  On August 14, 2019, the LIGO/Virgo collaboration observed a compact object
with mass $\sim 2.59_{-0.09}^{+0.08}~M_{\odot}$, as a component of a system
where the main companion was a black hole with mass $\sim 23~M_{\odot}$. A
scientific debate initiated concerning the identification of the low mass
component, as it falls into the neutron star - black hole mass gap. The
understanding of the nature of GW190814 event will offer rich information
concerning open issues, the speed of sound and the possible phase transition
into other degrees of freedom. In the present work, we made an effort to probe
the nuclear equation of state along with the GW190814 event. Firstly, we
examine possible constraints on the nuclear equation of state inferred from the
consideration that the low mass companion is a slow or rapidly rotating neutron
star. In this case, the role of the upper bounds on the speed of sound is
revealed, in connection with the dense nuclear matter properties. Secondly, we
systematically study the tidal deformability of a possible high mass candidate
existing as an individual star or as a component one in a binary neutron star
system. As the tidal deformability and radius are quantities very sensitive on
the neutron star equation of state, they are excellent counters on dense matter
properties. We conjecture that similar isolated neutron stars or systems may
exist in the Universe and their possible future observation will shed light on
the maximum neutron star mass problem.
