天文科普《两星绕转目击回忆录》

Memorizing the witness of two stars rotating each other
YuDingyu/YuDingwen

有一天晚上，我们在户外，抬头看见满天星星，像海滩上的沙子，一层压一层的。这时，有一颗星星(为行文方便起见，我们不妨把这颗星星叫做A星）突然移动起来，并逐渐加快。当它移到另一颗星星（我们把这颗星星叫做B星）的一侧时，这两颗星星顺势互相环绕，各绕了半周，A星绕到了B星的另一侧。然后,A星又顺势返回去了，并逐渐减慢，最后停在它起动的位置附近。

One evening, I rambled outside to feel the quiet atmosphere and watched numeral stars twinkling on the sky. Suddenly, I noticed that one star (for convenience we call the star as star A) started to move. It moved slowly at the beginning and getting faster. When it moved close to another star (we call this star as star B) the two stars started to go around each other for a half circle. Star A moved to the other side of star B, and then moved back in the coming direction with gradually reduced speed, and finally stopped at nearly the original position.

两星的起始距离约为月面直径，走过这段距离所用的时间约为5秒。A星沿半圆弧的近似切线，做加速运动。同时，B星也有少许与A星相向的运动，其速度和距离大约都是A星的四分之一幅度。环绕时两星在同一条旋扫直径的两端，距离约为月面直径的五分之一，环绕半周所用的时间约为1秒，画出的两段弧近似于两个半圆弧，A星画的是大弧，B星画的是小弧，很像运动员抛链球时的旋转。两星返回的最后距离约为月面直径，返回所用的时间约为5秒。A星返回方向与移过来的方向相反，沿半圆弧的近似切线，做减速运动，很像刚抛出去的链球。同时，B星也有少许与A星相背的运动，其速度和距离大约都是A星的四分之一幅度。A星的整个运动轨迹很像自行车的链条，B星的轨迹很像一只鸡蛋。最终两星都停在它们各自起动的位置附近，就再也不动了，很长时间两星都不动了。

The distance between the two stars before star A moved looked like the same as the diameter of the moon. It took star A about five seconds to move through this distance. The star A moved along the tangent of its half-circle locus and with increasing speed. At the same time, star B also moved toward star A for a quarter of the distance that star A moved, and the speed is also about a quarter of that of star A. When they were moving around each other, they were at the two ends of a diameter of the circle locus, and the distance between them were about one fifth of the diameter of the moon. It took about 1 second for them to move for a half circle, and their locus were nearly two half circles. Star A draw a big circle while star B draw a small circle, both of which were similar to the hammer that was threw out by an athlete. At the same time, star B had also movement away from star A, and both the distance and the speed were about a quarter of that of star A. The whole moving locus of star A were very similar to the chain of a bicycle, whilst the whole moving locus of star B was similar to an egg. Finally, the two stars stopped at near their original positions and never moved again for quite a long observing time.

该天文现象发生的时间大约是1965年，12月份，某一天晚上20点左右（北京时间）。观测地点在中国长春市郊区(约东经125度，北纬44度）。该双星在天空中的位置接近正东方向，距天顶约20度。A星移过来时的运动方向接近自北向南，返回去时的运动方向接近自南向北。环绕可能是反时针方向。这两颗星的亮度接近相等，不是很亮，但肉眼可以清楚看见。整个运动过程及其后很长时间，两星的亮度都没有变化。

It was about 8 o’clock in the evening of Beijing time in December 1965 when this astronomic phenomenon was happen to be observed, but the exact date could not be recalled. The observing place was in the suburb of Changchun (the altitude is about 125oeast and the latitude 44o north), in the northeast of China. The location of the two stars in the sky is described as of 70o above the horizontal in the east. The approaching direction of star A to the star B was from the north to the south, and the returning direction was from the south to the north. The direction of the moving around a circle was probably anti-clockwise. The brightness of the two stars was similar and was not very bright, but could be seen clearly by the naked eyes. The brightness of the two stars were not changed during the whole observing process.

由于当时对此天文现象认识不足，没有刻意记录准确的时间，也没有测量天区及认定星座，拖延的时间太久，以至削弱了其应有的科学价值，笔者深表歉意。这两颗星现在还在天上挂着，天气晴朗时，肉眼仍能看到，只是笔者已认不准是哪两颗了。任何现象都会留下蛛丝马迹，有兴趣的朋友可以根据本文提供的线索跟踪观测，最终一定会把这两颗星找到的。即使绕转偏心率越大，周期越长，也总会有个周期吧。如果能对下次绕转做出预报，让大家都能目睹这一奇观，不失为爱好者的一件幸事。

Due to the lack of knowledge in the field of astronomy at the time, the author neither recorded the exact happening time, nor measured the location area. The name of the star system was also not identified. After so long time, the academic value of the observation, which is supposed to be significant, may be degraded, for which the author feel deeply sorry. It is believed that the two stars are still on the sky and should be seen at night when it is clear, but the author is not sure which two they are. However, there must be some traces left if anything happened in the universe. Therefore, any people having interests could make observations following the information provided here. And I believe that the two star would be found finally. Through a big eccentricity will result in a long cycle of this star system movement, the cycle is a finite value. If it can be predicted for the time of next movement of the two star system, it would be fantastic for all the interested people to have chance to observe this wonder of the universe.