The star delta Cephei has a declination of about +58.5 degrees.Which observer will see it above their horizon for the longest fraction of one night?
A)an observer in Valdivia, Chile, at a latitude of 39° S
B)an observer in Windhoek, Namibia, at a latitude of 22.5° S
C)an observer in Zacatecas, Mexico, at a latitude of 22.5° N
D)an observer in Edmonton, Canada, at a latitude of 53.5° N

Question

Quizplus · Accepted Answer

The star delta Cephei has a declination of +58.5 degrees, which means it will always be above the horizon for observers at latitudes higher than 58.5 degrees south and visible for longer times as the latitude increases further towards the North Pole. Among the given options, the latitudes of Edmonton, Canada, and Valdivia, Chile, are higher than +58.5 degrees, but Valdivia is located in the southern hemisphere, where delta Cephei will be lower in the sky and visible for a shorter time than in the northern hemisphere. On the other hand, Windhoek and Zacatecas are at lower latitudes than delta Cephei's declination, so the star will not be visible to them at all. Therefore, an observer in Edmonton, Canada, at a latitude of 53.5° N will see delta Cephei above their horizon for the longest fraction of one night.

The Star Delta Cephei Has a Declination of About +58