European Southern Observatory (ESO) astronomers are astonished to find the closest black hole from Earth. The researchers are saying if you are in the Southern Hemisphere, you can observe this black hole with the naked eye at night. The reason one can so easily view it is that it is only a thousand light-years away from us!
Petr Hadrava
is the co-author of the paper published in Astronomy & Astrophysics, which
discusses this black hole. He is a scientist at the Academy of Sciences of the
Czech Republic, Prague. He explains how the team was surprised to realize that
they had found the first stellar system with a black hole that can be observed
from Earth unaided.
This
relatively dark black hole was rather difficult to spot for the scientists.
Black holes are known to flare up when they feed on their companion stars’
matter, which reveals their location to the astronomers. But this particular
one did not exhibit such behavior. So it had to be spotted only by tracking its
gravitational effect on 2 nearby stars. ESO’s La Silla Observatory in Chile
found this black hole with its 2.2-meter telescope.
The
researchers were initially observing this HR 6819 system for its 2 very closely
spaced stars. One of those stars was orbiting a black every 40 Earth days. So
the researchers studied its trajectory to conclude that the black hole was
quite big.
“An invisible object with a mass at least 4 times that of the Sun can only be a black hole,” Thomas Rivinius, lead author and ESO scientist, said in the statement.
The handful
of black holes discovered in our Milky Way were all discovered with the help of
the bright flashes of X-rays they gave away when they were interacting with
their environment. But the way our closest black hole was discovered, by
studying its gravitational effects, means there are many more such black holes
we can now find with this method.
Astronomers
are trailing another system LB-1 which they believe also has 3 bodies like the
HR 6819. LB-1 is further from Earth than HR 6819 but still relatively close,
said another co-author of the paper, Marianne Heida.
Image
credit: ESO/L. Calçada