英仙座流星

2020年8月10日

Perseids from Perseus
Image Credit & Copyright: Petr Horálek

Explanation: Where are all these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tomorrow night is known as the Perseids — the meteors all appear to came from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris that makes up the Perseids meteors come from Comet Swift-Tuttle. The comet follows a well-defined orbit around our Sun, and the part of the orbit that approaches Earth is superposed in front of the Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Featured here, a composite image taken over eight nights and containing over 400 meteors from last August’s Perseids meteor shower shows many bright meteors that streaked over Kolonica Observatory in Slovakia. This year’s Perseids holds promise to be one of the best meteor showers of the year.

Tomorrow’s picture: high on jupiter

英仙座流星
影像提供与版权: Petr Horálek

说明: 这些流星是打那里来的？依在天空的方向来说，答案是英仙座。因为这些英仙流星看似全都源自英仙座方向的辐射源，而这也是为何极大期在明晚的这群流星，称为英仙流星雨的原因。然而，依它们的母源来论，形成英仙流星的沙粒大小碎片来自史威福-塔托彗星。这颗彗星有绕行太阳的明确轨道，而轨道靠近地球的部分就出现在英仙座前方。因此，每当地球穿过这个轨道，碎片洒落的辐射点就出现在英仙座方向。上面这幅组合8个晚上数据的主题影像，记录了去年8月英仙流星雨的400多颗流星，包括许多掠过斯洛伐克柯罗尼卡天文台上空的明亮流星。今年的英仙流星雨，有可能是今年最活跃的流星雨群之一。

明日的图片: high on jupiter