USAAAO — 2024 First Round

Ben Chen is an alien living on a system identical to earth, except his planet’s obliquity is 0°. Located at latitude 42.20°, he wants to observe M52. Due to the open cluster being so dim, Ben needs perfect conditions to observe M52. Due to atmospheric effects, M52 can only be observed above an altitude of 30°. Additionally, it must be during astronomical twilight (when the Sun is more than 18° below the horizon). Of the following dates, which is the earliest after the vernal equinox that Ben can observe the cluster? The coordinates of M52 are approximately α = 0h and δ = 60°.