“2019年IAO理论高年组第2题-年度NGC天体”的版本间的差异
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==英文题目== | ==英文题目== | ||
'''2.''' NGC of the Year. NGC 2019 is a globular cluster in the constellation Mensa, observed against the background of the Large Magellanic Cloud. The cluster has a visible magnitude m = 10.9<sup>m</sup> ， colour index B—V = 0.04<sup>m</sup> ， and is located at a distance of approximately L = 50 kpc from us. To the right you can see a 4 × 4 arcmin negative picture NGC 2019 ． Assume that the cluster consists for the most part of approximately the same stars located on the main sequence ， as well as a small percentage of white dwarfs, and that all these stars are more or less evenly distributed in the space Of the central "sphere" region, the image of which is clearly visible in the center of the image against the background Of the LMC. Estimate, at What distance from the center of the cluster an observer needs to be located in Order to distinguish separately the white dwarfs visible in the projection on the center of the cluster with the naked eye. | '''2.''' NGC of the Year. NGC 2019 is a globular cluster in the constellation Mensa, observed against the background of the Large Magellanic Cloud. The cluster has a visible magnitude m = 10.9<sup>m</sup> ， colour index B—V = 0.04<sup>m</sup> ， and is located at a distance of approximately L = 50 kpc from us. To the right you can see a 4 × 4 arcmin negative picture NGC 2019 ． Assume that the cluster consists for the most part of approximately the same stars located on the main sequence ， as well as a small percentage of white dwarfs, and that all these stars are more or less evenly distributed in the space Of the central "sphere" region, the image of which is clearly visible in the center of the image against the background Of the LMC. Estimate, at What distance from the center of the cluster an observer needs to be located in Order to distinguish separately the white dwarfs visible in the projection on the center of the cluster with the naked eye. | ||
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==中文翻译== | ==中文翻译== | ||
'''2.'''年度NGC天体。NGC2019是一个位于山案座的球状星团，位于背景的大麦哲伦云前方。这个星团目视星等m = 10.9，色指数B—V = 0.04，与我们的距离大约是L = 50 kpc。右边的照片是4×4角分视场的负片。假设这个球状星团大部分由主序上差不多位置的恒星和小部分白矮星组成，并且这些星基本是均匀分布在中心“球”内的，如图所示。估计，观测者需要在什么距离观测，才可以在朝向星团中心的方向上用肉眼单独区分出白矮星？ | '''2.'''年度NGC天体。NGC2019是一个位于山案座的球状星团，位于背景的大麦哲伦云前方。这个星团目视星等m = 10.9，色指数B—V = 0.04，与我们的距离大约是L = 50 kpc。右边的照片是4×4角分视场的负片。假设这个球状星团大部分由主序上差不多位置的恒星和小部分白矮星组成，并且这些星基本是均匀分布在中心“球”内的，如图所示。估计，观测者需要在什么距离观测，才可以在朝向星团中心的方向上用肉眼单独区分出白矮星？ | ||
2020年3月19日 (四) 19:32的版本
英文题目
2. NGC of the Year. NGC 2019 is a globular cluster in the constellation Mensa, observed against the background of the Large Magellanic Cloud. The cluster has a visible magnitude m = 10.9m ， colour index B—V = 0.04m ， and is located at a distance of approximately L = 50 kpc from us. To the right you can see a 4 × 4 arcmin negative picture NGC 2019 ． Assume that the cluster consists for the most part of approximately the same stars located on the main sequence ， as well as a small percentage of white dwarfs, and that all these stars are more or less evenly distributed in the space Of the central "sphere" region, the image of which is clearly visible in the center of the image against the background Of the LMC. Estimate, at What distance from the center of the cluster an observer needs to be located in Order to distinguish separately the white dwarfs visible in the projection on the center of the cluster with the naked eye.
中文翻译
2.年度NGC天体。NGC2019是一个位于山案座的球状星团，位于背景的大麦哲伦云前方。这个星团目视星等m = 10.9，色指数B—V = 0.04，与我们的距离大约是L = 50 kpc。右边的照片是4×4角分视场的负片。假设这个球状星团大部分由主序上差不多位置的恒星和小部分白矮星组成，并且这些星基本是均匀分布在中心“球”内的，如图所示。估计，观测者需要在什么距离观测，才可以在朝向星团中心的方向上用肉眼单独区分出白矮星？
