本帖最后由 q零度星系 于 2011-12-19 14:26 编辑
月亮反光率79.3%，月亮距离辐射点有112度左右
1.来自国际流星组织 Quadrantids (QUA)1月4日15时20分象限仪座流星雨极大（通常120颗，但有时可能会有60到200颗，不过今年受月光较强，辐射点偏北，我国北方比南方观看更佳）
活动时段：12月 28日 — 1月 12日; 极大时期: 北京时间1月 4日, 15时20分 (λ⊙ = 283.16°);
ZHR = 120 (可能会变化到 ∼ 60—200);
辐射点: α 赤经= 230°, δ 赤纬= +49°; Radiant drift: see Table 6;
速度 = 41 km/s; r亮度指标 = 2.1 at maximum, but variable但是可变;
TFC: α = 242°, δ = +75° and α = 198°, δ = +40° (β > 40° N).
IFC: before 0h local time α = 150°, δ = +70°; after 0h local time α = 180°, δ = +40° and
α = 240°, δ = +70° (β > 40° N). |
Waxing gibbous moonset for the predicted Quadrantid maximum leaves several dark-sky hours for visual observing before morning twilight begins from northern hemisphere sites this year. From many such places, the shower's radiant is circumpolar, in northern Boötes, first attaining a useful elevation after local midnight, improving steadily later, making this a reasonably favourable return. Observing sites from eastern North America east to the extreme west of Europe should be best-placed to record what happens, if the maximum time above is correct. Modelling the stream is difficult. While the graph shown in HMO p. 129, based on computations by Jérémie Vaubaillon, seemed to suggest enhanced rates could happen between roughly 01h to 10h UT on January 4, his recent results do not support this. The λ⊙ = 283.16° maximum timing is based on the best-observed return of the shower ever analysed, from IMO data collected in 1992, as confirmed by radio results in most years since 1996. The peak itself is normally short-lived, and can be easily missed in just a few hours of poor northern-winter weather, which may be why the ZHR level apparently fluctuates from year to year. However, some genuine variability is probably present too. An added level of complexity comes from the fact mass-sorting of particles across the meteoroid stream may make fainter objects (radio and telescopic meteors) reach maximum up to 14 hours before the brighter (visual and photographic) ones, so observers should be alert throughout the shower. A few years since 2000 seem to have produced a, primarily radio, maximum following the main visual one by some 9—12 hours. Visual confirmation of any repeat of such behaviour would be welcomed. QUA activity tends to be very low more than a day or so from the peak, and past observations have suggested the radiant is diffuse away from the maximum too, contracting notably during the peak itself, perhaps because of this lower activity then. Imaging observations would be welcomed to help investigate this topic, along with telescopic results. 2.由IMCCE提供的流星体轨道数据图
3.来自seasky.org
3到4日每小时40颗流量值
4.来自香港天文学会(仅供参考）
相關流星群 ：象限儀座流星雨 (QUA)
出現日期 ：2011年12月28日至2012年1月12日
極大日期(香港時間)：1月4日(星期三)15時16分
天頂每時出射率 ZHR：120 顆 (可能 60 至 200顆)
速度 ：每秒 41千米(中速)
亮度指標 ：2.1
輻射點 (曆元 2000)：赤經 15.3時/230.1°赤緯 48.5°
IMO 象限儀座流星雨 (QUA) 輻射點位置移動星圖
流星出現的情況受到預測流星雨極大時刻是否在日間還是晚上，流星體是否正面射向地球或者背向地球，月亮的位置及天空雲量所影響，觀測地點實際情況與極大時刻須參考當地預報
注意：流星雨的高峰期時間，因觀測條件關係，很多時並非與香港出現流星雨的高峰時間一致。地球、月球及流星體的相對位置亦令月閃(流星撞擊月面產生的閃光)的預報高峰時刻與地球的流星雨預測高峰期有時間差異！
象限儀座是個已經廢棄的星座，流星雨原名天龍座流星雨，為免與十月出現的天龍座流星雨混淆，採用個廢棄了的星座來命名，亦是國際天文聯會(IAU)唯一的一個用不存在星座名命的流星雨。它的輻射點位於現今的牧夫座。
香港預測
高峰時間: 1月4日(星期三)15時16分
高峰期間: 1月4日凌晨3時至6時30分
高峰時天頂每時出射率ZHR估計每小時可見流星數:
1月4日(星期三)凌晨6時06分
市區: 1至2 顆; 市郊: 8 顆; 鄉郊: 15至16 顆; 很黑地區:22 顆
1月4日
月 落：2時28分 (月齡十一)
天文曙光: 5時44分
航海曙光: 6時12分
民用曙光: 6時40分
日 出：7時04分
| 
,当Kp指数达到6或以上时，我国境内有可能观察到极光；当前极光活动水平
，极光为9时漠河可能见极光，
级，当地磁暴级别达到G2或以上时，我国境内有可能见极光
置顶卡
变色卡
千斤顶
显身卡
