  In this work, we study spherically symmetric vacuum solutions in 1-parameter
New General Relativity (NGR), a specific theory in teleparallel gravity which
is constructed from the three possible quadratic scalars obtained from torsion
with arbitrary coefficients satisfying the requirements for the absence of
ghosts. In this class of modified theories of gravity, the observable effects
of gravity result from the torsion rather than the curvature of the spacetime.
Unlike in GR, where the fundamental quantity is the metric from which the
Levi-Civita connection is derived, in teleparallel theories of gravity the
fundamental variable is the tetrad, from which one constructs the metric and
the teleparallel connection. We consider the most general tetrad for spherical
symmetry and we derive the corresponding field equations. Under adequate
assumptions, we find three different branches of vacuum solutions and discuss
their associated phenomenology. In particular, we analyze the photon sphere,
the classical tests of GR such as the light deflection, the Shapiro delay, and
the perihelion shift, and also the Komar mass, while providing a detailed
comparison with their Schwarzschild spacetime counterparts. Finally, we analyze
how the observational imprints from accretion disks and shadows are affected in
comparison with their GR counterparts, and conclude that the free parameters of
the model might induce additional attractive or repulsive effects to the
propagation of photons, depending on their values.
