AO 0235+164 : a red BL Lac object.

Abstract

AO 0235 + 164, an inverted-spectrum radio source identified with a faint red stellar object, is shown to be an optical/radio variable. This plus its featureless optical spectrum lead us to classify AO 0235+164 as an object similar to BL Lacertae. Subject headings: BL Lacertae objects - radio sources