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Still exciting. Do we have any other examples of stars closely orbiting around black holes?

• daniel-thompson 3y ago
  [1] S62 comes within 16 AU at closest approach to Sag A* but its orbit is highly elliptical. The distance between objects in this system 1.4 AU, which is _incredibly_ close. https://en.wikipedia.org/wiki/S62_(star) https://en.wikipedia.org/wiki/S62_(star)
  • dylan604 3y ago
    Do we know the distance to the event horizon for Sgr A*? I'm no astrophysicist, but 1.4AU sounds really _incredibly_ close. In my sci-fi thoughts, something at 1.4AU would be attempting to go "in, through, and beyond" and not orbiting. So excuse me while I try to re-evaluate whatever pre-existing notions I might have
    • daniel-thompson 3y ago
      I'm no astrophysicist, but the paper and some web data show - Sag A* has a mass of ~4,000,000 times the sun, and an event horizon of approximately 12,000,000 km (0.08 AU). This is just the event horizon; Sag A*'s accretion disk has a diameter of about 150,000,000,000 km (1000 AU). So your intuition would certainly be right about Sag A* - there is a huge disk of gas and other junk you'd be flying through. - This object has a mass of at most ~12 times the sun, and (if it's a black hole) an event horizon of approximately 35 km. The paper doesn't say anything about an accretion disk given that it's exploring the idea that the object is not a black hole. Regardless, a star orbiting at 1.4 AU would probably clear out everything in the immediate neighborhood.
• wrycoder 3y ago
  Yes, that's why they published it.