  The exponential Papapetrou metric induced by scalar field conforms to
observational data not worse than the vacuum Schwarzschild solution. Here, we
analyze the origin of this metric as a peculiar space-time within a wide class
of scalar and antiscalar solutions of the Einstein equations parameterized by
scalar charge. Generalizing the three families of static solutions obtained by
Fisher (1948), Janis, Newman & Winicour (1968), and Xanthopoulos & Zannias
(1989), we prove that all three reduce to the same exponential metric provided
that scalar charge is equal to central mass, thereby suggesting the universal
character of such background scalar field.
