Sagittarius A* is a suspected supermassive black hole located at the center of our Milky Way Galaxy. It is located approximately 26,000 light-years from Earth. There are a number of stars orbiting Sagittarius A* and a few have a remarkably short orbital period. The orbiting stars are visible in the imagery of advanced technology telescopes that apply the principle of adaptive optics to correct for turbulence in the Earth’s atmosphere. One of the stars has a period of 15.6 years and it is known as SO-2 (also S-2). The semi-major axis of SO-2’s orbit about Sagittarius A*are and the mass of Sagittarius A* (also known as Sgr A*) are used to calculate the velocity of SO-2 at periastron and apastron. The two velocities are calculated by applying the equations for the conservation of energy and the conservation of angular momentum. At periastron, the velocity of SO-2 is approximately 2.4 % of the speed of light. An astonishing high speed for a star. ERRATA: The mass of Sgr A* was listed as about 4 million Suns, but it was incorrectly read as 4 billion. Oops! Andrew R. Ochadlick Jr. received a Ph.D. in Physics from the State University of New York at Albany (SUNYA) and is a career physicist with university, government and industry R&D experience and teaching experience at the undergraduate and graduate level. He may be reached at
[email protected] .
