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Session 80 - Solar Corona and Transition Region.
Oral session, Thursday, June 13
The White Light Coronagraph aboard Spartan 201-03 spacecraft observed the corona on 8, 9 and 10 of September 1995, at a height of 1.5-6.0 R_ødot fromSun center. In conjunction, the ground-based HAO K-coronameter (Mark-III) observed the corona at a height of 1.15-2.1 R_ødot while the space-based Soft X-ray Telescope (SXT) on Yohkoh observed the inner corona at a height of 0-1.5 R_ødot.
In this paper we explore the physical and morphological characteristics of the large-scale coronal structures such as polar coronal rays and high latitude streamers as seen in white-light and relate these structures to observations in soft X-ray (3-45 Åemissions to estimate their temperatures. Past and persent analysis shows that polar rays can be characterized by two temperature classes depending upon the observed properties of the forbidden lines of FeX and FeXIV and soft x-rays. Cool rays are a dominant feature of the polar corona during the quiescent phase of the solar cycle. The hot rays when present form a small subset of the array of rays seen in white-light. Hot rays seem to emerge from the boundary of the polar coronal hole (polar crown filament belt). The location of the cool rays on the other hand can be anywhere inside the coronal hole. We find the emission-line temperature to be high (local maxima, 40-60% higher) in the high latitude coronal streamers with enhanced white-light emission and associated with new cycle high-latitude magnetic fields separated from the old cycle polar field of opposite polarity.
Program listing for Thursday