A luminous atmospheric phenomenon appearing as streamers or bands of light sometimes visible in the night sky in northern or southern regions of the earth It is thought to be caused by charged particles from the sun entering the earth's magnetic field and stimulating molecules in the atmosphere, The dawn
Of or pertaining to the magnetic pole, or to the point to which the magnetic needle is directed, tube, containing a polarizing apparatus, turning on an axis parallel to that of the earth, and indicating the hour of the day on an hour circle, by being turned toward the plane of maximum polarization of the light of the sky, which is always 90› from the sun, the aurora borealis or australis, noun_ A great circle two of whose points are each a quadrant from a given point_ it is the polar of the given point, Given a trihedral; to each face from the vertex erect a perpendicular ray on the same side as the third edge; the trihedral they form is the polar of the given one