Anyone can make beautiful, creative images of the Sun using data from orbiting solar observatories thanks to the open data policies and software from Nasa and Esa.
Solar Dynamics Observatory
Nasa launched the SDO as part of its Living With a Star program. Beyond the pure science goals of understanding how the Sun works, learning how it interacts with our own planet makes life on Earth safer. Space weather can disrupt satellite communications, cause blackouts on the ground, and expose frequent fliers to higher levels of radiation.
A Viewer for the Sun
From its geocynchronous orbit around the Earth, the SDO captures a 16 megapixel picture of the Sun every 10 seconds. Every day it sends over a terabyte of data back to Nasa’s data centers. Scientists created a system, called Helioviewer, to help them quickly and easily find the data they need in the rapidly-expanding archives. (You can read more about the Helioviewer project in this arXiv preprint: 0906.1582)
Fortunately, they made Helioviewer an open web application that lets anyone view and download the latest images from the SDO as well as five other solar observatories. You can layer images taken at various wavelengths from infrared through the ultraviolet. And you can animate a series of images to create your own movie of the Sun’s roiling surface.
For my project I went through the various images taken by the Atmospheric Imaging Assembly camera’s 10 filters to see what aspect of the Sun were most prominent. The long infrared wavelengths, for example, show the granular nature of the Sun’s photosphere. The shorter wavelengths I chose, from 171 to 304 nanometers, show the corona and flaring regions where the Sun’s magnetic fields send loops of plasma flying above the surface.
Photoshopping the Sun
The Helioviewer site displays the images in color, but the original files are all in black-and-white. Photoshop lets you colorize each image and layer them one on top of the other. You can be creative by adjusting the hue, saturation, and brightness of each layer to make a combined picture that looks very different from the one the scientists create. (Of course, you destroy the scientific value in the process.) Some selective contrast adjustments using Photoshop’s Curves and Layer Mask tools bring out more of the details which I touched up further in Lightroom.
The final image is a colorful display of the plasma flowing from the Sun’s surface along with the looping plasma flows created as the Sun’s magnetic field rises out of the surface and plunges back in.