In the binary-driven hypernova (BdHN) scenario, long gamma-ray bursts (GRBs)
originate in a cataclysmic event that occurs in a binary system composed of a
carbon-oxygen (CO) star and a neutron star (NS) companion in close orbit. The
collapse of the CO star generates at its center a newborn NS ($\nu$NS), and a
supernova (SN) explosion. Matter from the ejecta is accreted both onto the
$\nu$NS because of fallback and onto the NS companion, leading to the collapse
of the latter into a black hole (BH). Each of the ingredients of the above
system leads to observable emission episodes in a GRB. In particular, the
$\nu$NS is expected to show up (hereafter $\nu$NS-rise) in the early GRB
emission, nearly contemporary or superimposed to the ultrarelativistic prompt
emission (UPE) phase, but with a different spectral signature. Following the
$\nu$NS-rise, the $\nu$NS powers the afterglow emission by injecting energy
into the expanding ejecta leading to synchrotron radiation. We here show that
the $\nu$NS-rise and the subsequent afterglow emission in both systems, GRB
180720B and GRB 190114C, are powered by the release of rotational energy of a
Maclaurin spheroid, starting from the bifurcation point to the Jacobi ellipsoid
sequence. This implies that the $\nu$NS evolves from a triaxial Jacobi
configuration, prior to the $\nu$NS-rise, into the axially symmetric Maclaurin
configuration observed in the GRB. The triaxial $\nu$NS configuration is
short-lived (less than a second) due to a copious emission of gravitational
waves, before the GRB emission, and it could be in principle detected for
sources located at distances closer than $100$ Mpc. This appears to be a
specific process of emission of gravitational waves in the BdHN I powering long
GRBs.
