In a paper published in Science this week, scientists have discussed their observations of the black hole part of the binary star system and microquasar V404 Cygni, which is nearly 8,000 light years away, in the Cygnus constellation.
The scientists have found that, contrary to popular belief and adding a new challenge to existing theories, the magnetic energy surrounding the black hole is some 4,000 times less than previously estimated.
Apart from helping scientists understand black holes better in general, this discovery will also contribute to solving some long-standing puzzles – such as the reasons for the existence of jets of particles travelling at high speeds close to that of light that shoot out of some black holes.
V404 Cygni
V404 Cygni is a very interesting star system. Located in the Cygnus constellation, it is actually a binary object – a pair made up of a moderate-sized black hole having about 9-10 times the mass of our sun and a companion star, which is large and with mass slightly less than the sun.
The two objects revolve around each other and the black hole, because of its enormous gravity drags in the mass from its neighbour. The dragged mass accretes in the form of a disc around the black hole. The pull of the black hole also accelerates the mass, and the accelerated charged particles in the mass start radiating energy.
The V in V404 Cygni stands for “variable.” This is because, when observed from the earth, the star system appears to glow and fade. The star also produces outbursts of energy and the last time this happened was in 2015.
The authors of the paper include scientists from several countries who have observed V404 Cygni through infra-red, optical, x-ray and radio telescopes. The lead authors are from University of Florida, U.S.
