Whakakiia te rerenga e whai ake nei: I te wehenga atu o Pickering i te tau 1921, ka riro te Kaiwhakahaere o HCO ki a Harlow Shapley (he kaiuru nui i te "
Te Kōrero Nui" o te 1920). I rongonui tenei waa o te tirohanga ma te mahi a Cecelia Payne-Gaposchkin, ko ia te wahine tuatahi i whiwhi tohu PhD i roto i te whetu mai i te Radcliffe College (he hikoi poto mai i te Maatauranga). Ko te tuhinga a Payne-Gapochkin i te tau 1925 i kii ko nga whetu he mea hanga i te hauwai me te helium, he whakaaro i whakaarohia he maamaa i taua wa. I waenga i te wa o Shapley me te hanganga o te CfA, ko te kaitirotiro i arahina e Donald H. Menzel, katahi ka Leo Goldberg, i mau tonu nga kaupapa e mohiotia whanuitia ana i roto i te solar me te stellar astrophysics. I whai wāhi nui a Menzel ki te whakatenatena i te Smithsonian Astrophysical Observatory ki te neke ki Cambridge me te mahi tahi me te HCO.