  After the discovery of rings around the largest known Centaur object, (10199)
Chariklo, we carried out observation campaigns of stellar occultations produced
by the second-largest known Centaur object, (2060) Chiron, to better
characterize its physical properties and presence of material on its
surroundings. We predicted and successfully observed two stellar occultations
by Chiron. These observations were used to constrain its size and shape by
fitting elliptical limbs with equivalent surface radii in agreement with
radiometric measurements. Constraints on the (2060) Chiron shape are reported
for the first time. Assuming an equivalent radius of R$_{equiv}$ =
105$^{+6}_{-7}$ km, we obtained a semi-major axis of a = 126 $\pm$ 22 km.
Considering Chiron's true rotational light curve amplitude and assuming it has
a Jacobi equilibrium shape, we were able to derive a 3D shape with a semi-axis
of a = 126 $\pm$ 22 km, b = 109 $\pm$ 19 km, and c = 68 $\pm$ 13 km, implying
in a volume-equivalent radius of R$_{vol}$ = 98 $\pm$ 17 km, implying a density
of 1119 $\pm$ 4 kg m$^{-3}$. We determined the physical properties of the 2011
secondary events around Chiron, which may then be directly compared with those
of Chariklo rings, as the same method was used. Data obtained from SAAO in 2018
do not show unambiguous evidence of the proposed rings, mainly due to the large
sampling time. Meanwhile, we discarded the possible presence of a permanent
ring similar to (10199) Chariklo's C1R in optical depth and extension. Using
the first multi-chord stellar occultation by (2060) Chiron and considering it
to have a Jacobi equilibrium shape, we derived its 3D shape. New observations
of a stellar occultation by (2060) Chiron are needed to further investigate the
material's properties around Chiron, such as the occultation predicted for
September 10, 2023.
