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
44
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
Itdoespayyoutoberespectfultootherpeople.A、尊敬别人,确实对你有好处。B、尊敬别人,确实会付钱给你。
[audioFiles]2018m3x/audio_ezfj_ezflisteningd_201803_197[/audioFiles]Water
Jupiteristhe(big)______oneamongthenineplanets.biggest木星是九大行星中最大的。在比较级中,
人的因素对建设工程项目质量形成的影响是指直接履行建设工程项目质量职能的决策者、管
1978年12月18~22日,党的十一届三中全会在北京举行,( )在会上作了《
风管安装时,其支、吊架或托架不宜设置在()处。A.风口 B.风阀 C.风管法
带()的耦合电容器应无渗漏油,油色、油位正常,油位指示玻璃管清晰无碎裂。线路TV
将质量为m的物体在空气中竖直上抛,初速度为v0,若空气阻力与物体的速度v(t)(
甲与乙因买卖合同履行问题发生争议,根据事先约定申请仲裁。甲若想申请证据保全,应该
挖方的路基压实作业中,碾压应( )进行。A.自路中心向两边 B.自两边向路中心
最新回复
(
0
)