2009年猎户座流星雨观测指导

Viewing Activity from the 2009 Orionid Meteor Shower
来源：American Meteor Society   编译：贪星鬼

    下一个主要的流星雨将出现在10月。著名的猎户座流星雨是已知的两个与哈雷彗星有关的流星雨之一。这场流星雨活跃在整个10月和11月第一周。极大发生在10月21日，通常平均每小时10-15颗群内流星。然而，最近猎户座流星雨也相当强劲，可以匹敌8月的的英仙座流星雨。流星群将产生火流星，明亮的流星超过金星的亮度。
    猎户座流星雨从9月28日开始出现。随着最大活动日期的临近流量缓慢增加。月亮影响要持续到10月11日，当它达到下弦为止。从10月11日到18日，月光影响逐渐减小。 10月18日，月亮将达到新月，清晨的天空将看不到月亮，这种情况会持续到10月25日。10月19日星期一，流星群活动开始增大，两天后达到极大。由于没有尖锐的峰值，整整一周的10月19日应该产生很好的猎户座流星雨活动。未来两个星期将看到越来越少猎户座流星雨活动，特别是接近11月2日满月。该猎户座流星雨将于11月10日结束，正是狮子座流星雨将要开始的时候。
    猎户座流星雨辐射点，直到当地时间22：00（晚上10:00）才升出地平线。由于辐射点比较接近地平线，这时候的猎户座流星雨流量较小。直到午夜活动逐渐增强在当地时间5：00 达到高潮。因为辐射点高度降低，所以在高潮之后和在天文晨光开始的时间内流量将缓慢下降。为了更好的观测猎户座流星雨，就需要选择辐射点足够高的时间进行。将辐射点放在视场边缘比直视辐射点能看到更多的流星。因为辐射点附近的群内流星在这部分的天空看到将是最短的，可能被错过。猎户座流星雨期间还有其他几个小流星群在活动。西面的金牛座流星群每小时将产生几颗慢速的流星。期间双子座Epsilon流星群和狮子座流星雨群的活动还更微弱，辐射点位置更靠东，每小时约辐射一颗流星。它们都生产类似猎户座流星群那样快速的流星。
       10月初，辐射点在猎户座头部的北面。到了21日辐射点已漂流到猎户手中棒子的附近即猎户座/双子座的边界。最大的活动后，辐射点进入的双子座西南部直到流星群活动结束。由于辐射点接近天赤道，所以南北两个半球都可以观测这个流星雨。北半球略有优势，辐射点地平高度更大（取决于您的纬度）而且10月份北半球夜晚更长。
    这些流星进入地球的大气层，因此，大多会在天空中快速划过。例外情况将出现辐射点接近地平线时。猎户座流星雨的母体是哈雷彗星，但现在哈雷彗星的轨道并没有和地球相交，所以我们观测到的猎户座流星雨是数百年前哈雷彗星通过地球轨道时产生的。

10——15颗，还是比较少啊

老天给个好天气吧、、、、、、、、、

秋天的雨水较少,应该天气好些. 数量虽少,但是火流星可以期待.

想看啊

相比较英仙座，数量少多了

赶快买个遥控器去....哈哈 准备继续守星...

我也是错过了英仙。。。。
我不看猎户。。咱要等狮子 和双子

Orionids (ORI)

Active:	October 2-November 7
Maximum:	October 21 (λo = 208°)
ZHR =	30
Radiant:	α = 095° δ = +16°
Radiant drift:	see Table 6
v∞ =	66 km/s; r = 2.4
TFC:	α = 100° δ = +39° and α = 075° δ = +24° (β > 40° N)
\in	or α = 080° δ = +01° and α = 117° δ = +01° (β < 40° N)

October's new Moon also perfectly favours the Orionids at their peak in 2009. The shower's radiant, near the celestial equator, is at a useful elevation by around local midnight in either hemisphere, somewhat before in the north, so most of the world can enjoy the shower. Both 2006 and 2007 produced unexpectedly strong Orionid rates, with ZHRs better than the normal peak seen on two or three consecutive nights, at best up to 50-70. The 2006 return also produced a good number of bright Orionids. IMO analyses of the shower, most recently by Jürgen Rendtel using data from 1979-2006, have found both the peak ZHR and r parameters varied somewhat from year to year, but with maximum ZHRs usually around 20-25, and an average r of 2.4. An earlier IMO examination by Audrius Dubietis seemed to partly confirm a suspected 12-year periodicity in stronger returns found earlier in the 20th century. That would suggest better returns again in the 2008-2010 interval, thus perhaps best ZHRs should be around 30 this year. The strong 2006-07 returns seem to have had a separate resonant cause, and a further enhancement was anticipated for 2008 (still to come when this was prepared). However, this was not expected to repeat in 2009, so it will be particularly interesting to see what takes place this time. The Orionids were always noted for having several lesser maxima other than their main one, helping activity sometimes to remain roughly constant for several consecutive nights centred on this peak. In 1993 and 1998, a submaximum about as strong as the normal peak was detected on October 17/18 from Europe, for instance. All observers should be aware of these possibilities, as observing circumstances are equally favourable for covering October 17/18 beneath dark skies this time too. Several visual subradiants had been reported in the past, but recent video work suggests the radiant is far less complex; photographic, telescopic and video work to confirm this would be useful, as visual observers have clearly had problems with the shower's radiant determination before.

有兴趣的朋友不要错过哈

我比较期待狮子座跟双子座流星雨~~

好像数量不多嘛

有长春的朋友一起去净月住2天看流星雨吗。我带镜子。顺便看看银河。不过气温估计冷死了。。接近0度。

是啊，数量太少了

期待一下

很期待！~~~~~~~~

10——15颗，还是比较少啊
yzbdt 发表于 2009-8-27 13:49

                               
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你知足吧，平稳上百的流星群只有3个，能有60左右的也只有几个，能有20左右已经非常不错了，平常经常发生的ZHR只有1到几，甚至几小时1颗也不奇怪。