Missing link' black hole lurks in strange binary system with red giant star

[Admin]

Astronomers have discovered a "missing link:" a tiny black hole lurking with a red giant star in a strange and difficult-to-explain binary system.

Missing link' black hole lurks in strange binary system with red giant star : Read more

 

[Unclear Engineer]

First, this article keeps switching between calling the visible star a "red giant" and a "red dwarf". It is a giant, not a dwarf. Somebody please fix that.

On to the science: To try to explain how a black hole and a red giant might be in orbit around each other, it seems like first we need to describe the orbit properly. This article says that the mass of the visible star is 2.7 solar masses, while the mass of the black hole is 3.6 solar masses. It describes the orbit of the visible star as "nearly circular", but it is orbiting the center of mass of the pair, not the black hole.

The article talks about black holes getting a "kick" in some direction due to some lack of exact symmetry in their collapse. But, that seems to be a random effect. So, unless there is some theory that shows a particular type of asymmetry always occurs during those supernova events, it seems reasonable that a few might not be unsymmetrical enough to produce much of a "kick".

Or, how about a "capture" scenario for a black hole that was not near the other star when it became a black hole? Getting a nearly perfectly circular orbit with a capture would seem to require a lot of "drag" on the black hole as it and the red giant pass each other. Is the red giants expanded outer layer big enough to cause much drag on a passing black hole? Some stars have generated large and rather dense "shells" of ejected matter over their lifetimes, such as Wolf -Rayet types - maybe there are other types as well. And, the relative velocity between the two might not have been very much to begin with when they tried to "pass" on their original paths.

 

[Questioner]

Plunging in with my (latest) hypothesis that BHs are actually singularities due to contracted space of mass fields.

A singularity cannot respond gravitationally.

Other non-absolute zero, non-singularities can however respond gravitationally to a singularity's mass field. Making it one-sided gravity.

The near circular orbit of the red giant fits that very neatly.

The pair may have been spiraling towards one another prior to the supernova,
& now with only one-sided gravity a stable orbiting is what remains.

A singularity/BH post [super-]nova ends with whatever inertia it had at that time.

Which means if a binary pair's orbit depended on mutual gravitational response one side or that orbit inward acceleration is gone when one of them becomes a BH.

The one-sided gravity may be insufficient to sustain the pairing.

That might likely have the luminal partner wandering off leaving the BH isolated and difficult to identify.

So perhaps small BHs tend to be isolated and difficult to find rather than being actually smaller of population.