The Sun has been relatively quiet of late, but that doesn’t mean that there isn’t anything to look at on our local star. NASA’s Solar Dynamics Observatory (SDO) provided this side-by-side rendering of the Sun on 10-11 December at two different wavelengths of extreme ultraviolet light to illustrate how solar astronomers can tease out different features of our dynamic companion. SDO’s Advanced Imaging Assembly (AIA) observes the Sun at ten separate wavelengths.
On the left is a red image showing the Sun at the 304 Angstrom wavelength. This captures plasma closer to the Sun’s surface, showing light that is emitted from the chromosphere and transition region. This material is at relatively cool temperatures of 50,000 Kelvin. On the right is the golden Sun at 171 Angstroms, highlighting the Sun’s atmosphere, or corona. This region features towering magnetic arcs of material known as coronal loops. The temperature at this wavelength is twelve times hotter, at 600,000 Kelvin.
Using SDO’s AIA gives researchers the opportunity to study solar temperatures that range from 4,500 Kelvin all the way to 10 million Kelvin, helping them understand how material moves through the solar atmosphere. In addition, SDO uses its Helioseismic and Magnetic Imager (HMI) to study the movement and magnetic properties of the Sun’s surface. If you want to see the complete SDO range, click this.
Image credit: Solar Dynamics Observatory/NASA