One of the three key features of the Sun when seen in X-rays, the others being active regions and coronal holes. Unlike active regions, coronal bright points are distributed at all latitudes on the solar disk. Bright points have a central core around 10 000 km wide and mostly occur above areas of opposite magnetic polarity on the photosphere; when the regions of opposite polarity encounter each other and cancel out, energy is released that heats the gas above the photosphere to a few million degrees K. Bright points also occur when newly emerged magnetic field reacts with the pre-existing magnetic field in the corona, again with the release of magnetic energy to heat the gas. Coronal bright points have typical lifetimes of a day. They are often referred to as X-ray bright points or EUV bright points, according to the wavelength at which they are observed.