In order to study the temporal behavior of fine structure in the solar chromosphere, time-lapse sequences of spectroheliograms have been obtained in the violet emission peak (Kzv) of Ca II 2 3933. Figure 1 shows such a time-lapse sequence taken with the 36 cm image of the McMath Telescope at the Kitt Peak National Observatory*. The spatial resolution approaches one second of arc and the temporal resolution is 45 s/frame for a duration of 1 h and 35 rain. The spectroheliograph bandpass is 0.12 A centered at 0.18 A to the violet of the K 3 line core.
The region in Figure 1 is located at a heliocentric angle of 27 ~ directed toward the north pole. The pictures are printed in negative. Near the center of each frame there is a small sunspot. At the rim of the sunspot there are many emission features about 1500 km in size. The brightness of these emission features is comparable to that of network fragments, i.e. about 3 times the intensity of the quiet background (Liu and Sheeley, 1971).
In viewing a 16 mm movie made from this time sequence of spectroheliograms, some of these emission features are found to move outward from the rim of the sunspot until they are eventually lost in the small plage. A check of the original film shows that these features can be identified unambiguously on every frame. In Figure 1, we have selected 10 frames covering a period of 60 rain to illustrate this outflow. On the frame of 8h47ml I S, the feature indicated by an arrow starts at the lower left rim of the sunspot. By 9h46mll s, the feature has moved about 6000 kin, corresponding to an average transverse velocity of 1.7 km s-1.
Beckers and Schr6ter (1968) have shown that in a sunspot region there are many 'magnetic knots' with field strength of 600 to 1400 Gauss and that the positions of these knots coincide with small regions of strong K232 emissions. Sheeley (1969) has reported that near sunspots bright CN elements, which are intimately associated with magnetic fields (Sheeley, 1971), stream outward at about 1 km s-1. Direct magnetic observations (Vrabec, 1971 ;Harvey, 1971) have confirmed this outward streaming of tiny magnetic elements with field strengths of a few hundred Gauss outside the sunspots. Apparently the streaming of the K2v emission features observed here is the same phenomenon, but occurring at somewhat greater heights in the chromosphere than where the magnetic field is measured. * Sponsored by the National Science Foundation.