Stephen Hawking, James Hartle and Alexei Starobinski are no longer with us, and neither is John Wheeler, but other great pioneers of black hole theory are! Like Roger Penrose and Kip Thorne. It is often said that it was the work of Robert Oppenheimer that laid the foundations of the theory of black holes, but we can trace it back to the work of Subrahmanyan Chandrasekhar who first understood that beyond a certain mass, a star having exhausted its thermonuclear fuel must gravitationally collapse giving what we now call a black hole.
Today, the fascination with these compact stars that distort time and space, which still contain many mysteries and perhaps are sometimes gateways to parallel universes, has been fueled in particular by Interstellar and the image of the black hole M87* revealed by the collaboration ofEvent horizon telescope. Many people therefore undoubtedly want to take part in one of the greatest adventures undertaken by the noosphere of the geochemist Vladimir Vernadsky and the geologist and paleontologist Pierre Teilhard de Chardin, the collective spirit, so to speak, of A wise manand helps unravel the mysteries of black holes. But they probably also think that this is a possibility reserved for astrophysicists.
However, as Arthur Clarke had prophesied in the 1960s, during a broadcast of BBC, advances in telecommunications and computing have not only helped this noosphere develop a planetary consciousness and culture, but the 30-plus year growth of the Internet also allows anyone with a computer to help the scientific community make discoveries, without have a scientific background. It was already possible to help astrophysicists discover supermassive black holes at the heart of large galaxies by connecting online to Zoo Galaxy Radio as part of the famous Zooniverse. This popular citizen science portal is an extension of the original project Galaxy Zoo which invited Internet users to classify galaxies.
For some time anyone can go hunting for stellar black holes in the Milky Way with another avatar of Zooniverse : Black hole hunters.
Subrahmanyan Chandrasekhar and black holes. To get a fairly precise French translation, click on the white rectangle at the bottom right. English subtitles should then appear. Then click on the dice to the right of the rectangle, then on “Subtitles” and finally on “Translate automatically”. Choose “French”. © OpenLearn from the Open University
Wandering or isolated stellar black holes
What is it about?
We know that most stars in the Milky Way are double stars, often with at least one massive star that will end its short life in a supernova. If one of these stars is particularly massive, it is more likely that it will leave a black hole as a stellar corpse in place of a neutron star.
It may be that the resulting explosion dislocates the binary system, leading to a wandering stellar black hole. It is also possible that the orbits are modified or such that the black hole, although still gravitationally bound to the other star of the famous main sequence, is too far away to tear material away from the companion star.
In this case, an accretion disk does not form around the black hole where, so to speak, the coils of matter heat up until they radiate into the X domain as these coils rub against each other. friction for the gas flows involved) causing the matter to fall towards the event horizon of the black hole, this fictitious membrane under which according to the theory of general relativity the fallen matter remains irremediably trapped, because it would have to exceed the speed of light to escape to the bubble defined by the horizon.
A wandering black hole or one without an accretion disk would seem destined to escape the eyes of the noosphere and all hunters forever (hunters, in English) of black holes.
This animation illustrates the concept of gravitational microlensing with a black hole. When the black hole appears to pass almost in front of a background star, light rays from the source star are bent due to distorted spacetime around the foreground black hole. This becomes a virtual magnifying glass, amplifying the brightness of the distant star in the background. Unlike the case when the lensing object is a star or planet, black holes distort space-time so much that they significantly change the apparent position of the distant star in the sky. ©NASA
Transiting black holes with gravitational microlensing
But this is not true.
In fact, although the event is rare to surprise and requires long-term monitoring of as large a region of the sky as possible, it is possible that a black hole of this type transits in front of a star compared to an observer. Due to the black hole’s strong gravitational field, light rays are deflected, like a lens.
The star that undergoes a transit then becomes temporarily brighter, its luminous intensity curve therefore includes a peak and it is precisely this peak produced by what is called the gravitational microlensing effect that researchers Matt Middleton and Adam McMaster of the University of Southampton , and their colleague Dr Hugh Dickinson of the Open University (a public, open university located in the United Kingdom and founded in 1969) proposes that Internet users hunt down light curves recorded in research campaigns, initially intended to discover planetary transits.
So, for some time, the site of black hole hunters offered to dig into the SuperWASP data (Wide angle search for planets“wide-angle planet search”), an exoplanet search project that ran from 2004 to 2016 with ground-based telescopes at the sites of two observatories: the Roque de los Muchachos Observatory and the South African Astronomical Observatory.
But today these are the data Satellite for surveys of exoplanets in transit (Tess), now famous exoplanet hunter, who can be used.
Despite advances in artificial intelligence, these are still A wise man which can most effectively eliminate microlensing effects in light curves. Also, even if this is still the case, feel free to transform into Black hole hunter following the easy to put into practice instructions!
2024-01-23 20:12:53
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