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本月天象的主角是5颗肉眼可见的行星。水星和金星将分别达到西大距和东大距;火星、木星,以及土星的可见时间都是在后半夜,其中火星将在本月下旬分别与木星和土星相合,在10天左右的时间里它们彼此之间的角距离都很小。此外,矩尺座γ流星雨也将在3月迎来极大,但它更适合在南半球观测。 相似文献
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12月2日 凤凰座流星雨
12月的天象被三场流星雨主宰,首先来临的是我们几乎从没听说过,但是在今年却值得推荐的一场流星雨——凤凰座流星雨。
凤凰座流星雨是一个很奇怪又神秘的流星雨,它只在1956年12月5日爆发过一次,ZHR达到300,从那之后就销声匿迹,每年的ZHR只有1~5左右。而它的母彗星D/1819 W1(Blanpain)也只在1819年被观测到过一次。这些现象都给凤凰座流星雨蒙上了一层神秘的面纱。 相似文献
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Yang Chen Yu Bai Xiang-Tao He Jiang-Hua Wu Jing Wang Qing-Kang Li Yan-Chun Sun Richard F. Green Wolfgang Voges 《中国天文和天体物理学报》2007,7(4):595-600
We aim to provide a quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0〈B-J〈2.5,1.0〈 J-Ks 〈2.0 and 0.5〈H-Ks〈1.2. 相似文献
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The Third Peak of the 1998 Leonid Meteor Shower 总被引:2,自引:0,他引:2
1 INTRODUCTIONThe Leonid meteor shower is a well-known periodic meteor shower. Its history is tied upwith the development of the theory of meteor stream astronomy itself. It was the very st.rongshowers of 1799 and 1833 that played a sghficant pat in the recoghtion of the ealstence ofmeteoroid streams. These evellts started the obse~ions of Leoaid meteor shower and broughtabout the birth of meteoritiCS. It is known that the Leould parent comet, 55P/Tempel-TUttle,has an orbital period a… 相似文献
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Yu-Lan Yang Qing-Yao LiuNational Astronomical Observatories Yunnan Observatory Chinese Academy of Sciences Kunming United Laboratory of Optical Astronomy Chinese Academy of Sciences 《中国天文和天体物理学报》2004,4(6):553-562
Complete BV light curves of the W UMa type binary RT LMi are presented. From the observations, four times of minimum light were determined. Based on the new times of minimum light and those collected from the literature, changes in the orbital period of the system were found and analyzed with Kalimeris et al.'s method. The result shows that the orbital period possibly oscillates with a cycle of about 64 years and an amplitude of 1.2 × 10-6 days. The present CCD photometric observations reveal that the light curves are obviously asymmetrical, and show a positive O'Connell effect, while the light curves obtained in 1982 exhibit a negative O'Connell effect. The present light curves were analyzed by means of the latest version of the Wilson-Devinney code, which was also used to correct the photometric effects, including the distortion on the radial-velocity curves obtained by Rucinski et al. The following absolute dimensions have been derived: MI -1.28 ±0.08 M⊙, M2 = 0.48 ±0.06 M⊙, R1 = 1.28 ±0.06 R⊙, 相似文献
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又是一年的天象预报与您见面了,在接下来的12期里,我很荣幸能和大家一同见证2012年精彩的天象。同时,也希望有更多朋友通过天象预报开始关注天文,进行天文观测,并能从中收获更多的快乐。2012年虽然有很多值得关注的重要天象,但一月的天象剧场并没有给大家带来眼前一亮的感觉。象限仪流星雨是全年为数不多观测会受到月光干扰的大流量流星雨,而过近日点的P/2006 T1(levy)彗星预计也不会达到肉眼可见的亮度。只是金星、火星、木星和土星这几颗经典行星的观测条件还都不错,大家可以尽情发挥,拍些行星合月的天象照片。 相似文献