Monday, September 1, 2008

Super massive

Six years ago(2002), the word "super massive" found a right example. It was the discovery of Sagittarius A*, a super massive black hole in the center of our Milky Way Galaxy. Recently Astronomers confirmed it's existence. The numbers corresponds to this so called "super massive" black hole, will make us to think whether the word "super massive" is sufficient to describe the magnitude of it's unimaginable mass and physical properties.

It has mass of 2.6(+/-0.2) million solar mass, confined in a volume with radius no more than 17 light-hours.(Remember light hour is nothing in astronomy compared to usual distances measured in light-years).In order to show the magnitude let me calculate and express in kg. One solar mass is equal to 1.98892x10^30 kg. So 2.6 million solar mass is equal to
5171192000000000000000000000000000000 kg.

It's interesting to know how they detect the black hole, since nothing comes out(of course something is coming out called Hawking radiations) of a black hole. Its very simple, they observe the movement of stars. If they found stars mysteriously orbit around some invisible point, they suspect that there might be a black hole in the center. By calculating the mass of the orbiting stars and its period, they estimate the mass of the black hole using Kepler's Law.(Note: I am typing this article from the place where Kepler spent last part of his life :) ).

At last I would like to mention one very interesting fact, even though I don't believe in Astrology, I am now proud to say that my sun sign is Sagittarius.Have a nice day :)

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