Sun's Rate Research Articles

Analysis of Sunspot Time Series During the Ascending Phase of Solar Cycle 24 Using the Wavelet Transform

The sunspots are widely used to measure the rotational rate of solar surface. We are interested in analysis of the temporal evaluation of the short-term period present in sunspot time series (i.e. sunspot number and area) during the ascending phase of Solar Cycle 24. For the better understanding of variation in solar activity originated at different layers of the solar atmosphere with respect to sunspot cycles, we study the phase relation between sunspot numbers and sunspot areas using cross correlation analysis techniques based on extended wavelet based approaches such as continuous wavelet transform, cross-wavelet transform, and wavelet coherence. In this study we found the short-term periodicity “27 days-rotational rate of Sun” for current solar cycle 24 (January2008-May2013), which suggested that the Solar Cycle24 has minimum solar activity. We have also investigated the correlation between both parameters and identify the unusual conditions in space weather.

Luminosity and solar corona related to rate of rotation

Recently, observations and theory have been combined to relate sunspot activity, luminosity, and even X ray corona structure with the sun's rate of rotation. According to W. Waller of the Harvard‐Smithsonian Center for Astrophysics, who reported recently on a workshop on magnetic activity in lab‐type stars, a new theory is emerging which tries to link rotation to stellar activity. It is based on the model of a magnetic dynamo, whereby swirling motions within the stellar core induce a large‐scale magnetic field. Because some parts of the star rotate faster than others, the magnetic field becomes frayed and twisted at its extremities.

Sun Compensation by Bees

In both their navigation and dance communication, bees are able to compensate for the sun's movement. When foragers are prevented from seeing the sun for 2 hours, they compensate by extrapolation, using the sun's rate of movement when last observed. These and other data suggest a time-averaging processing strategy in honey bee orientation.

Optimal Control of Sun Tracking Solar Concentrators

Using the disciplines of Modern Control Theory, an optimal tracking control for a point focusing solar concentrator is derived. By converting the tracking problem into a regulator problem with a sun rate input a very low pointing error is achieved. A representative example with a corresponding computer simulation is presented.