  The mass-luminosity (M-L), mass-radius (M-R) and mass-effective temperature
($M-T_{eff}$) diagrams for a subset of galactic nearby main-sequence stars with
masses and radii accurate to $\leq 3\%$ and luminosities accurate to $\leq
30\%$ (268 stars) has led to a putative discovery. Four distinct mass domains
have been identified, which we have tentatively associated with low,
intermediate, high, and very high mass main-sequence stars, but which
nevertheless are clearly separated by three distinct break points at 1.05, 2.4,
and 7$M_{\odot}$ within the mass range studied of $0.38-32M_{\odot}$. Further,
a revised mass-luminosity relation (MLR) is found based on linear fits for each
of the mass domains identified. The revised, mass-domain based MLRs, which are
classical ($L \propto M^{\alpha}$), are shown to be preferable to a single
linear, quadratic or cubic equation representing as an alternative MLR. Stellar
radius evolution within the main-sequence for stars with $M>1M_{\odot}$ is
clearly evident on the M-R diagram, but it is not the clear on the $M-T_{eff}$
diagram based on published temperatures. Effective temperatures can be
calculated directly using the well-known Stephan-Boltzmann law by employing the
accurately known values of M and R with the newly defined MLRs. With the
calculated temperatures, stellar temperature evolution within the main-sequence
for stars with $M>1M_{\odot}$ is clearly visible on the $M-T_{eff}$ diagram.
Our study asserts that it is now possible to compute the effective temperature
of a main-sequence star with an accuracy of $\sim 6\%$, as long as its observed
radius error is adequately small (<1%) and its observed mass error is
reasonably small (<6%).
