24 synoptic maps of average magnetic field in 296 prominences measured by the Hanle effect during the ascending phase of solar cycle 21. (arXiv:2007.08219v4 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Bommier_V/0/1/0/all/0/1">V. Bommier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Leroy_J/0/1/0/all/0/1">J.L. Leroy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sahal_Brechot_S/0/1/0/all/0/1">S. Sahal-Brechot</a>
Aims : We present 24 synoptic maps of solar filaments, in which the average
unambiguous magnetic field vectors of 296 prominences were determined with
Pic-du-Midi observations between 1974 and 1982. This was the ascending phase of
cycle 21. Methods : The magnetic field was determined by interpreting the Hanle
effect, which is observed in the ion{He}{i} D$_3$ line. Previous results for
the prominence field polarity and prominence chirality were applied to solve
the fundamental ambiguity. The measurements were averaged in each prominence
for accuracy reasons. Results : The result is twofold. First, alternating field
directions can be observed from one neutral line to the next. Second, a general
field alignment is found along a solar north-south field that is distorted by
the differential rotation effect. The numerical data for the prominences and
their magnetic field coordinates are provided as online material associated
with this paper.
Aims : We present 24 synoptic maps of solar filaments, in which the average
unambiguous magnetic field vectors of 296 prominences were determined with
Pic-du-Midi observations between 1974 and 1982. This was the ascending phase of
cycle 21. Methods : The magnetic field was determined by interpreting the Hanle
effect, which is observed in the ion{He}{i} D$_3$ line. Previous results for
the prominence field polarity and prominence chirality were applied to solve
the fundamental ambiguity. The measurements were averaged in each prominence
for accuracy reasons. Results : The result is twofold. First, alternating field
directions can be observed from one neutral line to the next. Second, a general
field alignment is found along a solar north-south field that is distorted by
the differential rotation effect. The numerical data for the prominences and
their magnetic field coordinates are provided as online material associated
with this paper.
http://arxiv.org/icons/sfx.gif
