caption death_date death_place birth_place nationality field work_institutions birth_date known_for prizes image article_title name
hendrik c. van de hulst in 1977 31 july 2000 leiden , the netherlands utrecht , the netherlands dutch astronomy university of leiden 19 november 1918 21 cm hyperfine line henry karl schwarzschild medal draper medal eddington medal rumford medal bruce medal hendrik c. van de hulst 1977.jpg hendrik c. van de hulst
 hendrik c. van de hulst
hendrik c. van de hulst

hendrik christoffel `` henk '' van de hulst -lrb- 19 november 1918 -- 31 july 2000 -rrb- was a dutch astronomer and mathematician .
in 1944 , while a student in utrecht , he predicted the existence of the 21 cm hyperfine line of neutral interstellar hydrogen .
after this line was discovered , he participated , with jan oort and c.a. muller , in the effort to use radio astronomy to map out the neutral hydrogen in our galaxy , which first revealed its spiral structure .
he spent most of his career at the university of leiden , retiring in 1984 .
he published widely in astronomy , and dealt with the solar corona , and interstellar clouds .
after 1960 he was a leader in international space research projects .
in 1956 he became member of the royal netherlands academy of arts and sciences .
