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
109
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] The passage is primarily concerned with
选项
A、describing an important technique
B、discussing a new method
C、investigating a controversial procedure
D、announcing a significant discovery
E、promoting a novel application
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3353776.html
相关试题推荐
Solve|4x-6|=10forx.-1Tosolvethisproblem,setuptwoequationsbecausex
A、Traditionalirrigationmethodstendtocomeatalowerexpensethanmoremoder
Adamswasso______thathisfriendsdidnotbotherto______him,becausethey
A、Thesheepwaschosenasanidealsubjectbecauseofitsgeneticdevelopment,n
A、isanevolutionaryadvantagebecauseitallowsthemalesandfemalesofthesp
Itisthemarkofaneducatedmindtorest______withthedegreeofprecisionw
Becausemanyoftheblacklistsinthecommunicationsandentertainmentindustrie
CarlJung’swell-documentedbreakwithSigmundFreudoccurredbecause
CarlJung’swell-documentedbreakwithSigmundFreudoccurredbecause
Modernbodiesareespecially______tocancer,nodoubtbecausethetechnologywhi
随机试题
Whenwillthenewpricetakeeffect?On______.[br]What’sthepurposeof
档案学者()于1901年提出的“高龄案卷应当受到尊重”为核心的档案鉴定思想
阶级斗争根源于()A.阶级在政治态度上的根本对立 B.阶级在思想观点上的根本对
下列关于工程量清单计价合同价款约定正确的有()。A.实行招标的工程合同价款应在中
沥青混合料所用粗集料是指粒径大于()mm的碎石、破碎砾石和矿渣等。A.4.75
土地利用总体规划的审批实行()制度。A:分级审批 B:统一审批 C:逐级上
旅游需求价格弹性系数|EP|>1时,一般来说将价格下降5%,将引致( )。A.
甲卷烟厂为增值税一般纳税人,主要生产销售A牌卷烟,2020年1月发生如下经营业务
下列各项公式中,错误的是()。A.安全边际率=1/经营杠杆系数 B.安全
某宾馆工程,由于业主急于按期开业迎客,于工程完工后在未进行竣工验收情况下就对外营
最新回复
(
0
)