In what ways are LB-1 and HR 6819 similar and dissimilar? They are similar in almost every aspect. The inner , as far as we can tell at the moment. The B star that is close to the black hole [of LB-1] is rotating even slower than in HR 6819. It could be that it has been a bit modified: that it already has either transferred mass to the black hole or the progenitor of the black hole has transferred mass[...] For [HR] 6819, there's no such indication. But otherwise, we believe they are essentially the same. In what ways would the be different if the Sun was in the inner star's orbit, orbiting this black hole? It would not exist. As I said, planets simply would not form around such a massive binary. Planet formation around binary in principle is possible. But the inner star would have been a star with at least 12, maybe 20 solar masses. And these stars form very quickly, burn very quickly, die very quickly. Planets would simply not have had the time to form along such an object. No, considering our Solar System was there. Right now? Well, if you just put a Solar System there, that exists, it would probably destroy Mercury, it wouldn't exist, it would be not in a stable orbit. Probably also Venus would not be in a stable orbit. In the region of Earth, the orbit could be stable. So maybe Earth could just so barely exist. The would be different. There would be a strong 40-day modulation, which makes every 20 days — or every 40 days you get a lot of radiation. Every 40 days, you get only much less radiation. So it would be very hostile to life. 700px| of the inner B3 III star ( iλ4026) What were the different radiation emissions observed in this system? There is only visible light so far. We know of no other []. What are some of the other observed systems that have similar radiation emission? As I said, this is from the point-of-view of the stars, these are just normal stars. And the black hole does not contribute anything to the emission of the radiation. What does the future of these stars look like? The outer star will just evolve very normally just like any other star of its mass. The inner star will become a as well. But when it ends its supergiant phase, it will be big enough to get accounted into the black hole and then the black hole will start accreting. It is hard to say what happens then. It may get big enough for the black hole to actually fall into the star, and then shortly after the star falls into the black hole, or it might end with the accretion. So you are saying there is a chance the black hole may create an accretion disk feeding on this inner star? It will certainly. But it will take another few million years. What is your role at the ESO? At the ESO, I am a science operations astronomer. Which means that I run the telscopes; I support other astronomers when they come here to conduct the observations, and when they cannot come, or do not want to come which also happens, I do the observations for them. And I do this about 60\% of my working time, I work for the observatory in this capacity, and one third of my working time I do my own research. Well, those were all the questions I had for you. Is there something you would like to add? No, I think that was fine, thank you. Thank you for agreeing for this interview. It had been a great pleasure discussing this with you. ' Thank you. Ciao '' .
In what ways are LB-1 and HR 6819 similar and dissimilar? They are similar in almost every aspect. The inner , as far as we can tell at the moment. The B star that is close to the black hole [of LB-1] is rotating even slower than in HR 6819. It could be that it has been a bit modified: that it already has either transferred mass to the black hole or the progenitor of the black hole has transferred mass[...] For [HR] 6819, there's no such indication. But otherwise, we believe they are essentially the same. In what ways would the be different if the Sun was in the inner star's orbit, orbiting this black hole? It would not exist. As I said, planets simply would not form around such a massive binary. Planet formation around binary in principle is possible. But the inner star would have been a star with at least 12, maybe 20 solar masses. And these stars form very quickly, burn very quickly, die very quickly. Planets would simply not have had the time to form along such an object. No, considering our Solar System was there. Right now? Well, if you just put a Solar System there, that exists, it would probably destroy Mercury, it wouldn't exist, it would be not in a stable orbit. Probably also Venus would not be in a stable orbit. In the region of Earth, the orbit could be stable. So maybe Earth could just so barely exist. The would be different. There would be a strong 40-day modulation, which makes every 20 days — or every 40 days you get a lot of radiation. Every 40 days, you get only much less radiation. So it would be very hostile to life. 700px| of the inner B3 III star ( iλ4026) What were the different radiation emissions observed in this system? There is only visible light so far. We know of no other []. What are some of the other observed systems that have similar radiation emission? As I said, this is from the point-of-view of the stars, these are just normal stars. And the black hole does not contribute anything to the emission of the radiation. What does the future of these stars look like? The outer star will just evolve very normally just like any other star of its mass. The inner star will become a as well. But when it ends its supergiant phase, it will be big enough to get accounted into the black hole and then the black hole will start accreting. It is hard to say what happens then. It may get big enough for the black hole to actually fall into the star, and then shortly after the star falls into the black hole, or it might end with the accretion. So you are saying there is a chance the black hole may create an accretion disk feeding on this inner star? It will certainly. But it will take another few million years. What is your role at the ESO? At the ESO, I am a science operations astronomer. Which means that I run the telscopes; I support other astronomers when they come here to conduct the observations, and when they cannot come, or do not want to come which also happens, I do the observations for them. And I do this about 60\% of my working time, I work for the observatory in this capacity, and one third of my working time I do my own research. Well, those were all the questions I had for you. Is there something you would like to add? No, I think that was fine, thank you. Thank you for agreeing for this interview. It had been a great pleasure discussing this with you. Thank you. Ciao .
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