“2016年IOAA理论第6题-造父变星的脉动”的版本间的差异
（创建页面，内容为“==英文题目== '''(T6) Cepheid Pulsations''' The star 𝛽-Doradus is a Cepheid variable star with a pulsation period of 9.84 days. We make a simplifying assumptio…”） |
|||
| 第1行： | 第1行： | ||
| + | {{需要解答}} | ||
==英文题目== | ==英文题目== | ||
'''(T6) Cepheid Pulsations''' | '''(T6) Cepheid Pulsations''' | ||
2019年9月11日 (三) 17:45的版本
|
|
本题目目前没有解答。要不要你来试试！ |
英文题目
(T6) Cepheid Pulsations The star 𝛽-Doradus is a Cepheid variable star with a pulsation period of 9.84 days. We make a simplifying assumption that the star is brightest when it is most contracted (radius being 𝑅1 ) and it is faintest when it is most expanded (radius being 𝑅2 ). For simplicity, assume that the star maintains its spherical shape and behaves as a perfect black body at every instant during the entire cycle. The bolometric magnitude of the star varies from 3.46 to 4.08. From Doppler measurements, we know that during pulsation the stellar surface expands or contracts at an average radial speed of 12.8 km s −1 . Over the period of pulsation, the peak of thermal radiation (intrinsic) of the star varies from 531.0 nm to 649.1 nm.
(T6.1) Find the ratio of radii of the star in its most contracted and most expanded states (𝑅1/𝑅2 ).
(T6.2) Find the radii of the star (in metres) in its most contracted and most expanded states (𝑅1 and 𝑅2 ).
(T6.3) Calculate the flux of the star, 𝐹2 , when it is in its most expanded state.
(T6.4) Find the distance to the star, 𝐷star , in parsecs
