APOD090817：英仙座流星雨

最近几天大家拍了不少流星雨吧，17日的APOD也是流星雨
http://apod.nasa.gov/apod/ap090817.html    美洲网站今天都很慢，所以图就不贴APOD原图了。

Perseids from Perseus

                               
登录/注册后可看大图

Credit & Copyright: Chris Peterson (Cloudbait Observatory)
Explanation:
Where are all of these meteors coming from?  In terms of direction on the sky, the pointed answer is theconstellationof Perseus.  That is why the last week's meteor shower was known as thePerseids -- the meteors all appear to come from aradiant toward Perseus.Three dimensionally, however,sand-sized debrisexpelled from Comet Swift-Tuttlefollows a well-defined orbit about our Sun, and the part of the orbitthat approaches Earth is superposed in front of the Perseus.Therefore, when Earth crosses this orbit, theradiant point of falling debris appears in Perseus.Pictured above, a composite image of this year'sPereids meteor shower shows manybright meteors thatstreakedthrough the sky on August 12.  To the surprise of many, the next night, August 13, also showedmany meteors, as demonstrated by rolling one's cursor over the above image.This year'sLeonids meteor showerin November isexpected by some to be exceptionally active,perhaps producing as many as 500 meteors per hour.

今天的大图就这么大，这是北京天文馆的翻译
http://www.bjp.org.cn/apod/2009-08/17/content_9482.htm

英仙座流星雨

                               
登录/注册后可看大图

影像提供及版权：Chris Peterson (Cloudbait Observatory)
说明：
这些流星都是从哪里来的？按照天空中的方位，那里正是英仙座的方向。这就是为什么上周发生的流星雨被称为英仙座流星雨的原因，所有的流星看上去都来自英仙座的辐射点。然而就三维立体来看，从斯威夫特-塔特尔彗星喷出来的沙粒状碎片沿着预定的轨道绕太阳运行，轨道的一部分正好靠近地球，并且与英仙座方位恰好重叠。因此，当地球靠近这段轨道时，从辐射点落下的碎片就形成了英仙座流星雨。上面的影像是今年英仙座流星雨的合成影像，其中显示了在8月12日，有许多明亮的流星划过夜空。令人惊奇的是在第二晚，8月13日还有许多流星出现，将你的鼠标放在影像上面就会出现新的场景。今年11月的狮子座流星雨可能会异常活跃，每小时可能会出现500颗。

没看明白 你拍的这真是流星雨吗？

3# wdmir

首先，这不是LZ拍的；其次，这确实是流星雨，只不过是合成的。