It is the star we know most about but still not nearly enough. Life on Earth depends on it and that is why we need to study it further.
It is known that the Sun is around 110 times bigger in diameter than the Earth and 330 000 more massive. This is important, as it shows that even the smallest event on the surface of the Sun can mean disaster for our planet.
For example on 01.09.1859 the largest recorded geomagnetic storm occurred. From August 28 until September 2, 1859, numerous sunspots and solar flares were observed on the Sun, the largest flare occurring on September 1. This is referred to as the Solar storm of 1859 or the Carrington Event. Telegraph wires in both the United States and Europe experienced induced electromagnetic field, in some cases even shocking telegraph operators and causing fires. Thankfully researches show evidence that events of similar intensity recur at an average rate of approximately once per 500 years. It is considered that if such event occurs now it will interrupt almost every electric devices on Earth including communication satellites in orbit.
So far humanity has learned that the frequency of geomagnetic storms is directly related to the eleven year sunspot cycle. Here a graph of three consequent cycles is shown.
As we see from the graph during 1980, 1991 and 2001 the Sun was at its cycle`s maximum and thus we can conclude that 2012 was an year of a maximum. Although we can predict the year, and even the month of a maximum, we cannot predict it`s height or the exact moments the flares will occur.
Now we know that during 2023 the next solar maximum will occur and we need to be prepared. One thing that gives us information (although we still do not understand it completely) is the number and location of the solar spots.
On the graph below the moment in time and the latitude of the spots is shown. As we see, they have a similar cycle as the solar activity and they are formed closer to the equator as time goes.
As seen on the next graph, sun flares follow a similar pattern.
It is obvious that there are more factors regarding the solar activity, than the solar cycle alone. Probably there are longer cycles interfering with the eleven-year one or even interaction with close stars, but these are factors, that we cannot take into account in real time, even if we prove them right.
The sunspot represents an area on the Sun`s surface, where the magnetic field lines are twisted in such a way that they stop the convection of plasma. This way the material that is already on the surface of the Sun is not replaced with hotter one, but has time to cool down and thus become fainter. These phenomena are more dynamic than it seemed from the previous graphs so on this one a shorter period of time is represented.
As you can see, we need more detailed information to cope with possible flares.
Thankfully, there are few things, which we can measure in real time. One of them is the Solar Irradiance or the power of electromagnetic radiation per unit area incident on the surface. As seen from the next graph this has connection with the solar cycle and flares.
All the connections and values shown so far are either mean values from measurements done by several people or an averaged graph made by computer using data from a satellite (admittedly solar radiation can be measured and plotted in real time, but such small changes in the flux do not help us make predictions).
The most dynamic feature of the Sun, that we can study, is the solar wind. Our project`s goal is to visualize its characteristics in the most intuitive and easy-to-work-with way. This way, we might contribute to a step forward in analysis and understanding of the multidimensional data and establishing a better model for space weather forecast.
The solar wind is characterized by the magnitude and of the magnetic field, the temperature of the particles, their velocity, and their density. Our team works with data gathered from the ACE satellite and we are going to work towards real time visualizations on the platform, but we will first visualize some bits of old data.
The first graph represents the speed, density and magnetic induction of the solar wind, while the second one shows the energy of the electrons and protons as a function of time.
As we can see, even on a 7-day time scale, parameters change dynamically.
Hopefully, when we gain full understanding of the governing processes, we will be able to predict all major phenomena occurring on the Sun.
Written by Canimir and Nikola