Observations of Solar Corona at the Mexico Total Solar Eclipse of July 11, 1991

1991年7月11日的日食是本世纪最重要的日食之一，因为它的日全食持续时间最长。日本日食考察队由国家天文台(6人)、京都大学(3人)和日本水文系(2人)三个研究所组成。前两个研究所得到了蒙布苏国际科学研究基金的这笔赠款的支持。来自国家阿斯特龙的三支队伍。，京都大学。还有九头蛇。出发吧。在UABCS(南下加利福尼亚州自治大学)校园观察，以及来自National Astr的一个团队。Obs.，位于山顶。波波卡托。UABCS的天空条件很好，看起来也很好。在第二次接触之前天气很好，但在山上有一层薄薄的卷云掠过太阳。Popocatetle.仪器，获得的数据的一般特征，…(1)内冕精细结构的观测在FeX6374A、FeXIV5303A、CaXV5694A、Halpha线和6100A连续体的照射下，获得了高分辨率的内冕图像。6374环的结构被发现比任何其他已发表的10^6K日冕环都要精细。发射线图像分别代表了1×10^6K(FeX)、2×10^6K(FeXIV)、3.5×10~(0.6)K(CAXV)和1×10~(4)K(HI)的精细结构，连续谱图像显示了电子柱密度分布。(2)日冕冷物质的观测日冕图像是用HeI10830A、Fe5303A线和10000连续体拍摄的。在紫光(波长3760-4060)和红外(波长10745-10835)的波长范围内也进行了光谱观测，以获得日冕的详细物理条件，特别是其较冷的部分。观测到的日冕射线白光日冕图像研究了日冕射线的宽度变化规律。(4)太阳F日冕的偏振观测在5325A、5965A、7200A、8015A四个波长测量了F日冕的偏振，以研究行星际尘埃颗粒到达太阳的距离。在一定假设条件下，得到了外晕的二维偏振分布图。它显示出与日冕流光共入射的高极化区域。较少

The 11-July-1991 Eclipse was one of the most important eclipse in this century because of its longest duration of totality. The purpose of this research project was to observe the solar corona and to study its physical condition by using this rare oppoetunity.Japanese Eclipse Expedition consists of three institutes, i. e. National Astronomical Observatory (6persons), Kyoto university (3persons), and Hydrographic Department of Japan (2persons). The former two institutes were supported by this Grant under The Monbusho International Scientific Research. Three teams from Nationl Astron. Obs., Kyoto Univ. and Hydro. Depart. observed at the Campus of UABCS (Universidad Autonoma de Baja California Sur), and one team from National Astr. Obs., on the top of Mt. Popocateptle. The sky condition was perfect and the seeing condition was good at UABCS. It was fine before the 2nd contact, but a thin cirrus ran over the sun at Mt. Popocatepetle.The instrumentation, general features of obtained data, a … More nd the results of a preliminary analysis are briefly summarized below.(1) Observation of Fine Structures in the Inner CoronaHigh resolution pictures of the inner corona were obtained in the lights of FeX6374A, FeXIV5303A, CaXV5694A, Halpha lines and 6100A continuum. The 6374 loop structures are found to be finer than any other 10^6K coronal loops which have ever been published. The emission-line images represent the fine structures of 1x10^6K (FeX), 2x10^6K (FeXIV), 3.5xl0^6K (CAXV) and 1x10^4 (HI) respectively, and the continuum images show the electron column density distribution. The detailed cottiparison of thein enables us to study the temperature-density structures of various types of coronal fine structures.(2) Observation of the Cool Material in the CoronaThe coronal images were taken in the light of HeI10830A, Fe5303A linese and 10000 continuum. Spectrographic observations were also made in the wavelength region of violet (lambda lambda3760-4060) and infrared (lambda lambda10745-10835)to obtain the detailed physical condition of the corona, especially of its cool part. The data obtained does not show any distinct cool structures other than ordinary prominences.(3) Observation of the Coronal RaysWhite light coronal pictures were observed to study the width-variations of the coronal rays. It is found that most of the rays expand lineally with distance with the rate of 20-50 arcsec per solar radius.(4) Polarization Observation of the Solar F-CoronaPolarization of F-corona was measured in four wavelengths, i. e., 5325A, 5965A, 7200A, 8015A to study how far interplanetary dust grains reach to sun. With some assumptions, the map of two dimensional polarization distribution of the outer corona was obtained. It shows high polarization regions co-incident with coronal streamers. Less