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991.
We will present detailed observations of the asymmetrical eruption of a large quiescent filament on 24 November 2002, which was followed by a two-ribbon flare, three coronal dimmings, endpoint brightenings, and a very fast halo-type coronal mass ejection (CME). Before the eruption, the filament lay along the main neutral line (MNL) underneath a single-arcade helmet streamer with a simple bipolar configuration. However, photospheric magnetic fields on both sides of the filament showed an asymmetrical distribution, and the filament and MNL were not located just at the center of the streamer base but were closer to the eastern leg of the streamer arcade. Therefore, instead of erupting along the streamer’s symmetrical axis, the filament showed a nonradial and asymmetrical eruption. It lifted from the eastern flank of the streamer arcade to impact the western leg directly, leading to an asymmetrical CME that expanded westward; eventually the streamer was disrupted significantly. Accordingly, the opposite-polarity coronal dimmings at both sides of the filament forming in the eruption also showed an asymmetrical area distribution. We thus assume that the streamer arcade could guide the filament at the early eruption phase but failed to restrain it later. Consistent with previous results, these observations suggest that the global background magnetic field can impose additional action on the initial eruption of the filament and CME, as well as the dimming configuration. 相似文献
992.
台站设备故障响应和风险排除是地震监测工作的基本内容,针对其便捷性和高时效性要求,采用Java语言,开发基于Android平台的地震地球物理数据监控软件。该软件整合重庆市地震局监测工作中的各项业务需求,采用云服务、Tomcat服务器及百度地图等技术,实现了数据实时查看及历史数据波形浏览等功能,及时获取仪器设备工作状态,及时发现设备故障并进行维护,工作效率得以提高。 相似文献
993.
1 研究背景
地震活动断层不同区段和时段均具有不同的力学特性,主要是表现在活动断层上发生地震的断层段所呈现的震前、同震、震后和震间4个时域范围内的滑动行为.换言之,地震活动断层的滑动行为分为震前、同震、震后和震间4个滑动阶段.通过研究活动断层地震破裂段震前、同震、震后和震间滑动,可深入破解沿活动断层破裂段的应力、应变的积累和释放的时空信息变化(Reilinger et al,1999;Yagi et al,2001;Ozawa et al,2004). 相似文献
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Error analyses are made of ACR (Astrometric Calibration Regions along the celestial equator) and CMC13 (Carlsberg Meridian Catalogue 13), two astrometric catalogues compiled on the basis of CCD drift scanning observations and published respectively before and after 2000. Through a comparison with the UCAC2 (the second U.S. Naval Observatory CCD Astrograph Catalogue), the form and size of the errors are analyzed numerically. The main and possible sources of the errors are analyzed from the standpoint of observing mode and data reduction. It is found that there is evident magnitude difference between the ACR and CMC13 in the equatorial direction, and that there exists periodic variation close to the CCD field of view along the right ascension and also a systematic variation close to the size of reduction zone along the declination. 相似文献
999.
Jian-Ning Fu Chao Zhang Kanokwan Marak Chayan Boonyarak Pongsak Khokhuntod Shi-Yang Jiang 《中国天文和天体物理学报》2008,8(2):237-244
New time-series photometric observations of BL Cam in the V band and white light were made during 2005 to 2007 at the Xinglong Station of China. The frequency analysis confirms two closely separated frequencies, 25.181 d-1 and 25.571 d-1, but the frequency of 31-32 d-1 reported in the literature was not detected in the new data. New times of maximum light were determined from both our light curves and those available on Internet, allowing a more comprehensive study of the O - C diagram, together with the times of maximum light in the literature. A new interpretation, including the period increasing before 1988 and decreasing since 1992 of BL Cam and the light-time effect in a binary system, looks plausible. 相似文献
1000.
By using Hα, He I 10830, EUV and soft X-ray (SXR) data, we examined a filament eruption that occurred on a quiet-sun region near the center of the solar disk on 2006 January 12, which disturbed a sigmoid overlying the filament channel observed by the GOES-12 SXR Imager (SXI), and led to the eruption of the sigmoid. The event was associated with a partial halo coronal mass ejection (CME) observed by the Large Angle and Spectrometric Coronagraphs (LASCO) on board the Solar and Heliospheric Observatory (SOHO), and resulted in the formation of two flare-like ribbons, post-eruption coronal loops, and two transient coronal holes (TCHs), but there were no significantly recorded GOES or Hα flares corresponding to the eruption. The two TCHs were dominated by opposite magnetic polarities and were located on the two ends of the eruptive sigmoid. They showed similar locations and shapes in He Ⅰ 10830, EUV and SXR observations. During the early eruption phase, brightenings first appeared on the locations of the two subsequent TCHs, which could be clearly identified on He Ⅰ 10830, EUV and SXR images. This eruption could be explained by the magnetic flux rope model, and the two TCHs were likely to be the feet of the flux rope. 相似文献