  Centaurs, distinguished by their volatile-rich compositions, play a pivotal
role in understanding the formation and evolution of the early solar system, as
they represent remnants of the primordial material that populated the outer
regions. Stellar occultations offer a means to investigate their physical
properties, including shape, rotational state, or the potential presence of
satellites and rings.
  This work aims to conduct a detailed study of the centaur (54598) Bienor
through stellar occultations and rotational light curves from photometric data
collected during recent years.
  We successfully predicted three stellar occultations by Bienor, which were
observed from Japan, Eastern Europe, and the USA. In addition, we organized
observational campaigns from Spain to obtain rotational light curves. At the
same time, we develop software to generate synthetic light curves from
three-dimensional shape models, enabling us to validate the outcomes through
computer simulations.
  We resolve Bienor's projected ellipse for December 26, 2022, determine a
prograde sense of rotation, and confirm an asymmetric rotational light curve.
We also retrieve the axes of its triaxial ellipsoid shape as a = (127 $\pm$ 5)
km, b = (55 $\pm$ 4) km, and c = (45 $\pm$ 4) km. Moreover, we refine the
rotation period to 9.1736 $\pm$ 0.0002 hours and determine a geometric albedo
of (6.5 $\pm$ 0.5) %, higher than previously determined by other methods.
Finally, by comparing our findings with previous results and simulated
rotational light curves, we analyze whether an irregular or contact-binary
shape, the presence of an additional element such as a satellite, or
significant albedo variations on Bienor's surface, may be present.
