15 Billion Solar Masses

A few months back I wrote a deep dive on why the discovery of gravitational waves was such a big deal in the field of physics. Effectively, gravitational waves gave us a whole new method for observing the universe, and among other things, allow us to directly observe blackholes rather than simply attempt to infer their existence as we had done previously.

Now another observatory, the Very Long Baseline Array (VBLA), which in a concept similar to LIGO is a group of ten telescopes spread across over 8,000 km from Mauna Kea, Hawaii to St. Croix, Virgin Islands which are all controlled from Socorro, New Mexico. This massive collection of 25m antennas has managed to observe two supermassive black holes orbiting one another.

In the past couple decades it has become clear that at the center of (nearly?) every galaxy is a super massive blackhole. We knew that galaxies collide and merge with one another, and with this new technology it would be possible to watch how two of these gigantic behemoths interact with one another.

For Taylor, the discovery is the result of more than 20 years of work and an incredible feat given the precision required to pull off these measurements. At roughly 750 million light years from Earth, the galaxy named 0402+379 and the supermassive black holes within it, are incredibly far away; but are also at the perfect distance from Earth and each other to be observed.
Bansal says these supermassive black holes have a combined mass of 15 billion times that of our sun, or 15 billion solar masses. The unbelievable size of these black holes means their orbital period is around 24,000 years, so while the team has been observing them for over a decade, they've yet to see even the slightest curvature in their orbit.

There's even a false color photo of the two blackholes relative to one another. While obviously not something that can be represented in a visible sense, it is so cool that we are able to determine the mass and position of these objects so massive they absorb any energy radiating near its surface. Despite it being physically impossible to look at, we are observing them with the truly unbelievable precision. Researcher Roger Romani gives the mind bending analogy:

"If you imagine a snail on the recently-discovered Earth-like planet orbiting Proxima Centauri - 4.243 light years away - moving at 1 cm a second, that's the angular motion we're resolving here," said Roger W. Romani, professor of physics at Stanford University and member of the research team.

Math is amazing. Also, quick reminder that since these guys are about 750 million light years away, the whole scene actually occurred around 750 million years ago.