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H. R. Gilbert, J. T. Burkepile, A. J. Hundhausen, J. A. Darnell (HAO/NCAR), F. Bagenal (University of Colorado, Boulder)
Coronal Mass Ejections (CMEs) are often associated with activity in the chromosphere and photosphere. H-alpha observations suggest two different forms of prominence activity. We will label these "active prominences" and "erupting prominences" for purposes of comparison with CMEs. A prominence is defined as being "active" when material moves outward then returns sunward or fades without visibly leaving the Sun's gravitational field. In contrast, an eruptive prominence has material that visibly leaves the Sun, often separating from the main, anchored part of a prominence. The departing material of an eruptive prominence may fade from H-alpha observations as it travels outward, or it may remain visible in H-alpha as it leaves the field of view of the instrument. A study of 54 active and eruptive prominences was conducted using H-alpha, Helium I, and Coronal White Light data from the Mauna Loa Solar Observatory in addition to LASCO C2 and C3 data. 94 eruptive prominences and only 46 studied were associated with the occurrence of a CME in the MKIII or LASCO fields of view. Properties such as heights, velocities, and accelerations of active prominences are compared with those of eruptive prominences. Similarly, properties of prominences associated with the occurrence of a CME are compared with those that had no associated CME. Using the high cadence H-alpha limb data, further emphasis is placed on the acceleration profiles of the eruptive prominences. There is evidence in some events a third order fit (a least-squares fit of a cubic function) to the observed trajectory is superior to a second order fit, implying a changing rather than constant acceleration of the prominence material. Following prominence material from the low corona out to many solar radii may help in determining if a third order fit to any trajectories of CME features is better than the lower order fits.
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