivance when the real work is back with Copernicus and Kepler.
Maybe someday theorists will drop the pretence and research something useful instead of entertaining themselves at the expense of genuine solar system research.
Btw, none of the original astronomers got the direct/retrograde motions of Venus and Mercury right as they were chained to the Ptolemaic reference system