A New Black Hole in Discovered in Earth’s Galactic Neighborhood

After posts about giant hornets which can dissolve flesh with their stings,  a huge asteroid passing by Earth, and a mass cemetery in New York City, it is hard to know what to write about next… Thankfully, astronomers are way ahead of me!  This week featured the announcement that scientists have discovered a black hole “right in our backyard.”

Fortunately, what counts as our backyard to astronomers is not really our backyard by any quotidian definition.  Located in the southern constellation Telescopium, the newfound black hole is 1,000 light-years away: although it is the closest black hole to Earth discovered thus far, it is still 9.5 quadrillion kilometers away (5.88 quadrillion miles).  We probably won’t blunder into it by accident when we sneak downstairs for a midnight snack.

Black holes, as you know, are deformed patches of spacetime where gravity is so strong that all proximate matter and electronic radiation (like light) are pulled into the gravity well.  Black holes form when exceedingly massive stars collapse at the end of their life cycle:  they become more massive as additional matter accretes into them.   For example the supermassive black hole at the center of the galaxy is believed to have the mass of 431 million suns!

The black hole’s orbit in the star system is marked in red

The newly discovered Telescopium black hole is nothing like that though.  Scientists estimate its mass to be mere 4 to 5 times that of the sun.  Astronomers were able to discover the object only because the other two stars in its solar system (which they were studying in order to better understand binary stars) were not orbiting each other in a comprehensible fashion.  Some massive third party was implicated…yet nothing was visible. Ergo, a black hole.  There are believed to be hundreds of millions or even billions of these invisible horrifying objects in our galaxy alone, but they are nearly impossible to find unless there are nearby objects for them to interact with (yet which have not been slurped down into the ravenous maw).

I wonder where the actual closest black hole to Earth is located? Maybe we don’t really want to find out…

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This strange object which resembles a bottle gourd is actually a depiction of the largest yellow star known to science. HR5171A is located 11,700 light years from Earth in the heart of Centaurus (a southern constellation).  Actually the image above is two stars: HR5171A is part of a binary system and its companion star is so close that the topology of the hypergiant is affected. The smaller companion is not visible.  To quote Universe Today, “what we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant.” It is uncanny how the giant star looks like a 1930s cartoon character’s head!  The combined system has a total mass 39 times that of our own sun, but their volume is vastly larger—nearly 1,300 times greater that that of the sun (and the luminosity of the star is a million times greater).  Although HR5171A is much less large than the true giants (like the astonishing Eta Carinae which has 120 solar masses), its ultimate fate is still not happy.  Yellow hypergiant stars are passing through a transitional phase on the way to going supernova (so enjoy it now, while you can).