The Universe

Black Holes

Where are some black holes located in our galaxy?

However, if someone fell into a supermassive black hole with a low density, there would be no such tidal forces to contend with. In that case, the relativistic effects of being near the event horizon of a black hole would become apparent. As the person fell closer and closer to the event horizon, his or her speed would get closer and closer to the speed of light, and the passage of time would get slower and slower. Eventually, the person would move so slowly through time that he or she would effectively freeze, never reaching the event horizon. In fact, the event horizon will grow outward to meet the person. As it did so, the person’s body would change from matter into energy, following the formula E = mc2, and disappear into the black hole forever.

Black Holes in the Milky Way Galaxy
Name Probable Mass in solar masses Approx. Distance from Earth in light-years
A0620-00 9–13 3,000–4,000
GRO J1655-40 6–6.5 5,000–10,000
XTE J1118 480 6.4–7.2 6,000–6,500
Cygnus X-1 7-13 6,000–8,000
GRO J0422 32 3–5 8,000–9,000
GS 2000-25 7–8 8,500–9,000
V404 Cygnus 10–14 10,000
GX 339-4 5–6 15,000
GRS 1124-683 6.5–8.2 17,000
XTE J1550-564 10–11 17,000
XTE J1819-254 10–18 less than 25,000
4U 1543-475 8–10 24,000
Sagittarius A* 3,000,000 Center of the Milky Way


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