四月下旬天琴座流星雨分析和预测

四月下旬天琴座流星雨分析和预测
今年的天琴座流星雨活动从4月16日到27日，极大在出现在22-23日之间，国际流星组织给出的预报极大值在黄经 32.32度(北京时间22日19时)。每小时天顶流量18. 流星速度约为49km/s，颜色偏白，r=2.1所以亮流星比例较大。其中在21-24日极大时刻之外的时间群内流星活动规模为5颗/时，在这之外的时间，流星群活动微弱，每小时只能产生1-2颗群内流星
天琴座流星雨的ZHR值（极大时流星每小时天顶理论流量）在14至 23之间，算不上一个较大的流星雨。但在1982年，美国曾有该流星雨ZHR值达到90的观测记录。

有一种说法认为，这是由于天琴座流星雨的极大时间太短，很难被观测者捕捉到而引起的误差。如果我们把从20世纪早期的观测资料收集起来进行分析就会发现，天琴座流星雨的流量是在缓慢上升，也就是说它在逐渐 “成长”。可能有朝一日，它会成为一个流量大而稳定的流星雨。

Adurius Dubietis和Rainer Arlt曾在2001年总结了国际流星组织自1988-2000年的天琴座流星雨的报告，这也是现在关于这个流星雨最详细的报告了。他们找到了一些新鲜的特征，最重要的就是每年的极大黄经都在32.0-32.45度之间（在2004年对应的就是21日20时20分到22日7时20分），平均在32.32。虽然那13年中极大流量都在18左右，但有一些独立的峰值出现，最高和最低流量是23和14。（一个很短的高峰是1982年在美国监测到的，流量为90）。这些主要峰值的特征是短、迅速、大量，而研究显示该流星群的峰值长度也在不断变动。1993年为14.8小时而2000年为61.7小时，平均值为32.1小时。最好的峰值通常只出现很少时间。另外一个特征就是，确认了20世纪早期的猜想，就是当即大流量来临的时候，天琴座流星雨的暗弱流星数目就会增长。一切难料，每年的天琴座流星雨值得我们去观测，因此当下一个不寻常的峰值出现前我们不能对今年的流星雨枉下结论。
中国流星观测者联盟   67533285

呵，一屁股坐板凳！认识了！

希望是个晴天，好几天没有看到星星了

After a long - - - slow - - - February and March, April arrives with the
promise of Lyrid meteors. Moon conditions for the Lyrids this year is
pretty good, so start your plans now to get out one or two mornings
around their date of maximum. If you need some help on what to watch
for, or how to record the data, send me an email and I can send you some
instructional material via email.

This is a shower that could use all of our observations. The Lyrids have
shown some variability - in the time of their maximum, in the length of
their peak and in the numbers of meteors produced. So with all of this
unpredictability, there’s no telling what may happen when you are out
observing!

Using the large amount of data they have, the International Meteor
Organization predicts that the 2009 Lyrids will have the following
parameters:

Active: April 16-25
Maximum: April 22
ZHR: 18
Radiant: 18h 04m +34

If the IMO predictions hold true, the best place to be for catching peak
activity will be the Pacific Ocean and the extreme west of North
America. But as the IMO states on their website “other maximum times are
perfectly possible”. So don’t forget the Lyrids when making your plans
for April!

Good luck!!

--
Mark Davis, South Carolina, USA
meteors@comcast.net
namn@namnmeteors.org

North American Meteor Network
http://www.namnmeteors.org

一定要是晴天啊！！1

希望到時候天氣能轉好吧。這十多天都是多雲天氣，夠鬱悶的了。

忽忽 大家多多支持

The Lyrids (LYR) are the first major annual shower of the season. ZHR's
reach one on April 16th and remain at or slightly above this level through
April 27. According to the IMO calendar, peak rates will occur on Wednesday
April 22 near 11:00 Universal Time. This timing favors the western half of
North America where observers will have the radiant located high in a dark
sky, as long as you are not situated too far north where morning twilight
begins to interfere at this time. Sirko Molau's video data lists the peak on
the 23rd, so observers are encouraged to observe on both nights if possible.
ZHR's average eighteen but raw visual rates can vary from 5-25, depending on
your observing conditions. The radiant currently lies at 17:52 (268) +34.
This area of the sky is located in eastern Hercules, twelve degrees
southwest of the brilliant zero magnitude star Vega (Alpha Lyrae). The
radiant rises in the northeastern sky during the late evening hours for most
locations in the Northern Hemisphere. One should wait until the radiant
reaches an elevation of thirty degrees before commencing observations. At
lower radiant elevations only a small fraction of the Lyrid activity can be
seen. For 30 degrees north latitude this occurs near midnight. The radiant
would reach thirty degrees elevation earlier for locations further north and
later for locations further south. The best time to view this activity is
just before the start of morning twilight, when the radiant lies highest in
a dark sky. With an entry velocity of 46 kilometers per second, a majority
of these meteors will appear to move with moderate to swift speeds. The
Lyrids are also known to produce a fair amount of meteors with persistent
trains and an occasional fireball.

等吖等    希望能看到吧...

额    更期待宝瓶!!!!

额    更期待宝瓶!!!!
麦哲伦 发表于 2009-4-18 23:31

                               
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宝瓶可以连续几天产生ZHR》30 值得期待啊

顶

挖啊，，到时候要看宝瓶