No abstract

Analysis of bright features in 3840 ~ and Hc~ shows that for every Ellerman bomb (Hcc--0.9 ~) there is a cospatial brightening in the 3840 ]~ network. We give properties of these bright points in both wavelengths as well as describe: (1) the appearance, and subsequent separation, of new elements in the 3840 A network and (2) the direct transition from a 3840 ~_ bright point to a new sunspot.

Nine coronal emission lines iepresenting five stages of Fe ionization and one stage of Ni were observed in an enhanced coronal region. The data from these observations are presented along with a density model of the enhanced region obtained from the Fe xui and Ni xv emission line ratios as a function of position angle. The electron densities obtained from Fe xIn lines range from Ne ~ 108 to 109 cm -3, and are slightly lower for Nixv line data. Estimates of the variation of temperature over the enhanced region are inferred from the observed line intensities.

The apparent angles of more than 5(100 quiet region spicules situated at various position anglcs around the Sun's limb have been measured on off-band Ha filtergrams taken during the years 1972-1975. The counts were made exclusively in projection on the disk, within 5-25 ~ of the limb. The tcndency of the average spicule to lean towards or away from the pole is small at most, and at no latitudc exceeds 8". The spread in angles is 30-35 ~

Studies of narrow-band interference filters have shown that two mechanisms exist that cause drift to shorter wavelengths. One is dependent on the thermal history of the filter, and the other depends on the radiation history. The present paper presents experimental results on thermal effects; and it is shown that by a proper bake cycle, ZnS-cryolite filters are stable for years if stored at less than 38 degrees C.