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Artist concept of black hole pulling a blue star

Flickering black hole observed by astronomers in great detail

Astronomers have observed a flickering black hole in the Milky Way in an amazing detail with the help of a high frame-rate method that has helped to understand the dynamics of these cosmic objects. MAXI J1820+070, the black hole was discovered in 2018. It is nearly 7 times the weight of Sun and is at a distance of 10000 light years from Earth. The findings appear in the Monthly Notices of the Royal Astronomical Society journal. 

In comparison to other black holes, it ways much lesser as the “lightest” black hole has a mass of 5 Suns. Besides this, it is flickering and emits X-rays and visible radiation as it consumes matter from a surrounding star. 

Small black holes are normally very hard to observe. The supermassive black hole at the centre of the Universe, Sagittarius A*, although quiet is easier to view since we can observe the orbits of the objects around it. Sgr A* weighs nearly 4 million times that of Sun, acting as the centre of a huge system. But a black hole that weighs only 7 times that of Sun would not have many orbiters. Several stars are in a binary system, where the black hole can consume material from their companions. 

Astronomers think that this is occurring with MAXI J1820+070 where it is consuming matter from its companion star, the material forming an accretion disc around it in which frictional and magnetic forces compress it producing a high amount of heat. This process results in flickering electromagnetic radiation which has been captured by researchers at a frame rate of 300 fps in optical light with the help of HiPERCAM on Gran Telescopio Canarias and X-rays from NICER observatory, NASA on the International Space Station. 

John Paice, astronomer at the University of Southampton said that the movie was created using real data, although slowing the speed by 10 times so that the rapid flares can be differentiated by the human eye. He added that the material surrounding the black hole can be observed to be bright enough to outshine the star which is being consumed. The fastest flickers last only few milliseconds which is more than the rays from hundred Suns emitted in a blink. 

This approach helped to track both radiation types where rise in one meant a rise in another. However a time gap was observed as the X-ray flashes preceded the optical light flashes by a split second which according to the researchers is an indication of plasma, very close to the black hole. This delay was also observed accreting black holes in 2017 and 2018 clearly indicating a pattern. 

Poshak Gandhi, astronomer at the University of Southampton said that the observation in three systems indicates that it is a characteristic of such black holes. It would help in understanding the flow of plasmas around black holes. This is very important data as these are extreme physical conditions which cannot be replicated in Earth. 

air pollution smoke rising from plant tower

Latest estimates of atmospheric carbon dioxide shows horrifying future ahead

Human actions have depleted the natural resources of the planet to a great extent. From polluting the atmosphere, depletion of fossil fuels to harming aquatic life, human footprints have been literally everywhere. The price has to be paid by the coming generations.

Calculations by scientists showed that the carbon levels reached an all-time high of more than 415 parts per million in the middle of May. For the second time in the span of two months, researchers at Scripps Institution of Oceanography and NOAA have bad news to be shared.

The team of researchers recorded the highest monthly average of carbon dioxide above the largest volcano in Hawaii since measurements began 61 years ago. The number is 414.8 parts per million, which has been the greatest of the increase in measurements made every year in May. Researchers at Mauna Loa Atmospheric Baseline Observatory have been recording the values from 1958 and the values have been plotted on a curve known as “Keeling Curve“- after Charles David Keeling who observed a strange trend. The results have been published by The Scripps Institution of Oceanography.

When the measurement began, the average annual increase of carbon dioxide was approximately 0.7 ppm. It increased to 1.5 ppm in the 1990s and in 2000s it had a value of 2.2 ppm. In 2019, both NOAA and Scripps found that this May monthly average – the highest point each year – is 3.5 ppm higher than it was in 2018. So, the annual change in CO2 is now 3.5 ppm per year. While a single reading can be dismissed, this continuous increment cannot be ignored.

Ralph Keeling, director of the CO2 program at Scripps and son of Charles Keeling commented that the human intervention in the earth’s atmosphere can be clearly observed as we focus on the bigger picture. Most of this change is due to the extremely high usage of fossil fuels which has led to search for more greener sources of energy. Climate model projections do not give us the current state of the atmosphere and they tend to overlook the alarming situation of global warming. However, these measurements are real time and give us an overview of our situation and where we are heading to.

Pieter Tans, an atmospheric scientist with the Global Monitoring Division of the NOAA remarked that it is very essential to have the correct, long term measurements of the carbon dioxide levels to get a clear understanding of the changes caused by fossil fuel pollution to our climate.

There have been many proposals on how to tackle the problem of global warming, but without a sharp decline of the carbon dioxide emissions, the proposals are borderline useless.