「利用者:Kovayashi/sandbox5」の版間の差分

 

重力レンズ現象は、遠方の物体と巨大な中間物体が地球から見て直線を形成するときに起こる。このとき、中間天体の重力場が遠方の天体からの光を曲げ、それを拡大する。2つの物体が銀河ではなく星である場合、これは重力マイクロレンズと呼ばれています。この配置は非常に正確でなければならず、実際にはアルバート・アインシュタインが「この現象を観測する可能性はほとんどない」と結論づけたほどです。しかし、光学重力レンズ実験（OGLE）などの現代の調査では、毎晩何百万個もの星を観測しており、年に何度もマイクロレンズ現象が観測されています。

 

Since the alignment must be so precise, if the event lasts more than a few weeks, scientists can observe changes as the Earth moves around the sun, since this movement changes the alignment. Traditionally in astronomy, a change in view caused by the Earth's motion is called parallax, and this is the term used by researchers for this effect. However, if the source star is part of a binary system, then it too has orbital motion, and this can modify the alignment just as the Earth's movement can. Since both effects are caused by the effect of orbital motion on alignment, they are very closely related. And since the effect is the same as parallax, just backwards (from the motion of the source rather than motion of the observer) it was called xallarap. The name stuck, and is now commonly used in astronomical literature.