首页
登录
职称英语
Because of its precision, the Cepheid-variable method of correlating
Because of its precision, the Cepheid-variable method of correlating
游客
2024-01-11
27
管理
问题
Because of its precision, the Cepheid-variable method of correlating the
luminosity of Cepheid stars with those of known types of ordinary stars is one of
the most important tools that astronomers have for ascertaining distances to
Line proximate galaxies. Fortunately, Cepheids are luminous enough to be observed
(5) in other galaxies, not just in our own, such that scientists have established a
benchmark for their true brightness. One first observes a Cepheid, notes the
time span for its luminance to vary, and plots that information on an already
established graph to derive its intrinsic luminosity. Comparing intrinsic
luminosity with apparent brightness allows one to calculate the star’s distance
(10) as long as the period-luminosity relation for the star in question is first corrected
for gravitational interference, parallax, and experimental error. Data gathered
by this process would suggest that the universe is expanding, but the method is
less reliable in the nether reaches of the universe, where the crucial evidence
for cosmic expansion would likely be spotted. [br] According to the passage, in the Cepheid variable method all of the following have a significant role in the calculation of the distance of a galaxy EXCEPT
选项
A、The intrinsic luminosity of a Cepheid
B、The comparative luminosity of ordinary stars
C、The observed brightness of the Cepheid
D、The data suggesting the expansion of the universe
E、The correction of the period-luminosity relation for the star being observed
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3353777.html
相关试题推荐
15is60%ofwhatnumber?25Usethedecimalequivalentof60%.Because60%ofsom
A、lesspraiseworthybecauseoftheabsenceofnewlisteningstrategiesthatallo
A、Traditionalirrigationmethodstendtocomeatalowerexpensethanmoremoder
CarlJung’swell-documentedbreakwithSigmundFreudoccurredbecause
A、isanevolutionaryadvantagebecauseitallowsthemalesandfemalesofthesp
Becausemanyoftheblacklistsinthecommunicationsandentertainmentindustrie
Mistierbecametheagency’s______,andhecontinuedassuchnotbecauseofhisl
CarlJung’swell-documentedbreakwithSigmundFreudoccurredbecause
CarlJung’swell-documentedbreakwithSigmundFreudoccurredbecause
Modernbodiesareespecially______tocancer,nodoubtbecausethetechnologywhi
随机试题
Afterseeingwhatdisasterhehadbroughttohisfamily,he______ofintemperat
[originaltext]W:Morning,thisisTGC.M:Goodmorning.WalterBarryhere,call
26岁,停经45天,阴道不规则出血4天,血HCG66μg/ml,结合超声图像,最
个人业绩考核关注的是()。A.绩效计划 B.绩效指标设定 C.绩效执行 D
公共建筑用气设备不官设置在地下室、半地下室内。当必须设置在地下室、半地下室内时,
A.心尖部听诊音调低,强度响,历时长 B.心底部听诊音调高,强度弱,历时短
中药的五味是指()A.酸、苦、甘、辛、麻 B.酸、甜、苦、辣、咸 C.
男性,45岁,低热咳嗽左侧胸痛2周,夜间偶有盗汗,胸片和B超提示左侧大量胸腔积液
Howcanhighschoolstudentsearncredit
下列生产控制方式中,具有反馈控制特点的是()。A.事前控制方式 B.事中控制
最新回复
(
0
)