Small - Scale Eruptive Filaments on the Quiet

We conducted a study of a little known class of eruptive events on the quiet sun. 61 small-scale eruptive filamentary structures were identified in a systematic survey of 32 days of Ha time-lapse films of the quiet sun acquired at Big Bear Solar Observatory. When fully developed, these structures have an average length of 15 arc seconds before eruption. They appear to be the small-scale analog of large-scale eruptive filaments observed against the disk. At the observed rate of 1.9 small-scale eruptive features per field of view per average 7.0 hour day, we estimate the rate of occurrence of these events on the sun to be greater than 600 per 24 hour day. The average duration of the eruptive phase was 26 minutes while the average lifetime from formation through eruption was 70 minutes. A majority of the smallscale filamentary structures were spatially related to cancelling magnetic features in line-ofsight photospheric magnetograms. Similar to large-scale filaments, the small-scale filamentary structures sometimes divided opposite polarity cancelling fragments but often had one or both ends terminating at a cancellation site. Their high numbers appear to reflect the much greater number and mixture of small-scale than large-scale aggregates of opposite polarity magnetic flux on the quiet sun. From their characteristics, evolution and relationship to photospheric magnetic flux, we conclude that the structures described in this study are small-scale eruptive filaments and are a subset of all filaments.