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J. L. R. Saba (Lockheed Martin ATC at GSFC), E. B. Zamkoff (Stanford U. at GSFC), H. E. Mason (Cambridge U.), C. D. Pike (Rutherford Appleton Lab.), J. D. Moses (NRL), J. F. Covington (Lockheed Martin ATC)
As part of an ongoing study of X-ray/EUV bright points (XBPs) in synoptic data from the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SoHO), we consider six CDS XBP detections for which there are concurrent high-cadence, high-spatial-resolution magnetogram data from the SoHO Michelson Doppler Imager (MDI). All six cases occurred at solar minimum or in the early rise phase of solar cycle 23 (Jul 1996 - Jan 1998). They sample a factor of 10 range in size of XBPs as detected by CDS in an Fe XVI coronal emission line, with peak formation temperature of about 2.5 MK. MDI data are available for over 1.5 hr leading up to each CDS observation, and for at least 0.4 hr after; this allows a detailed study of the magnetic field evolution under the XBP site, including detection of flux emergence or cancellation. EIT data are used to monitor the evolution and persistence of these XBPs in the corona before and after the CDS detections.
The nature of the jointly observed XBPs is investigated, in particular the relationship of the plasma parameters and size found with CDS, and the timescales for coronal evolution inferred from EIT, to the character of the underlying magnetic field and its changes as observed with MDI.
This work was supported by the SOI/MDI project at Stanford and LMSAL (grant NAG5-3077). HEM and CDP acknowledge the financial support of PPARC.