The astronomy of gravitational wave is still in its early stages. To extend the views on these indications many observatories like LIGO, North American Nanohertz Observatory for Gravitational Waves (NANOGrav) have started a new window keeping the view of cosmos in limited. The gravitational waves are created by the massive objects that are moving in the space and most of them are created by merger of black holes. During this merger what binary black holes will do they’ll simply orbit each other quickly and produce strong gravitational waves. The waves that ripples in the space are neither strong nor rapid. Orbiting black holes and their unclear echoes that are not about to merge creates a background of gravitational waves.
To notice those background gravitational waves scientists and astronomers at NANOGrav observe the radio pulses of rotating neutrons also known as millisecond pulsars. They are so regular that a movement in their pulse rate is caused by a motion in earth. These background gravitational waves are very slow in nature and it takes years to observe the movement in pulsars due to them.
The astronomers at NANOGrav are observing the pulsars from 12 years or more and also they have published the initial result. The 45 millisecond pulsars are having steady pulse rates. All the pulsars have been observed for at least three years and also some of them are for 12 years. They also figured out the fake noise effects that appears to be a background gravitational waves with 1 year of oscillation period. It still seems like a long time after a decade of observation by the astronomers and to understand them well they need to keep observing for much longer.