How long can someone standing at the equator shortly after sunset observe the same constellation? 12 hours?

maximum ( about) the turning earth means they all appear to go to set in the west

so one that is overhead, not on the eastern horizon would "set" about midnightHow long can someone standing at the equator shortly after sunset observe the same constellation? 12 hours?It depends upon where the constellation is at sunset time.



The maximum it is (presuming you neglect its angular width) ever visible for is not 12 hours...but 11 hours and 58 minutes (one half of a sidereal day)...and this assumes that you have perfect nighttime for the full period of observation...which is nearly true because day and night are always officially 12 hours each on the equator.How long can someone standing at the equator shortly after sunset observe the same constellation? 12 hours?Well, the maximum possible would be the length of the night - around the spring or autumnal equinox, you might have darkness for slightly over 12 hours, and thus, you would be able to view some constellations for that time.