共查询到17条相似文献,搜索用时 62 毫秒
1.
给出1997年3月9日日全食时所作的日冕偏振CCD观测资料的处理结果,包括太阳赤道东西和两极等十二个方向的中冕(1.6 ̄3.2R⊙)绝对亮度分布和偏振度分布。 相似文献
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给出1997年3月9日日全食时所作的日冕偏振CCD观测资料的处理结果,包括太阳赤道东西和两极等十二个方向的中冕(1.6-3.2R)绝对亮度分布和偏振度分布。 相似文献
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目前太阳活动处于极小期,太阳表面的活动区磁场处于相对不活动状态。但暗条和冕洞等活动形式仍有存在。特别是极区冕洞,其性质仍有许多疑团不被人所知。例如磁场对冕洞的影响。在中低太阳纬度,冕洞出现在大块的磁场单极区。然而在高纬区情况如何呢?冕洞在极区经常存在(极区冕洞),但并不总是存在。我们曾看到美国高山天文台(HAO)于1973观测的一幅日全食照片,其南极有明显的极区冕洞,而北极区存在有纤细而美丽的冕羽。我国1968年和1980年两次日全食所观测的资料只有中内冕(R⊙—1.5R⊙以内),R⊙大于1.5R⊙的外日冕平时还只有在空间才能得到。1997年3月9日日全食是本世纪我国国土上观测日冕的良好机会,但条件限制我们不能携带专门用于日全食观测的大型设备,本文提出了一种用普通摄像机拍摄日冕像而再进行图像采集处理的方法,以获得R⊙大于等于2范围的日冕观测方案。另外在日全食观测前后,需要用同一台摄像机在同盘磁带上对黑暗进行拍摄以备暗场处理之用。再用同台摄像机和GG11滤光片在同盘磁带上对均匀天空进行拍摄以作黄光,白光平场背景之用。根据不同研究的需要,在资料处理时,应作相应的绝对定标,大气消光及位移的改正。 相似文献
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目前太阳活动处于极小期,太阳表面的活动区磁场处于相对不活动状态,但暗条和冕洞等活动形式仍有存在,特别是极区冕洞,其性质仍多疑团不被人所知,例旭磁场对冕洞的影响,在中低太阳纬度,冕洞出现大块的磁场单极区,然而在高纬区情况如何呢?冕洞在极区经常存在(极区冕洞),但并不总是存在。我们曾看到美国高山天文台(HAO)于1973观测一幅日全食照片,其南极有明显的极区冕洞,而北极区存在有纤细而美丽的冕羽,我国1 相似文献
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1997年3月9日的日全食是本世纪中国可见的最后一次日全食.对这次日食概况和中国、特别是漠河地区见食的情况作一介绍.这次观测结果基本上与预报一致,文中所列各表供观测者处理资料时参考. 相似文献
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1997年3月9日日全食8.6mm波段射电观测资料的分析表明:8.6mm波段射电太阳的半径为1.012R,总流量为2540sfu(1sfu=10-22W/m2Hz),日面平均亮温度为9632K,径向亮温度分布,在日面光学边缘内侧0.936-0.992R处,存在临边增亮,平均增亮幅度相对于日面中心为9.7%. 相似文献
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1997年3月9日日全食8.6mm波段射电观测资料的分析表明,8.6mm波段射电太阳的半径为1.012R,总流量为2540sfu(1sfu=10^-22W/m^2Hz),日面平均亮温度为9632K,径向亮温度分布,在日面光学边缘内侧0.936-0.992R处,存在临边增亮,平均增亮幅度相对于日面中心为9.7%。 相似文献
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利用简单的视频图像采集系统 ,对 1 997年 3月 9日用PanasonicNV -S880EN型摄像机拍摄的黑龙江漠河日全食黄光 (加GG1 1滤光片 )和白光日冕观测资料进行计算处理 ,得到大于 1 .5R⊙ 的太阳活动低年外日冕结构及其相对强度分布。 相似文献
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Solar diameter measurements have been made nearly continuously through different techniques for more than three centuries.
They were obtained mainly with ground-based instruments except for some recent estimates deduced from space observations.
One of the main problems in such space data analysis is that, up to now, it has been difficult to obtain an absolute value
owing to the absence of an internally calibrated system. Eclipse observations provide a unique opportunity to give an absolute
angular scale to the measurements, leading to an absolute value of the solar diameter. However, the problem is complicated
by the Moon limb, which presents asphericity because of the mountains. We present a determination of the solar diameter derived
from the total solar eclipse observation in Turkey and Egypt on 29 March 2006. We found that the solar radius carried back
to 1 AU was 959.22±0.04 arcsec at the time of the observations. The inspection of the compiled 19 modern eclipses data, with
solar activity, shows that the radius changes are nonhomologous, an effect that may explain the discrepancies found in ground-based
measurements and implies the role of the shallow subsurface layers (leptocline) of the Sun. 相似文献
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Nelson L. Reginald Joseph M. Davila O. C. St. Cyr Douglas M. Rabin Madhulika Guhathakurta Donald M. Hassler Hadi Gashut 《Solar physics》2011,270(1):235-251
An experiment was conducted in conjunction with the total solar eclipse on 29 March 2006 in Libya to measure both the electron
temperature and its flow speed simultaneously at multiple locations in the low solar corona by measuring the visible K-coronal
spectrum. Coronal model spectra incorporating the effects of electron temperature and its flow speed were matched with the
measured K-coronal spectra to interpret the observations. Results show electron temperatures of (1.10±0.05) MK, (0.70±0.08) MK,
and (0.98±0.12) MK, at 1.1 R
⊙ from Sun center in the solar north, east and west, respectively, and (0.93±0.12) MK, at 1.2 R
⊙ from Sun center in the solar west. The corresponding outflow speeds obtained from the spectral fit are (103±92) km s−1, (0+10) km s−1, (0+10) km s−1, and (0+10) km s−1. Since the observations were taken only at 1.1 R
⊙ and 1.2 R
⊙ from Sun center, these speeds, consistent with zero outflow, are in agreement with expectations and provide additional confirmation
that the spectral fitting method is working. The electron temperature at 1.1 R
⊙ from Sun center is larger at the north (polar region) than the east and west (equatorial region). 相似文献
14.
