For 2022's Black Hole's Week,
NASA wanted to create
a data-driven visualization
of a new database of black holess
that have been observed co-orbiting
and feeding upon their stellar companions.
Tabulated data was provided by
Dr Jeremy Schnittman, which
represented many geometric characteristics
of these black hole systems
like the black hole mass,
the star mass,
the space between them,
and their shared orbital period.
Inspired by Dr Dan Fabrycky’s
Kepler exoplanet orrery,
NASA’s Scientific Visualization Studio
set out to create an orrery of
Dr Schnittman’s 22 black hole systems.
By applying the database attributes
to simple geometry,
and by inferring other characteristics
through physical equations and
informed estimates, they were able
to use advanced Hollywood
visual effects tools to bring
each black hole system to life.
Arranging them in an
optimal shape proved difficult,
with early attempts including a 3D spiral
and even clockwork gadgetry.
But the most decipherable layout
proved to be a series of
concentric rings,
with the largest black hole system,
GRS 1915, at the center.
When communicating with data,
it is often more important to
make something understandable
than it is to make it photographically real.
In reality, all of the black hole
event horizon dots at the center
of each accretion disk would be
smaller than a single image pixel,
but for this sequence they are
sized proportionally to their mass
to make it clear that they are indeed
black holes.
Their minuscule sizes were also
the reason no gravitational lensing
is apparent. Orbit lines were added later
to illustrate the sometimes surprising
gravitational influence each of these
massive objects has on its companion.
The gravitational warping of each star
and the differential rotation speed
of each accretion disk was mathematically derived
from the source data. Each accretion disk
was comprised of 2000 textured particles.
It took almost 3 weeks running across the
studio’s 100 render farm machines to generate
the final videos of the orrery and each
black hole system in close-up,
generating 27 thousand 4k final image frames.
There are likely many more black holes
with companion stars yet to be observed,
and we look forward to seeing this dataset
and visualization grow and evolve over time.