Fifty Gravitational Wave Events Illustrated
Over fifty
gravitational wave
events have now been detected.
These events mark the distant, violent collisions of
two black holes,
a black hole and a neutron star, or
two neutron stars.
Most of the
50 events were detected in 2019 by the
LIGO gravitational wave detectors in the
USA and the
VIRGO detector in
Europe.
In the featured illustration summarizing the masses of the first
50 events, blue dots indicate higher-mass
black holes while orange dots denote lower-mass
neutron stars.
Astrophysicists are
currently uncertain, though, about the
nature of events marked in
white involving masses that appear to be in the middle --
between two and five solar masses.
The night sky in optical light
is dominated by nearby and bright planets and stars that have been known since the dawn of humanity.
In contrast, the
sky in gravitational waves
is dominated by distant and dark
black holes
that have only been known about for less than five years.
This contrast is enlightening -- understanding the
gravitational wave
sky is already reshaping humanity's knowledge
not only of
star birth and death across the universe, but
properties of the universe itself.