X-ray flare longitude distribution

[hb9tmc]

After 8 years of observation I have the impression that the most powerful (X-ray) flares occur on the eastern/western limb.

Is that just my selective perception, or do flares generally radiate more effectively sideways?


73, Stefan

[justsomeguy]

Since the sun is a sphere turning in space and we are circling it at a different rate, the eastern and western limb are constantly changing in position and thus have no relevance to the sun itself, only the earth's position around the sun. Thus, your implication that "sideways" have some meaning on the sun is, well, not correct.

[lsvalgaard]

Oct 1, 2011 13:32:25 GMT justsomeguy said:

Since the sun is a sphere turning in space and we are circling it at a different rate, the eastern and western limb are constantly changing in position and thus have no relevance to the sun itself, only the earth's position around the sun. Thus, your implication that "sideways" have some meaning on the sun is, well, not correct.

But because of foreshortening a sunspot group can be seen for a longer time near the limbs [even after the group has rotated to the backside, its magnetic field still 'sticks up' for some time, thus there is a greater chance of seeing a flare near the limb.

There is also more sunspots on the Western half of the Sun. The 'why' is left as an exercise

[hb9tmc]

Oct 1, 2011 13:32:25 GMT justsomeguy said:

Since the sun is a sphere turning in space and we are circling it at a different rate, the eastern and western limb are constantly changing in position and thus have no relevance to the sun itself, only the earth's position around the sun. Thus, your implication that "sideways" have some meaning on the sun is, well, not correct.

Yes, that is obvious. I meant if exactly the same flare would appear on E90 and on E0, the E90 one would shine brighter on X-ray than the E0 one.

[hb9tmc]

I just found the answer and more on this topic here:
www.aanda.org/articles/aa/pdf/2003/15/aa2997.pdf