The age difference between the oldest Population I stars and the extreme Population II stars is investigated by comparison of observational H-R diagrams with theoretical results using the common input physics and computer program for both Populations. Chemical compositions adopted for Population I and ...
4.According to paragraph 2, Population I stars and Population II stars differ from each other in terms of both A. how old they are and where in their galaxies they are found B. how old they are and whether they have a halo around them C. where in their galaxies they are found ...
Population II stars are the old metal poor stars that form the halo of the galaxy. Globular clusters are population II objects. Population I stars are younger and more metal rich. They form the disk of the galaxy. The sun is an intermediate age population I star. Figure 12a is an ...
Deficiency of Metals in Population II StarsWallersteinobjectionsproposalsBurbidgeTHE objections raised by Wallerstein and Burbidge to my proposals are themselves subject to question.doi:10.1038/2001082a0STANLEY BASHKINNature
网络释义 1. 第二类星族 我们现在看到的最古老的恒星,称为第二类星族(Population II stars) ,应该是稍微晚一点才形成的第二代恒星。和类似太阳的 … tw.knowledge.yahoo.com|基于2个网页
One finds that such Pop III stars are mainly characterised by a decreased upper limit for the appearance of electron degeneracy in the core of H-shell burning structures and by an increased upper limit for the occurrence of degenerate CO cores, both these occurrences being the result of the ...
而在宇宙刚诞生的时候,有一批刚诞生的恒星,这类恒星的金属元素含量为0,它们只比宇宙年轻一点,这类恒星被叫做第三星族星(星族III,Population III stars)。 目前来说,第三星族星是一类假想中的天体,科学家还未发现此类天体,虽然也发现了一些早期恒星,比如HE 0107-5240,它的年龄大约有130亿年,是人类发现的最古老的...
each of three groups (designated I, II, and III) into which stars can be approximately divided on the basis of their manner of formation (4).韦伯斯特词典communitypopulation Common possession or enjoyment; participation; as, a community of goods. ...
I.根据语境用括号内所给单词的适当形式填空。1. Ther e are(billion) of stars in th e sky.2. Th e population of this city (grow) by 5% last year.3. Whil e I was doing my homework, Mum was(prepare)dinner.4. Only one e (five) of th e students in my class exercis e every day...
the latter being much older than the former.These groups can also be distinguished by their locations.Our galaxy, the Milky Way, is shaped like a flat disk surrounding a central bulge.Whereas Population I stars are found mainly in the galactic disk, Population II stars mostly reside in the ...