We performed high resolution spectroscopy of the solar corona during the total solar eclipse of 22 July 2009 in two emission
lines: the green line at 5303 ? due to Fe xiv and the red line at 6374 ? due to Fe x, simultaneously from Anji (latitude 30°28.1′ N; longitude 119°35.4′ E; elevation 890 m), China. A two-mirror coelostat with
100 cm focal length lens produced a 9.2 mm image of the Sun. The spectrograph using 140 cm focal length lens in Littrow mode
and a grating with 600 lines per millimeter blazed at 2 μm provided a dispersion of 30 m? and 43 m? per pixel in the fourth
order around the green line and third order around the red line, respectively. Two Peltier cooled 1k × 1k CCD cameras, with
a pixel size of 13 μm square and 14-bit readout at 10 MHz operated in frame transfer mode, were used to obtain the time sequence
spectra in two emission lines simultaneously. The duration of totality was 341 s, but we could get spectra for 270 s after
a trial exposure at an interval of 5 s. We report here on the detection of intensity, velocity, and line width oscillations
with periodicity in the range of 25 – 50 s. These oscillations can be interpreted in terms of the presence of fast magnetoacoustic
waves or torsional Alfvén waves. The intensity ratios of green to red emission lines indicate the temperature of the corona
to be 1.65 MK in the equatorial region and 1.40 MK in the polar region, relatively higher than the expected temperature during
the low activity period. The width variation of the emission lines in different coronal structures suggests different physical
conditions in different structures. 相似文献
15.
George L. Withbroe 《Solar physics》2009,257(1):71-81
The daily images and magnetograms acquired by MDI are a rich source of information about the contributions of different types
of solar regions to variations in the total solar irradiance (TSI). These data have been used to determine the temporal variation
of the MDI irradiance, the mean intensity of the solar disk in the continuum at 676.8 nm. The short-term (days to weeks) variations
of the MDI irradiance and TSI are in excellent agreement with rms differences of 0.011%. This indicates that MDI irradiance
is an excellent proxy for short-term variations of TSI from the competing irradiance contributions of regions causing irradiance
increases, such as plages and bright network, and regions causing irradiance decreases, such as sunspots. However, the long-term
or solar cycle variation of the MDI proxy and TSI differ over the 11-year period studied. The results indicate that the primary
sources of the long-term (several months or more) variations in TSI are regions with magnetic fields between about 80 and
600 G. The results also suggest that the difference in the long-term variations of the MDI proxy and TSI is due to a component
of TSI associated with sectors of the solar spectrum where the contrast in intensity between plages and the quiet Sun is enhanced
(e.g., the UV) compared to the MDI proxy. This is evidence that the long-term variation of TSI is due primarily to solar cycle
variations of the irradiance from these portions of solar spectrum, a finding consistent with modeling calculations indicating
that approximately 60% of the change in TSI between solar minimum and maximum is produced by the UV part of the spectrum shortward
of 400 nm (Solanki and Krivova, Space Sci. Rev. 125, 53, 2006). 相似文献
16.
Gravity Anomaly During the Mohe Total Solar Eclipse and New Constraint on Gravitational Shielding Parameter 总被引:1,自引:0,他引:1
By using a high-precision LaCoste-Romberg gravimeter, continuous and precise measurements were carried out during the March
9, 1997 total solar eclipse in Mohe region in Northeast China. The gravity variations were digitally recorded during the total
solar eclipse so as to investigate the possible anomaly of the Sun and the Moon's gravitational fields on the Earth. After
the careful processing and analysis of the observed data, no significant anomaly during the very solar eclipse was found.
However, there are two ‘gravity anomaly valleys’ with near symmetrical decrease of about 6 ∼ 7 μg at the first contact and the last contact. This is the anomaly phenomenon observed and reported for the first time in the
literature. This paper is intended to explain the observed anomaly by conducting the tilt experiment due to the thermal stress
and temperature change in the solar eclipse. A new constraint limit on gravitational shielding is thus obtained. Some analysis
and discussions are presented although further studies and research are highly needed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
During the total solar eclipse at Akademgorodok, Siberia, Russia, on 1 August 2008, we imaged the flash spectrum with a slitless
spectrograph. We have spectroscopically determined the duration of totality, the epoch of the second and third contacts and
the duration of the flash spectrum. Here we compare the 2008 flash spectra with those that we similarly obtained from the
total solar eclipse of 29 March 2006, at Kastellorizo, Greece. Any changes of the intensity of the coronal emission lines,
in particularly those of Fe x and Fe xiv, could give us valuable information about the temperature of the corona. The results show that the ionization state of the
corona, as manifested especially by the Fe xiv emission line, was much weaker during the 2008 eclipse, indicating that following the long, inactive period during the solar
minimum, there was a drop in the overall temperature of the solar corona. 相似文献