PREDNASAJUCI / LECTURER :

Vojtech Rušin

(1) Astronomical Institute, Slovak Academy of Sciences,
059 60 Tatranská Lomnica

NAZOV / TITLE :

Morphological study of 2013 November 3 solar corona as observed in La Lope park (Gabon)

ABSTRAKT / ABSTRACT :

Analysis the structure and dynamics of the white-light corona (WLC) has been observed in Gabon
during the annular-total (“hybrid”) solar eclipse of 2013 November 3 (total across Africa,
including our location). The eclipse occurred between the double maxima (2012 and 2014) of cycle
24, which ranked among the weakest in many decades. Even though the cycle amplitude, in terms of
sunspot number, was very low, the WLC had a typical cycle maximum shape with many helmet streamers
or long rays uniformly distributed around the solar limb and filled with many loops, arcades or
thin rays. This distribution yields the flattening index of 0.04, appropriate for the phase of the
cycle. Two coronal mass ejections (CMEs) were detected. Their positions are rather atypical (far
away from active regions): the first one was located at position angle (PA) 11o and at a height of
2.83 solar radii (its lower edge was located at 2.13 solar radii) and  its occurrence was connected
with a small dynamic prominence. The second was located on the opposite part of the solar pole at
PA 192o with its base height at 3.26 solar radii as result an internal dynamics in the low lying
prominence. The projected speed of the northern CME was approximately 140 km s-1; that of the
second CME was about 120 km s-1 (these plane-of-sky velocities were derived using SOHO/LASCO C2
observations). Finally, a brief comparison of the WL and EUV coronas is given.