Astronomers are excited about the quality of pictures they’re getting back of far-away galaxies using a new kind of instrument called an Event Horizon Telescope. Or, more accurately, entire arrays of EHTs. They say these are the highest resolution pictures ever taken from the ground of our planet.
With the new technology, stargazers may be able to get clear images of what are called “supermassive black holes.” Black holes are stars that have collapsed under their own weight into a small space. They are so dense that their gravitational fields prevent even light from escaping. Because of this, we can’t see them directly, but must notice spots in the sky with an absence of light. They can also sometimes be seen when the disk of matter around a black hole ejects X-rays and other energy.
The term “event horizon” refers to the small area around a black hole from which light and matter can escape.
The most detailed images we have so far of supermassive black holes depict one called *M87, which is 55 million light years from Earth, and Sagittarius A*, the name for the huge black hole at the center of the Milky Way galaxy.
So far the entire array of EHTs has not been brought online, and that will be required to get more detailed pictures of astronomical bodies like supermassive black holes. But tests using a limited number of the telescopes have been successful in capturing images of the universe said to give the finest detail yet.
Astrophysicist Alexander Raymond of the Jet Propulsion Laboratory at NASA said the first pictures of black holes taken with some of the scopes measured light down to a wavelength of 1.3 millimeters. This was enough to get a picture, but not a sharp one. Astronomers could see a “bright ring” around the black hole caused by light getting bent around the object by its strong gravity, but the pictures “still looked blurry,” Raymond said.
But researchers expect to be able to capture light at a frequency of just .87mm, which will improve the resolution substantially.
To boost what they can see and photograph, astronomers often combine information from various telescopes from around the globe. When treated this way as an “array,” and by interweaving the data from all of them together, it effectively gives a telescope view the size of the earth, greatly increasing the amount of information gathered.
