Superflare
Since superflares can occur on stars apparently equivalent in every way to the Sun, it is natural to ask if they can occur on the Sun itself. An estimate based on the original Kepler photometric studies suggested a frequency on solar-type stars (early G-type and rotation period more than 10 days) of once every 800 years for an energy of 10 erg and every 5000 years at 10 erg. One-minute sampling provided statistics for less energetic flares and gave a frequency of one flare of energy 10 erg every 5–600 years for a star rotating as slowly as the Sun; this would be rated as X100 on the solar flare scale. This is based on a straightforward comparison of the number of stars studied with the number of flares observed. An extrapolation of the empirical statistics for solar flares to an energy of 10 erg suggests a frequency of one in 10,000 years.
List of solar storms
Solar storms of different types are caused by disturbances on the Sun, most often coronal clouds associated with coronal mass ejections (CMEs) produced by solar flares emanating from active sunspot regions, or, less often, from coronal holes. Solar filaments (solar prominences) may also trigger CMEs, trigger flares, or occur in conjunction with flares, and associated CMEs can be intensified.