Article | Published:

A Theory of Chromospheric Flares


IT has been established from observation that chromospheric flares are closely associated with sunspots, and that the probability of a flare occurring near a spot ncreases with the size of the latter. The probability is higher when the group is increasing its size than when it is stationary, and it is also higher for magnetically complex βγ and γ-groups than for the simpler α- and β-type groups1. The flares themselves are short-lived phenomena, of mean life about thirty minutes, and are quite localized. It is generally accepted that they show no velocity either in height or across the surface of the sun.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Giovanelli, R. G., Astrophys. J., 89, 555 (1939).

  2. 2

    Chapman, S., Mon. Not. Roy. Ast. Soc., 103, 117 (1943).

  3. 3

    Chapman, S., and Cowling, T. G., "The Mathematical Theory of Non-Uniform Gases", 327 (Cambridge University Press, 1939).

  4. 4

    Cillié, G. G., and Menzel, D. H., Harvard College Observatory Circular 410 (1935).

  5. 5

    Cowling, T. G., Proc. Roy. Soc., 183, 453 (1945).

  6. 6

    Observatory, 66, 230 (1946).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.