40m天线面板调试与精度分析

总结了40m天线面板安装调试及检测的过程，分析了反映望远镜面板指标的吨性能检测结果。结果表明天线面板精度优于原设计要求。     

The Relation between the Amplitude and the Period of Solar Cycles

The maximum amplitudes of solar activity cycles are found to be well anti-correlated (r = -0.72) with the newly defined solar cycle lengths three cycles before (at lag -3) in 13-month running mean sunspot numbers during the past 190 years. This result could be used for predicting the maximum sunspot numbers. The amplitudes of Cycles 24 and 25 are estimated to be 149.5±27.6 and 144.3±27.6, respectively.     

CCD Photometry of Asteroid （147） Protogeneia

We measured the light-curve of the asteroid (147) Protogeneia in November 2004, with a CCD detector attached to the 1-meter telescope at the Yunnan Observatory, China. The synodic period and maximum amplitude of (147) at this apparition are 7.852 hours and 0.25 mag, respectively. The value of a/b for (147), from a preliminary estimation, is not less than 1.26:1.     

Fiber Fine Structures Superposed on the Solar Continuum Emission Near 3 GHz

On April 21, 2002, a broadband solar radio burst was observed at about 01:00 – 03:00 UT with the digital spectrometers of National Astronomical Observatories of China (NAOC). Also many fiber bursts superposed on the continuum bursts were detected in the frequency range of 2.6 – 3.8 GHz during the time interval. After data processing, some parameters of the fibers such as frequency drift rate, duration, bandwidth, and relative bandwidth were determined. The mean value of the frequency drift was in the range of 42.3 – 87.4 MHz s⁻¹ (negative). A theoretical interpretation for the fibers was presented based upon a model of the velocity of Alfvén solitons. In this model, the source of the fiber emission was considered as the ducting of the solitons within the magnetic-mirror loop. Then the magnetic field strength of the fiber source was estimated to be about 130 ≤ B₀ ≤ 270 G. Also a comparison of the magnetic field estimation was made with another model of whistler group velocity.     

Using the Evolution of Coronal Dimming Regions to Probe the Global Magnetic Field Topology

We demonstrate that study of the evolving magnetic nature of coronal dimming regions can be used to probe the large-scale magnetic structure involved in the eruption of a coronal mass ejection (CME). We analyse the intensity evolution of coronal dimming regions using 195 Å data from the Extreme ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO). We measure the magnetic flux, using data from the SOHO/Michelson Doppler Imager (MDI), in the regions that seem most likely to be related to plasma removal. Then, we compare these magnetic flux measurements to the flux in the associated magnetic cloud (MC). Here, we present our analysis of the well-studied event on 12 May 1997 that took place just after solar minimum in a simple magnetic configuration. We present a synthesis of results already published and propose that driven “interchange reconnection” between the expanding CME structure with ‘`open’' field lines of the northern coronal hole region led to the asymmetric temporal and spatial evolution of the two main dimming regions, associated with this event. As a result of this reconnection process, we find the southern-most dimming region to be the principal foot-point of the MC. The magnetic flux from this dimming region and that of the MC are found to be in close agreement within the same order of magnitude, 10²¹ Mx.     

Observation and Research of the Transits of Extrasolar Planets

In order to make more accurate estimates of the physical parameters of extrasolar planets, the observation and research on the phenomena of transits of the 7 known stars with the planetary systems TrES-1, TrES-3, XO-2, WASP-1, WASP-2, WASP-3 and HAT-P-7 are carried out with the 1-m reflecting telescope at Shandong University Weihai Astronomical Observatory/Weihai Municipal Astronomical Observatory. The fundamental conditions of the observation and data processing are introduced, and the transit light curves as well as the parameters of some planets derived from them are given. At the same time, when the results are summarized and analyzed, the prospects for the more in-depth and detailed researches which will be further carried out are also described.     

