I think that Atheists are not wont to be rife in the study of Astrology considering the vast number of metaphysical principles that permeate the study. Astrologers are given first hand to witness what they regard as something transcendent and spiritual in operation in our lives. In this they discern something which refutes the callow Atheists and exposes their fundamental inexperience, such as it is.
Conversely, though, it is conceivable that many Atheists have been drawn to the study of Astrology for reasons their own. As a result of their incredulous frame of reference, they are more likely, I think, to want to winnow away from the practice the age-old metaphysical precepts underpinning it in order to make it more permissible. That is to say, to make it more acceptable to them and to make themselves more acceptable for bothering about it in the first place. Probably they would elevate it to the rank of science and fact before they could deign to study it with seriousness and intent.
If you are looking for Atheistic-Astrology exemplars, then I can offer you none. But I can affirm that I have met an unreckonable number of astrologers from diverse backgrounds and more diverse systems of belief and all of them without exception have been metaphysically inclusive. But, to be sure, I do not think that Atheism and Astrology are mutually exclusive. Hopefully this has been of some worth for you.
Perhaps I should also add that I approve of neither of these two systems. Often the people one observes on this site and elsewhere who partake of some spiritual dogma are enough to beggar belief themselves; it simply doesn't do to have one's head in the clouds and to dwell on terribly abstract, implausible concepts of cloudy this and that. There is a real world in which we dwell, and I can assure you that it is very costly to neglect that fact. It is callous and trying but at least it is.
Moreover, one should neither be loathe to investigate the matter of God. It is my opinion that every individual is responsible for probing this important concept on his own. Religion is mere herd instinct and cannot allow for a very fulfilling sense of the transcendent, at least not if you are possessed of an even slightly enquiring intellect. That said, I have had sufficient experience in this regard as a direct result of my belief that each individual must explore this for himself. It surely merits the attempt. What conclusion you draw is your own business, but whatever it may be at least it is your own.