Black hole is closest to Earth, among the smallest ever discovered
by Laura Arenschield, The Ohio State University
Scientists have discovered one of the smallest black holes on record—and the closest one to Earth found to date.
https://phys.org/news/2021-04-black-hole-closest-earth-smallest.html?
This explains why captain_spalding can’t find h’ sunglasses.
Witty Rejoinder said:
Black hole is closest to Earth, among the smallest ever discovered
by Laura Arenschield, The Ohio State University
Scientists have discovered one of the smallest black holes on record—and the closest one to Earth found to date.https://phys.org/news/2021-04-black-hole-closest-earth-smallest.html?
> ‘The Unicorn,’ in part because it is, so far, one of a kind, and in part because it was found in the constellation Monoceros
> The Unicorn is about three times the mass of our sun—tiny for a black hole.
So it could be a neutron star? Checking here: https://news.psu.edu/story/623786/2020/06/23/research/black-hole-or-neutron-star “the heaviest known neutron star is no more than 2.5 times the mass of our sun, or 2.5 solar masses, and the lightest known black hole is about 5 solar masses … scientists have announced the discovery of an object of 2.6 solar masses, We don’t know if this object is the heaviest known neutron star, or the lightest known black hole, but either way it breaks a record”.
> This black hole is 1,500 light years away from Earth, still inside the Milky Way galaxy.
There are other black holes within the Milky Way. Let’s look up SS 433. https://en.wikipedia.org/wiki/SS_433 “SS 433 is one of the most exotic star systems observed. It is an eclipsing X-ray binary system, with the primary most likely a black hole, or possibly a neutron star. The spectrum of the secondary companion star suggests that it is a late A-type star. SS 433 is the first discovered microquasar. It is at the centre of the supernova remnant W50. … Estimates for its mass range from 3 to 30 solar masses. … Distance 18,000±700 ly”. So SS 433 has a similar mass and distance to this new one, withing observational limits.
> The black hole appears to be a companion to a red giant star. …. That star had been well-documented by telescope systems including KELT, run out of Ohio State; ASAS, the precursor to ASAS-SN, which is now run out of Ohio State, and TESS, a NASA satellite that searches for planets outside our solar system. Data about it had been widely available but hadn’t yet been analyzed in this way.
> causing the light from that star to change in intensity and appearance at various points around the orbit. Something was tugging at the red giant and changing its shape.
That’s a new method, or one too old for me to know. Why hadn’t I heard about this before? It’s got to be an old method, used for analysing contact binaries. Right?
The big question I suppose is: If it is a black hole, how did it get there? Or to put it another way, how did a close binary survive a supernova?
SCIENCE said:
This explains why captain_spalding can’t find h’ sunglasses.
Just around the corner at 1500 ly but perhaps too compact to image
The Doubly Warped World of Binary Black Holes
https://www.youtube.com/watch?v=rQcKIN9vj3U
A pair of orbiting black holes millions of times the Sun’s mass perform a hypnotic dance in this NASA visualization. The movie traces how the black holes distort and redirect light emanating from the maelstrom of hot gas – called an accretion disk – that surrounds each one.
Read more: http://www.nasa.gov/feature/goddard/2…
Viewed from near the orbital plane, each accretion disk takes on a characteristic warped look. But as one passes in front of the other, the gravity of the foreground black hole transforms its partner into a rapidly changing sequence of arcs. These distortions play out as light from the accretion disks navigates the tangled fabric of space and time near the black holes.
The simulated binary contains two supermassive black holes, a larger one with 200 million solar masses and a smaller companion weighing half as much. Astronomers think this kind of black hole system is one in which both members could maintain a long-lived accretion disk.
The disks have different colors, red and blue, to make it easier to track the light sources, but the choice also reflects reality. Gas orbiting lower-mass black holes experiences stronger effects that produce higher temperatures. For these masses, both accretion disks would actually emit most of their light in the UV, with the blue disk reaching a slightly higher temperature.
Visualizations like this help scientists picture the fascinating consequences of extreme gravity’s funhouse mirror.
Seen nearly edgewise, the accretion disks look noticeably brighter on one side. Gravitational distortion alters the paths of light coming from different parts of the disks, producing the warped image. The rapid motion of gas near the black hole modifies the disk’s luminosity through a phenomenon called Doppler boosting an effect of Einstein’s relativity theory that brightens the side rotating toward the viewer and dims the side spinning away.
The movie also shows a more subtle phenomenon called relativistic aberration. The black holes appear smaller as they approach the viewer and larger when moving away.
These effects disappear when viewing the system from above, but new features emerge. Both black holes produce small images of their partners that circle around them each orbit. Looking closely, it’s clear that these images are actually edge-on views. To produce them, light from the black holes must be redirected by 90 degrees, which means we’re observing the black holes from two different perspectives – face on and edge on – at the same time. Zooming into each black hole reveals multiple, increasingly distorted images of its partner.
The visualization, created by Goddard astrophysicist Jeremy Schnittman, involved computing the path taken by light rays from the accretion disks as they made their way through the warped space-time around the black holes. On a modern desktop computer, the calculations needed to make the movie frames would have taken about a decade. So Schnittman teamed up with Goddard data scientist Brian P. Powell to use the Discover supercomputer at the NASA Center for Climate Simulation. Using just 2% of Discover’s 129,000 processors, these computations took about a day.
Astronomers expect that, one day, they’ll be able to detect gravitational waves – ripples in space-time – produced when two supermassive black holes in a system much like the one Schnittman depicted spiral together and merge.
Music credit: “Gravitational Field” from Orbit. Written and produced by Lars Leonhard. Used with permission.
Video credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell
Scott Wiessinger (USRA): Producer
Jeremy Schnittman (NASA/GSFC): Lead Visualizer
Brian Powell (NASA/GSFC): Visualizer
Francis Reddy (University of Maryland College Park): Science Writer