Flows,flares, and formation of umbrae and light bridges in BBSO region No. 1167

We present high-resolution observations of the large active region BBSO No. 1167 (Boulder No. 5060) which cast new light on the structure of sunspot regions. We obtained excellent data, highlighted by videomagnetograms (VMG) obtained with our 65-cm telescope, which give unprecedented spatial resolution, about 0.5' for much of two 11-hr periods. This permitted us to see details of the field evolution and flows in the AR. The H filtergrams and D3 filtergrams permit study of these magnetic changes compared to spots and chromospheric structure.The region was a huge but simple active region (CMP July 2, 1988) in which we observed rapid flux emergence for several days. Because the new flux generally matched the old, there were few large flares. However, there were 14 flares on June 28 and 29, mostly in two sites. The first site was a spot which already existed when the active region appeared on the east limb. This site showed little change of magnetic structure during our observing period. The second site is an area disturbed by new flux emergence, which included a spot which formed and disappeared in two days, and a rapidly moving p spot. Flares ocurring at one site almost always produced footpoints at the other. The delay between flash phases of the same flare at the two sites ranges from 40 to 160 s.The magnetograms show complex fine structure, with some closely interwined regions of opposite polarity. In a region of new flux emergence, positive (leading polarity) flux flows along elongated channels immersed in the negative flux. Moving magnetic features occur around all of the spots.We point out other interesting aspects of this large region: (1) While there is extensive penumbra around the main umbrae, there is also significant penumbra apparently unrelated to any spot. These unusual penumbrae are either due to flux returning to the surface, flux left behind by the moving umbra, or associated with pores that appear and disappear. (2) We observed umbrae to move faster than the accompanying penumbrae, and concluded that penumbrae are not a simple extension of the umbra. (3) We found that combining spots of the same polarity do not completely merge, but are always separated by a thin light bridge. This means that the emerging flux loops are discrete entities.     

分块DPCM与5/3整数小波变换结合的天文图像无损压缩

针对海量的天文图像数据与有限的存储空间和带宽资源之间矛盾日益突出这一问题,提出一种无损压缩方法,首先将超大天文图像分块,再使用差分脉冲编码调制和5/3整数小波变换,最后使用霍夫曼算法编码。对该方法的原理和具体实现做了详细的分析与介绍,通过实验验证该方法比天文中常用的tar、PKZip、WinZip、WinRar软件在压缩比上分别提高了30%、29%、26%、2%,压缩速度远大于WinZip和WinRar;且该算法实现简单,适合硬件实现和利于并行处理。     

日冕物质抛射及其伴生的射电辐射观测特征

统计分析了太阳活动周下降段(2003～2005年)发生的76个共生CME的射电爆发事件.射电爆发资料来自国家天文台和Culgoora的微波和米波频谱仪.在76个事件中有50个快速CME和26个慢速CME.从中发现,快速CME和慢速CME的产率分别随着太阳活动周的降低而下降和上升,这可能说明CME的产率与太阳活动周中日冕磁结构的位形和位置变化有关.同时也发现,射电爆发的类型和寿命有一个变化规律,即随着频率的降低射电爆发的寿命变长,此特征支持了伴生CME的Ⅱ型爆发统一模型的思想.另外还发现在厘米一分米波范围,CME开始前后,容易发生射电Ⅲ型爆发或快速精细结构.这说明射电辐射的精细结构可能是CME的前兆现象或CME早期发展阶段由于磁重联引发的低日冕小尺度磁扰动的结果.     

分离式靶标摄影测量在LAMOST中的应用

为了获取LAMOST焦面板上光纤的零位位置,提出了一种基于分离式标准靶标的高精度摄影测量方法。首先,根据Tsai摄像机标定参数模型介绍了CCD相机的标定原理。然后介绍了用光重心算法求取靶标发光点像面坐标及通过球面三角公式计算靶标发光点物面坐标。接着,利用最小二乘法导出了含标定参数的方程组。最后,介绍了标准靶标的放置方法以及提高光纤位置测量精度的靶标取法。实验结果表明:CCD相机的标定残差平均值为8.8μm;标定残差的标准差为5.3μm。测量方法简单易行,通过仔细分析,找出了残差偏大的原因,对后续进一步测量实验有重要指导意义。