Image of the sun taken from the SOHO satellite. 

 Today we know that  the sun is no more than a star which is near to us. Like it, the stars we call fixed stars are large gaseous spheres, of which 99% is hydrogen and helium. In their centre there is a continuous nuclear reaction, much more powerful than our hydrogen bombs, which maintains its surface at a temperature of thousands of degrees. 

Fixed stars are distributed randomly in the sky making groups we call constellations. Now let's ask some questions:

  Are all the stars the same distance away? Are they all alike? Are the so-called fixed stars really immobile? To be able to answer these questions, click on Fixed stars