P4_6 Orbiting a Black Hole

Lilian Garratt-Smithson, Jason Watson, Magdalena Szczykulska, Alistair Muir


During the BBC's classic science fiction show Doctor Who, the Doctor and his assistant Rose land the TARDIS on a planet that is orbiting a black hole - an 'impossible situation' according to the Doctor. This paper calculates the minimum radius and required angular momentum of the closest stable circular orbit around a Schwarzschild black hole of comparable mass to the one at the centre of the Milky Way (named Sagittarius A*). The minimum radius is found to be 3.54x1010m while the angular momentum required to sustain this orbit is 2.04 x1010m2s-1kg-1.

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