A new technique for deriving prominence mass from SOHO/EIT Fe XII (19.5 nanometers) absorption features

It is presently unclear what role prominences play in the initiation and dynamics of coronal mass ejections (CMEs), although erupting prominences are strongly correlated with CMEs. The masses of prominences involved in CMEs are not generally measured, but the accurate determination of such masses may help in assessing the dynamical importance of prominences in CME events. In the technique for deriving prominence mass introduced in the present work, we use observations of coronal radiation in the Fe XII (19.5 nm) spectral line, which is absorbed by prominence material. This new method allows us to consider the effects of both foreground and background radiation in our calculations, and it can be applied to both quiescent and erupting prominences by using two versions of the method, which we label the "spatial-interpolative" version and the "temporal-interpolative" version. When both versions can be applied to the same event, we find that the temporal-interpolative approach yields the more accurate results. We have applied both versions to an erupting prominence observed on 1999 July 12 (this prominence has an associated CME), and we find that the two approaches result in similar mass determinations: (6.0 ± 2.5) × 10¹⁴ g for the temporal-interpolative approach and (7.4 ± 4.6) × 10¹⁴ g for the spatial-interpolative approach.