GRAVITATIONAL WAVES from galaxy NGC 4993

August 17, 2017 was a historic day for astronomy; in fact, for the first time the optical counterpart of a gravitational wave source was found, which turned out to be a KILONOVA exploded in the galaxy NGC 4993, 130 million light years distant, visible in the constellation of Hydra. GRAVITATIONAL WAVES are deformations and ripples of space-time generated by the sudden and violent movement of large masses, such as the explosions of Supernovae, Hypernovae and Kilonovae.
In particular, when 2 neutron stars collide, part of their mass is converted into energy (E = MC2), giving rise to a strong impulse of gravitational waves that have been detected by LIGO interferometers (in the USA) and VIRGO in Europe (Italy) . Only 2 seconds later, the observatories for the gamma rays INTEGRAL (ESA) and FERMI (NASA), have identified a GAMMA-RAY BURST coming from the same area of the sky. Subsequently all the great optical telescopes were pointed in the same vast area, looking for the optical counterpart of the Gravitational Waves and Gamma rays event. Dozens and dozens of galaxies were analyzed in a short time and an explosion of Kilonova was detected in the NGC 4993 Galaxy. The KILONOVAE are violent explosions resulting from the collision and merger of neutron stars in a binary system. These are fairly rare events, theorized for a long time and for the first time observed. The NEUTRON STARS, whose fusion gave rise to the kilonova, are collapsed stars, deriving from the explosion in Supernova of red giants above the 9 solar masses: when the fuel is missing the star collapses on itself and violently implodes compressing the matter in the nucleus, in such a way as to neutralize the electrons with the protons, while the outer layers are thrown into space giving rise to the explosion of Supernova. A very small collapsed star is formed, of only neutrons, of some solar masses in only 30 Km of diameter. As seen in the galaxy NGC 4993, the neutron stars forming part of a binary system can merge and give rise to a kilonova. In a short time the observed kilonova has become from very blue to very red, due to the expelled material, consisting of heavy chemical elements deriving from stellar nucleosynthesis: Cesius, Tellurio, Gold, Platinum, Selenium, Barium, etc.
It is very probable that the kilonovae give rise to a further compression of the core with a final collapse in a black star-mass hole, that is to say collapsed stars of a dozen solar masses compressed in a few hundred meters and with escape speed superior to light.
The event of Gravitational Waves has been classified with the acronym GW170817 (Gravitational Wave of 17 August 2017). The correspondent Gamma-Ray Burst has been classified with the acronym GRB 170817A (Gamma Ray Burst of 17 August 2017).
ΔΩ

Data : ESO, ESA, NASA.

SOUNDTRACK :
Immediate Music _ FATAL VISION
Immediate Music _ HOW TO CONTROL THE DREAM
Charlie Clouser _ CONVOY

[orlandinabellini]

Comprensibilissimo anche in scientifico perché ben documentato....le immagini di fantasia spiegano bene le enormi energie in gioco .... Buono