Tucson AZ (SPX) May 16, 2022 Discovering something for the second time doesn't usually have...
That's exactly what happened in the case of Sgr A*, the second black hole imaged.
In 2019, the image of M87*, a supermassive black hole in a galaxy more than 50 million light-years from Earth, graced the cover pages of virtually every news outlet across the world.
In that paper and a follow-up paper published in 2001, she identified M87*, the first black hole ever to be imaged, and Sgr A* as the two ideal black holes that presented even a remote chance of having their pictures taken.
One of the most fundamental predictions of Einstein's theory of gravity, Psaltis said, is that the image of a black hole scales only with its mass.
A black hole 1,000 times smaller in mass than another will have a very similar image that will just be 1,000 times smaller.
Their stark simplicity is what makes the two black hole images so important, Psaltis explained, because they confirm what until now had only been predicted by theory: They appear to be the only objects in existence that only answer to one law of nature - gravity.
If scientists could take a picture of a truly small black hole of about 10 solar masses - which is not possible, because even the Earth-sized EHT does not have the necessary resolution power - and compare it to M87*, which has 6 billion times the mass of the sun, the two would look very similar, according to Psaltis.
The 'Goldilocks black holes' Black holes are such alien objects that even Albert Einstein struggled to reconcile their existence.
SpaceDaily Monthly Supporter$5+ Billed Monthly SpaceDaily Contributor $5 Billed Once credit card or paypal Astronomers reveal first image of black hole at Milky Way's centre Paris, France May 12, 2022.
An international team of astronomers on Thursday unveiled the first image of a supermassive black hole at the centre of our own Milky Way galaxy - a cosmic body known as Sagittarius A*. The image - produced by a global team of scientists known as the Event Horizon Telescope Collaboration - is the first, direct visual confirmation of the presence of this invisible object, and comes three years after the very first image of a black hole from a distant galaxy.