拉帕尔马上空的流星、彗星和北斗七星
影像来源与版权:Vincent Duparc

说明:流星雨是由固体颗粒流引起的,成群的尘埃般大小和更大的颗粒在太空中移动。在大多数情况下,这些流星群的轨道可以通过彗星释放的尘埃来确定。当地球穿过流星群,这些颗粒在地球大气中燃烧时,它们会在夜空中留下明亮的流星余迹。流星轨迹都是互相平行的,像火车轨道一样,视觉效果使它们看起来好像来源于一个远处的辐射点。这幅合成的特征影像拍摄于一月份的象限仪座流星雨期间,地点是位于非洲西北海岸外的西班牙加那利群岛之一的拉帕尔马。象限仪座流星雨的辐射点在北斗七星勺柄下方可见。仔细观察还会发现维尔塔宁彗星的黯淡绿色彗发。今晚是美丽天琴座流星雨的极大期,从黑暗的地方、在晴朗天空中每小时可以看到数颗流星。
翻译:北京天文馆

Meteors, Comet, and Big Dipper over La Palma
Image Credit & Copyright: Vincent Duparc

Explanation: Meteor showers are caused by streams of solid particles, dust size and larger, moving as a group through space. In most cases, the orbits of these meteor streams can be identified with dust expelled from a comet. When the Earth passes through a stream, the particles leave brilliant trails through the night sky as they disintegrate in Earth’s atmosphere. The meteor paths are all parallel to each other, but, like train tracks, the effect of perspective causes them to appear to originate from a radiant point in the distance. The featured image composite was taken during January’s Quadrantid meteor shower from La Palma, one of Spain’s Canary Islands, off the northwest coast of Africa. The Quadrantids radiant is visible just below the handle of the Big Dipper. A careful eye will also discern the faint green coma of Comet Wirtanen. Tonight is the peak of the modest Lyrid meteor shower, with several meteors per hour visible from dark locations with clear skies.
Astronomy Picture of the Day 04/23/2019