首页
登录
职称英语
The recently announced discovery of the first known planet orbiting a pulsar
The recently announced discovery of the first known planet orbiting a pulsar
游客
2024-01-10
40
管理
问题
The recently announced discovery of the first known planet orbiting a pulsar (the ultradense, pulsating remnant off the supernova explosion of a star) turned out to be based on faulty data. Had this discovery been confirmed, theorists would have had difficulty accounting for the existence of such a planet. The supernova would certainly have destroyed any preexisting planets. This particular pulsar is relatively young, allowing little time for a new planet to have coalesced, and it rotates relatively slowly, implying that it has not interacted with any nearby star since the supernova.
But newer evidence of a different pulsar with planets is more promising. This is a rapidly spurring “millisecond pulsar" thought to be a much older object that has pulled gaseous material from a stellar neighbor, causing its rotational speed to increase. Leftover, unconsumed gas around such a pulsar could, in theory, coalesce into planets. Or the pulsar’s radiation might have vaporized a companion star, providing new material for planetary formation. [br] Which of the following can be inferred regarding the pulsar discussed in the first paragraph?
选项
A、Theorists initially doubted its existence.
B、If its existence had been confirmed, astronomers would have turned their attention to the pulsar discussed in the second paragraph.
C、If the supernovas explosions that created it had been more powerful the resulting radiation would have preceded the subsequent formation of a planet.
D、If it had interacted with a nearby star since the supernova explosion, it would rotate faster than it does.
E、Astronomers’ interest in it ultimately led to a new theory of planetary formation.
答案
D
解析
根据第一段第四句的it rotates relatively slowly,implying that it has not interacted with any nearby star since the supernova可以推测出,如果脉冲星和周围恒星发生相互作用,就会转得更快。A项脉冲星的存在是客观事实,没人质疑这一点,A项质疑的是脉冲星附近的行星。B项文中未提及。C项根据第二段,脉冲星的辐射会促使行星的形成,而非超新星的辐射。E项行星形成的理论和天文学家的兴趣无关。
转载请注明原文地址:https://tihaiku.com/zcyy/3349559.html
相关试题推荐
Althoughthediscoveryofantibioticsledtogreatadvancesinclinicalpractice
Intheearlytwentiethcentury,thediscoveryofradium(i)____thepopularimag
Theimpactofarecentlypublishedcollectionofessays,writtenduringandabou
Withinthenextdecade,sophisticatedtelescopesnoworbitingtheEarthwilldet
ItispuzzlingtoobservethatJones’snovelhasrecentlybeencriticizedforit
Untilquiterecentlyresearchondiabeteshad,asakindofholdingaction,atte
Astronomerswhostudyplanetformationoncebelievedthatcomets—becausethe
Astronomerswhostudyplanetformationoncebelievedthatcomets—becausethe
Somehistorianshaverecentlychallengedthe“partyperiodparadigm,”thevi
Somehistorianshaverecentlychallengedthe“partyperiodparadigm,”thevi
随机试题
WearablegadgetslikesmartwatchesandGoogleGlasscanseemlikeafadtha
[originaltext]Hollywoodproducesmanydifferentkindsoffilms,includingm
集体土地所有权首次登记的申请人可以是( )。A.村集体经济组织 B.村民委员
A.桑寄生科B.三白草科C.蔷薇科D.唇形科E.豆科仙鹤草来源于
某小学少先队围绕“学雷锋”主题开展一系列少先队活动,体现了( )是少先队活动的
商业银行个人理财业务面临的主要风险有( )。A.法律风险 B.流动性风险
汇率政策中最基础、最核心的部分是()。A.促进国际收支平衡 B.确定
B正确答案是B。 提示:逐项排除。 选项A:是模拟信号,而x(t)和u(t)是原始信号,所以选项A错误。 选项B:正确。 选项C:这个是离散信号的定义,
关于吊顶工程施工工艺流程:①填充材料的安装;②吊杆安装;③安装收口压条;④龙骨安
对工程造价起着决定作用的是()。A.对特殊不良工程地质问题认识不足 B.施工
最新回复
(
0
)