The Magnetic Field Effects

of Stellar Bodies

A report by:

Comm. R.M. Wey

COSR: SFS-SFC

The magnetic fields of a stellar body can heat the surrounding surface of its corona to many millions of degrees Celsius, causing these areas to glow. It is this dynamo effect that ‘drives’ the stellar phenomenon observed.

It is only the ‘main sequence’ stars [those which still burn hydrogen as their primary fuel source] that concern us here, as they are the primary source for life on class M worlds.

Though it should be noted that, as a stellar body uses up its source of hydrogen, magnetic activity increases as it begins its evolution into a red giant [which varies greatly in amplitude and duration, depending on the age and mass of the star before its conversion].

Now observations' of ‘sunspots’ have been recorded for more than two thousand years, and have established the existence of a cycle which lasts eleven years [in which the stellar bodies magnetic poles reverse] and thus is repeated

every twenty-two [allowing for the poles to return to their original state].

Now a sunspot is a region of relatively cooler gases which are formed whenever magnetic fields emerge from a stellar bodies' core. This, in turn, suppresses the normal flow of ‘fused’ matter from reaching the stars' surface.

The dynamo of a stellar body is believed to be in the convection zone [the outer two hundred thousand kilometers] where churning hot gases are drawn up from the stars' interior.

There are two essential components that make such a phenomenon possible: The first, are the convective cyclones[Coriolis forces that cause large convective cells to flow in clockwise and counterclockwise directions at the northern and southern hemispheres]. The second, is the stellar body's non-uniform rotation [for Sol: a period of twenty-five days at the equator, twenty-eight at latitude of forty-five degrees, etc.].

As the cycle progresses, the magnetic activity increases as well. This also increases the brightness of the stellar body [as noted by the increase in the emissions of violet calcium].

However, the activity begins to slow as a star begins to age. For a relatively young star, this is a period of ten to fifteen days, for older ones this period can substantially increase.

This is also true regarding peak magnetic activity; When a star is young, the ‘darkspots’ [regions of intense magnetic activity with field strength of several thousand gauss (the earth’s by comparison, is only point five of one gauss)] outnumber the plages [extremely bright regions on the stars' surface].

However, when a star begins to age, these correlation’s shift so that, as the stars rotates more slowly, and the magnetic activity slows, radiance peaks only at sunspot maximum.

As its angular momentum declines, the dynamo effect becomes stable; thus, there are fewer sunspots. However, some never reach an equilibrium until they are nearing the end of their lives as main sequence stars, only to then subsequently evolve into red giants.

As observations require many decades to establish patterns of activity recognizable as such, further research into this area of study will be conducted and updates provided, as they become available.