October 21, 2003



20031021.190606_mk4

Center =137.79+/-0.73 degrees PA (SE quadrant) (red radial line)
Maximum height = 1.64+/-0.06 Rsun
Width (at 1.20 Rsun) = 19.87+/-0.85 degrees latitude (measured between edges -- vertical dashed lines at inflection points)
Width (at 1.41 Rsun) = 17.32+/-0.61 degrees latitude
Cavity depletion, equatorward (1.20 Rsun) = 0.13+/-0.017 (ratio of red to blue dashed line)
Cavity depletion, equatorward (at 1.41 Rsun) = 0.02+/-0.020 (ratio of red to blue dashed line)
Cavity depletion, poleward (1.20 Rsun) = 0.04+/-0.019 (ratio of green to blue dashed line) Minimum intensity in cavity (1.20 Rsun) = 2.9e-07+/-2.9e-09 (Bsun) (blue dashed lines);
Cavity depletion, poleward (1.41 Rsun) = -0.04+/-0.021 (ratio of green to blue dashed line) Minimum intensity in cavity (1.41 Rsun) = 1.6e-07+/-1.6e-09 (Bsun) (blue dashed lines);
Slope at equatorward cavity edge (1.20 Rsun) = -1.7e-08+/-5.8e-09 (Bsun/degree)
Slope at equatorward cavity edge (1.41 Rsun) = 5.6e-09+/-3.1e-09 (Bsun/degree)
Slope at poleward cavity edge (1.20 Rsun) = -3.8e-09+/-5.8e-09 (Bsun/degree)
Slope at poleward cavity edge (1.41 Rsun) = -6.7e-09+/-3.1e-09 (Bsun/degree)

length lower limit = 5 days visible in white light at limb October 21; -22; -24; -25**; -26 ;

Recurrence =East limb September 25; -27; West limb October 9; -10; East limb October 21; -22; -24; -25**; -26 ; East limb December 12; -14; West limb December 21; -22; -23; -24; -26; -27***;
Evolution comments = Another PCF system, where PCF gets longer and clearer over time. Faintly visible SE Sep 25-27, then SW Oct 9-10, then better visible SE Oct 21-24 and really vis Oct 25-26. No Mk4 Oct 27, and maybe something vis. Oct 28. Associated filament on disk disappears by Oct 29 -- but this is the time of the Halloween storms and all hell has broken loose. around Vis. again on SW limb Nov 7-10 - maybe a partial eruption (EIT) Nov 8. Poss. also recur Nov 20-23.., then prom at East limb Dec 12,14; visible at West limb Dec 21-27 -- getting quite dark and high 26-27 -- but no EIT data after 25 and very limited LASCO data, and no Mk4 data Dec 13, 25, 28:31

Neutral line orientation at the limb =
CME/dimmings association = N/A

Active region association = N/A

Filament/FC association = e.g. prominence at East limb Oct 26; N/A

Other comments: N/A

Filament - only visible in H-alpha or EUV

Necking - bulging neck


Cavity list (e.g. Tables 2 + 3)
Full list of cavity days observed
List of best cavity days (SET 1) observed (e.g. Table 1)
CMEs associated with cavities (e.g. Tables 7 + 8)
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