counter-glown.

1852 E. J. Sabine tr. A. von Humboldt Cosmos III. ii. 416 The brightness of the Zodiacal Light did not appear to me to increase sensibly with the elevation of the observer's station, but rather to depend principally..on greater or less degrees of luminous intensity in the phænomenon itself. I even remarked, when in the Pacific, a counter-glow, like that of sunset.

1888 C. A. Young Text-bk. Gen. Astron. 347 There is said to be in it [sc. the zodiacal light] at the point exactly opposite to the sun a patch a few degrees in diameter of slightly brighter luminosity, called the ‘Gegenschein’ or ‘counter-glow’.

1956 Nature 18 Feb. 308/2 Attention was also directed..to recent studies on the counterglow by workers in the U.S.S.R.

1967 New Scientist 9 Mar. 464/2 There is a slight increase in brightness at the point in the sky diametrically opposite to the Sun, and this is known as the gegenschein or counterglow.