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一个与大麦哲伦云的日食二进制距离,准确度为2%
G Pietrzyński1, D Graczyk, W Gieren
1Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción, Chile. pietrzyn@astrouw.edu.pl
Nature
|March 8, 2013
概括
天文学家准确地测量到大麦哲伦云的距离,使用冷的日食双星. 这提高了哈勃恒定的精度,这对于理解宇宙膨胀至关重要.
科学领域:
- 宇宙学的宇宙学是什么?
- 天体物理学 天体物理学
- 恒星天文学 恒星天文学
背景情况:
- 准确地确定哈勃常数对于精确的宇宙学至关重要.
- 哈勃恒定的不确定性目前受到大马格伦云 (LMC) 距离的限制.
- 阴影二进制星系是精确的恒星参数和距离测量的宝贵工具.
研究的目的:
- 为了更准确地确定大麦哲伦云 (LMC) 的距离.
- 为宇宙距离尺度提供一个更可靠的.
- 为了能够更精确地确定哈勃常数.
主要方法:
- 在LMC中研究了八个长周期,晚期类型的日食双星系统,由冷却的巨星组成.
- 准确测量了二进制组件的线性和角度尺寸.
- 避免了与模拟热,早期类型的日食系统相关的复杂性.
主要成果:
- 推导出一个LMC距离为49.97 ± 0.19 (统计) ± 1.11 (系统) 千分秒.
- 对于LMC来说,实现了2.2%的距离精度.
- 这一结果为哈勃常数的3%的确定提供了坚实的基础.
结论:
- 使用后期类型的日食二进制系统为LMC距离的确定提供了更准确的方法.
- 改进的LMC距离显著减少了哈勃恒定计算中的关键不确定性.
- 未来的前景表明,哈勃恒定测量的准确度可能会更高 (2%).
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