Open AccessThe proper motion of sunspots umbra in the rising phase of Cycle 24
Author(s) -
Kamila Permata,
Dhani Herdiwijaya
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1523/1/012016
Subject(s) - differential rotation , sunspot , physics , sidereal time , rotation (mathematics) , solar rotation , differential equation , astrophysics , magnetic field , solar physics , geometry , mathematics , stars , quantum mechanics
The differential rotation is the difference in the rate of rotation of each latitude in the Sun indicating that the Sun is not a solid body. The differential rotation is the result of the interaction between rotation and convection and causes dynamo circulation that affects the cycle of solar activity. In this research, we measured the coordinates of 304 sunspots umbra as tracer in the rising phase of the Solar Cycle 24 to obtain the differential rotation equation. Coordinates of sunspots were measured using AIA images at a wavelength of 4500 Å from SDO (Solar Dynamic Observatory) with JHelioviewer software. The areas of sunspots were measured using HMI (Helioseismic Magnetic Imager) images with ImageJ software. From the measurement, we derived the differential rotation equation and the relation of sidereal rotation and area of sunspots umbra. The differential rotation equation obtained in this research is ω(B) = (14.27 ± 0.01) - (0.78 ± 0.10) sin 2 B (°/day) . There is a difference between the differential rotation equation of the northern and southern hemispheres that indicates the asymmetry between different hemispheres. We got the sidereal rotation of sunspots with area 15 MH.