Researchers Say Black Holes Now Visible Through Naked Eyes

According to a research conducted by the scientists in Kyoto University, black holes can now be observed without powerful telescopes. The team was able to develop a technique that observes the Black holes' outbursts as a basis for its monitoring. Such a feat has been previously deemed impossible by astronomers as high-spec X-ray or gamma-ray telescopes are required to view the celestial phenomenon.

Black holes are areas in space where ordinary gravity is so strong that not even the light can escape from it. Over the years, research has been extensively done on its existence and behavior.

As published in Nature, the study suggests that as visible light during a black hole's outburst is emitted, the flickering light from nearby gases can be used as an indicator -- using optic rays may provide more reliable data for its observation.

According to Kyoto University lead researcher Mariko Kimura, the ability to observe black holes without the use of high-spec X-ray or gamma-ray telescope is a result of their study that reveals optical rays can be used to observe black holes more easily even by using a 20 cm telescope.

These observable outbursts, which happen in decades throughout their existence, result in large amounts of released energy with temperatures reaching 10 million degrees Kelvin or more. Surrounded by the accretion disk, gases from nearby stars are then drawn to the hole in a spiral pattern. These phenomena are commonly observed through X-rays.

The study also discovered that these continual variations occur at mass accretion rates lower than one tenth of what was previously thought. This reveals that the volume of mass accretion is not the foremost factor that triggers repetitive activity around black holes, but rather the periods of its orbits.

The research focused on V404 Cygni, one of the black holes binaries thought to be nearest to Earth, which also became active as it underwent an outburst on June 15, 2015. The letter "V" refers to variable star, which light continuously becomes stronger and fainter over time.

V404 Cygni emitted repetitive patterns having timescales of some minutes to just a few hours -- detecting the resulting patterns of the optical fluctuation correlated with those what the X-rays emit.