1991年日全食近红外光谱观测结果

RESULTS FROM NEAR INFRARED SPECTRAL OBSERVATION OF 1991 TOTAL SOLAR ECLIPSE

介绍１９９１年７月１１日墨西哥日全食的近红外光谱（１０７１２－１０９７２）观测资料和分析结果．从无缝谱得出的极边缘光球连续谱表面亮度曲线上发现在日面边缘之内２１０ｋｍ处有一强度凹陷，由该曲线拐点定出色球底的温度为４４２５±２６°Ｋ．无缝闪光谱资料显示Ｈｅｌ１０８３０线在边缘外１２００ｋｍ附近发射达极大，其下降段的对数梯度β为０．６３３×１０－８ｃｍ－１，与可见区Ｈｅｌ线相近．此外，东边大日珥的资料显示该日珥的强度很弱，仅为普通日珥强度的２％—５％，具有很大的湍流速度（约３０ｋｍ／ｓｅｃ）和视向蓝移运动（２１０±１５ｋｍ／ｓｅｃ）．由于Ｐγ在光谱上没有显示，所以认为其激发程度很高．

Introduced in this paper are the data and analytical results of infrared spectral observation (10712-10972) of the total solar eclipse of July 11,1991 in Mexico. The surface brightness curve, derived from the continua of extreme limb photosphere of flash spectra, has a dip at about 210km inside the solar disk limb. The temperature at the bottom of the chromosphere, i.e. the inflection point of the surface brightness curve, is about 4425±26°K. The flash spectra show that the HeI 10803 line reaches a maximum of emission at about 1200km beyond the photosphere, and the logarithmic gradient of the decreasing part of its integrated intensity curve is 0.633×10 -8 cm -1 , which is close to of other He lines in optical region. In addition, spectra of the big prominence at east limb indicate that it is a very weak prominence with intensity of 2%-5% of ordinary prominences. This prominence has large turbulent velocity (about 30km/sec) and blueshift velocity along the light of sight (210±15km/sec). We think the prominence is highly excited since there is no trace of P γ in the spectra observed. We did not detect any chromospheric emission of non prominence property.