2019MNRAS.490.4194H

Recently, there have been several studies on the evolution of binary systems using historical data that are treated as facts in the chain of argument. This paper discusses six case studies of modern dwarf novae with suggested historical counterparts from the historical point of view, as well as the derived consequences for the physics of close binary systems (the dwarf novae Z Cam and AT Cnc, the nebula in M22, and the possible Nova 101, Nova 483 and Nova 1437). I consider the historical Far Eastern reports and, after a careful re-reading of the text, map the given information on to the sky. In some cases, the positions given in modern lists of classical nova-guest star pairs turn out to be wrong, or they have to be considered highly approximate: the historical position should, in most cases, be transformed into areas of the celestial sphere and not into point coordinates. Based on the correct information, I consider the consequences concerning the evolution of close binary systems. The result is that none of the cases of cataclysmic variables suggested to have a historical counterpart can be (fully) supported. Because the identification of the historical record of observation with the cataclysmic variables known today turns out to be always uncertain, a potential historical observation alone cannot be relied on to draw conclusions on the evolution of binaries. Evolution scenarios should be derived from astrophysical observations and modelling only.