For #PrinterSolstice prompt spectrum: my #linocut of trailblazing American #astronomer Annie Jump Cannon (1863 – 1941) with her stellar classification system which sorted stars based on spectral types, revealing their temperature from hot blue stars to cool red stars: O,B,A, F, G, K & M. Named after the university the Harvard Classification her tremendous contribution was less visible. 🧵1/n