Stellar classification
Videos
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffrac
UGC 5797, an emission-line galaxy where massive bright blue stars are formed
Artist's impression of a Y-dwarf
Image of the carbon star R Sculptoris and its striking spiral structure
Sirius A and B (a white dwarf of type DA2) resolved by Hubble
Sun
Videos
The Sun is the star located at the centre of the Solar System. It is a massive sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surf
Stellar classification
…for subgiants, class V for main-sequence stars, class sd (or VI) for subdwarfs, and class D (or VII) for white dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a surface temperature around 5,800 K. The conventional colour description takes into account only the…
The Sun as viewed through a clear solar filter
The photosphere is structured by convection cells referred to as granules.
The Sun's transition region taken by Hinode's Solar Optical Telescope
During a total solar eclipse the solar corona can be seen with the naked eye.