查看“︁愛因斯坦環”︁的源代码

{{noteTA
|G1=物理学
}}
{{Gravitational Lensing}}
[[File:Close-up of the Einstein ring around galaxy NGC 6505 ESA506346.jpg|right|thumb|由[[歐幾里得太空望遠鏡]]所觀測到的 [[NGC 6505]]愛因斯坦環]]

'''愛因斯坦環'''（{{lang-en|Einstein ring}}）是指一種由於光源發出的光線受到[[引力透鏡效應]]的影響，而使觀測所得的光源形狀改變的現象。

== 原理 ==
愛因斯坦環是由[[廣義相對論]]所預測的現象。

愛因斯坦環的大小是由{{le|愛因斯坦半徑|Einstein radius}}決定：

: <math>\theta_1 = \sqrt{\frac{4GM}{c^2}\;\frac{d_{LS}}{d_L d_S}},</math>

其中<math>G</math>是[[万有引力常数]]，<math>M</math>是透鏡星體的質量。<math>c</math>是[[光速]]，<math>d_L</math>是透鏡星體的[[角直徑距離]]，<math>d_S</math>是來源的角直徑距離，<math>d_{LS}</math>是兩者的角直徑距離。

== 歷史 ==
[[File:Einstein_Rings.jpg|thumb|300px|right|觀測所得的照片。]]
[[File:ALMA image of the gravitationally lensed galaxy SDP.81..jpg|thumb|150px|right|SDP.81]]
[[File:HST-Smiling-GalaxyClusterSDSS-J1038+4849-20150210.jpg|thumb|300px|right|宇宙大笑脸<ref name="NASA-20150210">{{cite web|title=Hubble Sees A Smiling Lens|url=http://www.nasa.gov/content/hubble-sees-a-smiling-lens/|accessdate=2015-02-10|date=2015-02-10|work=[[NASA]]|archive-url=https://web.archive.org/web/20150211033335/http://www.nasa.gov/content/hubble-sees-a-smiling-lens/|archive-date=2015-02-11|dead-url=no|last1=Loff|first1=Sarah|last2=Dunbar|first2=Brian}}</ref>]]
[[Image:SDSSJ0946+1006.jpg|thumb|right|SDSSJ0946+1006 ]]
[[File:A Horseshoe Einstein Ring from Hubble.JPG|thumb|300px|right|SDSS J114833.14+193003.2]]

== 參見 ==
{{Commons category|Einstein Rings}}
* {{le|愛因斯坦半徑|Einstein radius}}
* [[爱因斯坦十字]]
* [[引力透镜]]

== 延伸閱讀 ==
*{{Cite journal|title=The Importance of Einstein Rings|url=https://iopscience.iop.org/article/10.1086/318350|last=Kochanek|first=C. S.|last2=Keeton|first2=C. R.|date=2001-01-20|journal=The Astrophysical Journal|issue=1|doi=10.1086/318350|volume=547|pages=50–59|language=en|issn=0004-637X|last3=McLeod|first3=B. A.|access-date=2021-10-12|archive-date=2022-04-08|archive-url=https://web.archive.org/web/20220408021226/https://iopscience.iop.org/article/10.1086/318350}}

== 参考 ==
{{reflist}}
{{astro-stub}}
[[Category:引力]]
[[Category:重力透鏡]]
[[Category:光学现象]]
[[Category:阿尔伯特·爱因斯坦]]
[[Category:引力波]]