Black hole gravity response question

[Voltage]

Can anybody tell me if there are any puzzles or anomalies with respect to candidate black holes? For example if we have a binary system that looks like this:

o O

where the o is a candidate black hole and the O is a star of some typical type and mass, one would observe each object orbiting the other. Does anybody know if there's have been any unusual observations or inferences?

Thanks in advance.

 

[Voltage]

This is the sort of thing I meant. Can anybody advise or inform please?

http://www.iop.org/EJ/abstract/1742-6596/66/1/012039

Abstract: The recently discovered anomalous orbital velocity effect, which implies a reduced velocity with decreasing radius for an orbiting test particle, is present in extreme Kerr black holes with spin > 0.9953 and radii between 1.05 and 1.78 gravitational radii. In this region a 3:1 resonance between the vertical and the radial epicyclic frequencies occurs, which may lead to quasi-peridoc light variations with two periods differing by a factor of 3. Such variations may have been observed from the Galactic Center black hole Sgr A*. At the same spin but at a larger radius a 3:2 resonance between the two epicyclic frequencies is found as well. Such 3:2 frequencies have been observed in four galactic microquasars. In either case, i.e. the 3:1 or the 3:2 resonance, the black hole mass determined from this model agrees very well with the dynamical mass for Sgr A* and each of the four microquasars. Meanwhile the microquasar GRS 1915+105 has been classified by its X-ray spectrum as an extreme Kerr black hole with a spin > 0.98 [1], which agrees quite nicely with our prediction for the spin, i.e. a = 0.996. Model and observational data are presented and discussed.

I'll perhaps search a variety of papers then print and study.

 

[sir-pinski]

There are indeed some puzzles and anomalies with respect to candidate black holes in binary systems. One of the most notable is the phenomenon of X-ray binaries, where a candidate black hole is observed to be emitting high energy X-rays as it accretes material from its companion star. This is puzzling because according to our current understanding, black holes do not emit any kind of radiation. This has led to the development of theories such as the existence of a "hot disk" of material around the black hole, which could explain the X-ray emission.

Another anomaly is the observation of supermassive black holes at the center of galaxies. These black holes have masses ranging from millions to billions of times the mass of our sun, which is much larger than the typical mass of a stellar black hole. This has raised questions about how these supermassive black holes formed and how they continue to grow.

In addition, there have been some unusual observations and inferences in binary systems involving black holes. For example, in some cases, the companion star in a binary system has been observed to have an elliptical orbit rather than a circular one, which could be indicative of the presence of a black hole. There have also been cases where the companion star appears to be "missing," which could be due to the gravitational influence of a black hole.

Overall, while our understanding of black holes has come a long way, there are still many mysteries and puzzles surrounding these enigmatic objects. Further research and observations are needed to fully understand and explain these anomalies and to continue unraveling the mysteries of black holes.