Question

Question 10 (1 point) Delta Cephei is a cepheid variable star with a period of variability of about 5.4 days. Eta Aquilae is another cephei variable star with a period of about 7.2 days. Delta Cephei appears to be nearly the same brightness as Eta Aquilae to observers in Winnipeg. Which of the following is true? Delta Cephei is more luminous than Eta Aquilae and is further away Delta Cephei is more luminous than Eta Aquilae and is the same distance Delta Cephei is more luminous than Eta Aquilae and is closer to Earth Delta Cephei is less luminous than Eta Aquilae and is further away Delta Cephei is less luminous than Eta Aquilae and is the same distance Delta Cephei is less luminous than Eta Aquilae and is closer to Earth

Answer 1

period of variability of delta cepheid (To) = 5.4 days. period – – – – Eta Aquilae (TE)= 7.2 days fer cepheid variable stars:- as I luminosity (sort) Time (units) fosklows this kind of behavious So, so a crude approximation :- La period of variability. lemminosity luminosity, 12 af delta hence as we u Te> to 4 Eta Agulan) Cepher Eta Aquilae is more luminous than de ta cepheid. less luminous than Eta or Delta cepheid is Aquilae seeme more bright. also as near they start objects came As in both persons winnipeg see stars as same bright than Eta should be closer to earth so, Delta Cephed Aquilar to be seem same geight. luminous than Eta Aquilae cephei is less "Delta cephei " and is closer to Earth." Last option is correct.