Photosphere
Videos
The photosphere is a star's outer shell from which light is radiated. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately 2⁄3, or equivale
Sun's surface in false color
Solar atmosphere: temperature and density. See here for meanings of extra lines in the graph.
Neutron star
Videos
A neutron star is the gravitationally collapsed core of a massive supergiant star. It results from the supernova explosion of a massive star—combined with gravitational collapse—that compresses the co
Photosphere
…to an optical depth of approximately 2⁄3, or equivalently, a depth from which 50% of light will escape without being scattered. Stars, except perhaps neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. The term photosphere…
Image of the Crab Nebula taken by the Hubble Space Telescope. The wind echo of the Crab Pulsar can be seen on the center-right of the image.
Radiation from the rapidly spinning pulsar PSR B1509−58 makes nearby gas emit X-rays (gold) and illuminates the rest of the nebula, here seen in infrared (blue and red).
A computer simulation depicting a neutron star with accretion disk, spewing out X-rays through the magnetic axis
NASA artist's conception of a "starquake", or "stellar quake"