Astronomers Calculate Largest Mass Black Holes
Measuring 6.6 billion solar mass black hole in the center of the galaxy M87 is the largest black hole where the mass has been measured precisely.
By using the Frederick C. Gillett Gemini Telescope on Mauna Kea, Hawaii, a team of astronomers to calculate the mass of the black hole, which is larger than the black hole is located in the center of the Milky Way, which is about 4 million solar masses.
Astronomer Karl Gebhardt of the University of Texas, Austin, presented the results of the research team on Wednesday, January 12, in the 217th meeting of the American Astronomical Union. He said that the horizon of the black hole, which is 20 billion km, four times larger than the orbit of Neptune and three times bigger than the orbit of Pluto. In other words, the black hole can "swallow" the whole of our solar system.
Previous astronomers have estimated the mass of the black hole is about 3 billion times the solar system, so their results are somewhat surprising. To calculate the mass of the black hole, the astronomers measured how fast the stars in orbit around the black hole. They found that, on average, the stars orbit at speeds of nearly 500 km per second (for comparison, the sun orbits the black hole at the center of the Milky Way galaxy about 220 km per second). From these observations, the astronomers conclude that the most accurate estimate of the mass of the black hole that is super big.
Astronomers assume that the M87 black hole grow to be very big by joining with several other black holes. M87 is the largest galaxy in the nearby universe, and were formed by the merger of approximately 100 galaxies were smaller.
Although the black hole is located about 50 million light-years away, he is regarded as our neighbors in the perspective of cosmology. Because of the large size and relative proximity, astronomers assume that it is the first black holes that they can actually "see". So far, no one has ever found evidence of direct observation of black holes. Their existence is inferred from indirect evidence, particularly how they affect their surroundings.
M87 black hole probably would not long retain his title, since astronomers plan to continue looking for and calculate measurements of many other black holes. One planned project involves connecting telescopes from around the world to observe the universe at wavelengths shorter than one millimeter. This might allow scientists to detect black shadow of the M87 black hole horizon. It may also allow scientists to calculate the size of other black holes located in a galaxy about 3.6 billion light-years.
More information can be found at http://news.sciencemag.org/sciencenow/2011/01/the-solar-system-swallower.html.
