  We conduct a systematic examination of the properties of models for
chemically homogeneous, differentially rotating, main-sequence stars of mass
1-2 M_sun. The models were constructed using a code based on a reformulation of
the self-consistent field method of computing the equilibrium stellar structure
for a specified conservative internal rotation law. [abridged] Relative to
nonrotating stars of the same mass, these models all have reduced luminosities
and effective temperatures, and flattened photospheric shapes (i.e., decreased
polar radii) with equatorial radii that can be larger or smaller, depending on
the degree of differential rotation. For a fixed ratio of the axial rotation
rate to the surface equatorial rotation rate, increasingly rapid rotation
generally deepens convective envelopes, shrinks convective cores, and can lead
to the presence of a convective core (envelope) in a 1 M_sun (2 M_sun) model, a
feature that is absent in a nonrotating star of the same mass. The positions of
differentially rotating models for a given mass M in the H-R diagram can be
shifted in such a way as to approximate the nonrotating ZAMS over ranges in
luminosity and effective temperature that correspond to a mass interval between
M and about 0.7 M. We briefly note a few of the implications of these results,
including (i) possible ambiguities arising from similarities between the
properties of rotating and nonrotating models of different masses, (ii) a
reduced radiative luminosity for a young, rapidly rotating Sun, (iii) the
nuclear destruction of lithium and other light metallic species in the layers
beneath an outer convective envelope, and (iv), the excitation of solar-like
oscillations and the operation of a solar-like hydromagnetic dynamo in some
1.5-2 M_sun stars.

Astrophysics