Black Hole Resumes Star Binging After 26-Year Recess
Astronomers are a busy lot these days and understandably so, as a black hole dormant for 26 years, recently woke up to provide once-in-a-lifetime glimpse at its feeding habits.
Telescopes across the world have been trained at the Cygnus Constellation, which houses the V404 Cygni system, a binary with an orbiting star and black hole. The black hole is known to be feeding on the star and the last burst of optical activity was seen in 1989. The constellation is 8,000 light years away. The star is about half as a massive as the Sun while the black hole weighs 12 solar masses.
On June 15, NASA's Swift satellite detected a sudden burst of gamma rays in the night sky, alerting telescopes on Earth and in space. Soon telescopes with varied capabilities from optical to gamma-ray imaging began making observations. The system is said to be very active now.
"The behavior of this source is extraordinary at the moment, with repeated bright flashes of light on time scales shorter than an hour, something rarely seen in other black hole systems. In these moments, it becomes the brightest object in the X-ray sky - up to fifty times brighter than the Crab Nebula, normally one of the brightest sources in the high-energy sky," said Erik Kuulkers, Integral project scientist at ESA.
Archival data of the black hole shows peak in activity every two to three decades, when the rate of material absorption into the black hole increases as the material piles in the accretion disc.
