Since the orbit is circular, that implies the explosion that formed the black hole was symmetrical, spherical. That in turn would make the orbit more elliptical. Many times, the supernova explosion that forms a black hole is off-center, blowing out more to one side than the other, and that creates a powerful kick that acts like a rocket thrust.
The orbit of the star and black hole is fairly circular, which is again a little surprising. Conditions in VFTS 243 don’t allow a disk to form, so no X-rays are expected. However, as the astronomers point out, that matter has to pile up and form a disk around the black hole before falling in the disk gets extremely hot and that’s what produces X-rays. That’s actually a little odd, since massive stars have powerful winds of subatomic particles, like the solar wind on steroids, and if this matter were to get eaten by the black hole that would normally produce X-rays. The astronomers looked at deep X-ray observations and found no hint of them from VFTS 243, so if this is a black hole - and it does appear to be - it’s getting nothing from the O star. The only thing known that can be that massive and utterly dark is a black hole.Īrt depicting a black hole (lower right) orbiting a more massive star, the light from the star distorted near the black hole due to the intense gravity. If it were a star like the Sun that would make it very bright, and easy to spot. The size and shape of the orbit can be determined by the shift, as well as the mass of the other object.Īnd that’s the fun bit: The observations indicate the second object has a mass of about 9 times the Sun. This is exactly what you expect if it’s in orbit around another object like a star. The spectrum undergoes a Doppler shift, with the wavelengths lengthening and shortening by a small amount, and this pattern is periodic, repeating every 10.4 days. This can be seen by taking a spectrum, breaking its light up into individual colors, and examining the wavelengths. Here’s where it gets interesting: Careful observations of VFTS 243 show that’s it’s in orbit around something. Many very massive stars are forming in it, making it a great target to keep an eye on what stars like that do. It’s one of dozens of such stars being monitored in the Tarantula Nebula, itself a ridiculously huge gas cloud that is forming millions of stars - millions the Orion Nebula is the nearest big starbirth factory to us and it’s only making some dozens of stars. It’s a beast.Ī small section of a huge image of the Tarantula Nebula, a sprawling star-forming gas cloud in a nearby galaxy. It’s what we call an O-type star with 25 times the Sun’s mass and a brain-frying 160,000 times the Sun’s luminosity. The normal star is “normal” in the sense that, like the Sun, it’s fusing hydrogen into helium in its core, but it’s actually extraordinary in that it’s very massive and luminous. It’s in the Large Magellanic Cloud, a smallish galaxy that orbits our Milky Way, and one of the closest galaxies in the Universe to us. The candidate is in a star system called VFTS 243. Ironically, this black hole candidate was found by a team of astronomers known to destroy other astronomers’ claims of finding black holes! Instead, it’s revealing itself through its powerful gravity, tossing around its binary companion. And, while it does appear to orbit a normal star, it’s not feeding, so it’s not giving off X-rays.
However, a very promising candidate stellar-mass black hole has been found in a neighboring galaxy. And in all those cases they betray their presence by eating matter from a companion star, causing them to glow brightly in X-rays. $(this).closest('#scFooterRegistrationFormConfigWrapper').find('.Despite years of searching for stellar-mass black holes - ones up to a few dozen times the mass of the Sun that form when massive stars explodes - not that many have been found.
0 kommentar(er)
