Solar differential rotation in the period 1964-2016 determined by the Kanzelhohe data set

0482493 - ASÚ 2018 RIV FR eng J - Journal Article
Beljan, I.P. - Jurdana-Šepić, R. - Brajša, R. - Sudar, D. - Ruždjak, D. - Hržina, D. - Pötzi, W. - Hanslmeier, A. - Veronig, A. - Skokić, Ivica - Wöhl, H.
Solar differential rotation in the period 1964-2016 determined by the Kanzelhohe data set.
Astronomy & Astrophysics. Roč. 606, October (2017), A72/1-A72/10. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA MŠMT(CZ) 7E13003
EU Projects: European Commission(XE) 312495 - SOLARNET
Institutional support: RVO:67985815
Keywords : Sun * photosphere * rotation
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.565, year: 2017

Kanzelhohe Observatory for Solar and Environmental Research (KSO) provides daily multispectral synoptic observations of the Sun using several telescopes. In this work we made use of sunspot drawings and full disk white light CCD images. The main aim of this work is to determine the solar differential rotation by tracing sunspot groups during the period 1964-2016, using the KSO sunspot drawings and white light images. We also compare the differential rotation parameters derived in this paper from the KSO with those collected fromf other data sets and present an investigation of the north - south rotational asymmetry. The interactive procedure of position determination is fairly accurate but time consuming. In the case of the much faster automatic procedure for position determination, we found the rLSQ method for calculating rotational velocities to be more reliable than the DS method. For the test data from 2014, the rLSQ method gives a relative standard error for the differential rotation parameter B that is three times smaller than the corresponding relative standard error derived for the DS method. The best fit solar differential rotation profile for the whole time period is omega(b) = (14.47 +/- 0.01) (2.66 +/- 0.10) sin(2) b (deg/day) for the DS method and omega(b) = (14.50 +/- 0.01) (2.87 +/- 0.12) sin(2) b (deg/day) for the rLSQ method. A barely noticeable north - south asymmetry is observed for the whole time period 1964-2016 in the present paper. Rotation profiles, using different data sets, presented by other authors for the same time periods and the same tracer types, are in good agreement with our results.


Permanent Link: http://hdl.handle.net/11104/0277925