Here's how boffins can prove Solar System's mysterious 'Planet Nine' is actually a small black hole – wait, what?
- Reference: 1594358050
- News link: https://www.theregister.co.uk/2020/07/10/planet_nine_black_hole/
- Source link:
The observatory, previously known as the Large Synoptic Survey Telescope (LSST), has been under construction in Chile since 2015, and is expected to begin observing the heavens this year. It will be home to a [1]giant telescope that employs a “three-mirror, three-lens optical assembly” to focus light from the night’s sky onto the “world’s largest CCD camera.”
Avi Loeb and Amir Siraj, chairman of the Department of Astronomy and an undergraduate student, respectively, at Harvard University believe the new telescope will be able to determine whether or not Planet Nine, a hypothetical object, is a black hole or not within a year of the instrument becoming operational.
[2]Planet Nine , if it exists, has remained elusive since it was predicted by a pair of astronomers at the California Institute of Technology in 2015. Fruitless searching for the strange body has led some scientists [3][PDF] to believe it’s not visible at all because it may, in fact, be a black hole.
'Planet nine' theory boosted by Kuiper Belt Object with odd orbit [4]READ MORE
Loeb and Siraj have come up with a method to detect Planet Nine if, of course, it really is a black hole estimated to be five to ten solar masses. Their approach is described in a paper expected to appear in The Astrophysical Journal – a pre-print version [5][PDF] is available on arXiv. Their technique involves spotting luminous flares erupting at the outer edge of our Solar System. These bursts will be produced whenever the black hole gobbles up any comets and other stuff that flies too close to the proposed swirling disk of gas and dust.
"In the vicinity of a black hole, small bodies that approach it will melt as a result of heating from the background accretion of gas from the interstellar medium onto the black hole," said Siraj. "Once they melt, the small bodies are subject to tidal disruption by the black hole, followed by accretion from the tidally disrupted body onto the black hole."
In other words, matter flying towards Planet Nine will get pulled apart and swallowed, if it is a black hole. The interaction produces electromagnetic energy that signals to the presence of this invisible void.
"Because black holes are intrinsically dark, the radiation that matter emits on its way to the mouth of the black hole is our only way to illuminate this dark environment," said Loeb.
The new telescope has a wide-field view that can search for these random flashes of light in outer space. "LSST has a wide field of view, covering the entire sky again and again, and searching for transient flares," said Loeb. "Other telescopes are good at pointing at a known target but we do not know exactly where to look for Planet Nine. We only know the broad region in which it may reside," Siraj added. ®
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[1] https://www.lsst.org/about/tel-site
[2] https://www.theregister.com/2016/03/31/planet_nine_theory_boosted_by_kbo_find/
[3] https://arxiv.org/abs/1909.11090
[4] https://www.theregister.com/2016/03/31/planet_nine_theory_boosted_by_kbo_find/
[5] https://arxiv.org/abs/2005.12280
[6] https://whitepapers.theregister.com/
Surely "a black hole estimated to be five to ten solar masses ... at the outer edge of our Solar System" would be detectable by other means than powerful telescopes? The whole Solar System would be orbiting around the thing!
Indeed, but El Reg appears to have misread* the paper that speculates that it might be a black hole. That paper discusses Primordal Black Holes which are very different beast to those formed by collapsing stars and the mass is in the same range as that of the speculated Planet 9.
* I know there's a way to report this, but I can't remember what this is
That was my point - the paper is proposing five Earth masses.
Counter balanced
... By the black hole in the White House
At what mass do you orbit
So, a black hole of five to ten solar masses as planet nine. One has to question the logic here. What is orbiting what? If planet nine is a planet , then it will be in rather "close" orbit to the sun. Otherwise, it cannot be called a planet. But, if it is in the orbital plane with all us other small rocky and gaseous balls, then I'd guess our chances for survival to be zero with a black hole as close as a planet nine.
One has to question, at five to ten solar masses, is a black hole going to orbit this solar system or will this solar system be orbiting that black hole? And then, if we are that close to a black hole, wouldn't any orbital dynamics of this solar system become chaotic? Ah well, we must be close to the event horizon and be in a state of relativistic slowdown. At least we would have plenty of time to ponder the questions of life, the universe and everything(*) when squeezed that close to a black hole.
(*) yes, six times nine and so on...
Re: At what mass do you orbit
As already pointed out above, our astronomical Vulture got the wrong kind of black hole.
Ah, so 5-10 *earth* masses
Totally different beast.
IIRC that's about 1/3 the mass of Jupiter.
And yes, on that scale you would need a telescope to find it.
Putting one of the universes most mysterious objects practically in our back yard. Our own baby black hole.
Exciting times. Something to raise a glass to on a Friday at beer o'clock.
Great just what I need in 2020
First, COVID-19, then a one night stand getting pregnant. And now a black hole. Great.