V1298 Tau is a young (10-30 Myr), approximately solar-mass star (1.10 ± 0.05 M⊙ ) in the Taurus star-forming region2,4,5,6,7,8. Observations by NASA's Kepler space telescope in its extended K2 mission9 revealed transits of the star by four different planets, each larger than Neptune2,3. The V1298 Tau planets occupy a sparsely populated region of the observed exoplanet period versus radius plane. As a young system of large planets, it provides a crucial snapshot of planetary architecture