"Ahad radius" - does it change with direction of travel ?

Didn't Greg Neill write on my screen:

You only have to stand outside on a clear night under
non light-polluted skies to know that the average light
flux differs from place to place in the sky. The Milky
Way has a much higher average illumination per square
degree than, say, directions galactic-poleward.

Ahhaa, but the sphere is a conceptual one, and based on _total_ flux
of the night sky. Its radius is only 0.18 - light year compared to a
30,000 light year distance to the centre of our galaxy. So whether you
are 0.18 light-year out from the sun in a direction _opposite_ to the
galactic core or _toward_ the galactic core, the point of flux
equivalence will be the same.

Check his vanity art--
http://uk.geocities.com/aa_spaceagen...erstellar.html

My other Q, is does the sun radiate _equally_ equatorially as polar?
That could change the dimensions of the Ahad sphere.

Rob