The black hole–part of a binary system called V404 Cygni, located about 7,800 light-years away from Earth– is actively pulling material away from a companion star — with about half the mass of the Sun — into a disk around the invisible object creating acolossal set of rings, has been captured using NASA’s Chandra X-ray Observatory and Neil Gehrels Swift Observatory. The giant rings, which glow in X-rays, so astronomers refer to these systems as “X-ray binaries,” have revealed new information about dust located in our Galaxy.
A new view of star formation in our home galaxy has revealed some previously hidden secrets. Astronomers using two of the world’s most powerful radio telescopes have made a detailed and sensitive survey of a large segment of the Milky Way, detecting previously unseen tracers of massive star formation, a process that dominates galactic ecosystems and solving the mystery of the galaxy’s missing supernova remnants.
“There are only about five dozen known black holes in the entire galaxy—120,000 light years wide—and there are supposed to be 10,000 to 20,000 of these things in a region just six light years wide that no one has been able to find,” said Columbia University astrophysicist Chuck Hailey, co-director of the Columbia Astrophysics Lab, adding that extensive fruitless searches have been made for black holes around Sgr A*, the closest SMBH to Earth and therefore the easiest to study. “There hasn’t been much credible evidence.”
“These pristine stars are among the oldest surviving stars in the Universe, and certainly the oldest stars we have ever seen,” said astronomer Louise Howes currently at Lund University, who was a member of a 2015 team along with the University of Cambridge who discovered stars that date from before the Milky Way Galaxy formed, when the Universe was just 300 million years old.
In 1999 astronomers focusing on a star at the center of the Milky Way, measured precisely how long it takes the sun to complete one orbit (a galactic year) of our home galaxy: 226 million years, bobbing our fraught journey through the disc of the Milky Way, drifting through ghostly spiral arms and the darkness of dense nebulae, keeping a constant 30,000 light years between Earth and the violent galactic core. The last time the sun was at that exact spot of its galactic orbit, Tyrannosaurus rex ruled the Earth.
Mapping the entirety of our home galaxy is “the most Important thing in astrophysics –Optically, it’s like trying to look through a velvet cloth—black as black can be. In terms of tracing and understanding the spiral structure, essentially half of the Milky Way is terra incognita,” says Thomas Dame, Director of the Radio Telescope Data Center at the Harvard-Smithsonian Center for Astrophysics and Senior Radio Astronomer at the Smithsonian Astrophysical Observatory.