For this dead star, 72 Earth years is a single day

[Admin]

Astronomers have discovered a remarkable binary system in which a dead white dwarf star orbits a tiny stellar companion 72 times in 24 hours. The observation could help explain how tiny stars are born.

For this dead star, 72 Earth years is a single day : Read more

 

[billslugg]

Undefined terms:
"Earth year". - Is it referring to a 365 day period or is it referring to revolving around a host star one time?
"Earth day" - Is it a 24 hour period or is it one turn on it's axis? Is it rotationallty locked?
And what exactly is the lower boundary in m/s on "whips"? Just curious.

 

[Unclear Engineer]

Yes, Bill, the wording was sloppy. It also says the more massive star " whips around its blisteringly hot and tiny stellar companion" that has less mass. Saying it the other way would be closer to the truth, which is that both orbit a common center of mass.

Anyway, what this article did not say is what I am wondering about. Will this two star system ultimately merge into a single star that rotates extremely fast and becomes an extremely short period emitter of electromagnetic radiation, such as a pulsar? Is this how all pulsars are formed?

 

[Helio]

Yeah, it can be confusing when time is used to represent orbital angular distance, though time is the more common tool people prefer to use.

It would be interesting to learn how soon these merge. No doubt the growing strength of their gravity waves is causing an exponential decay rate.

[Added from… Here….

The astronomers assume that the J0526 system is currently detached. They predict that after about 1.5 million years, J0526B will overflow its Roche lobe and transfer mass toward J0526A at an orbital period of around 14 minutes. This will lead to the formation of an AM CVn star through the helium-star channel.

The researchers noted that J0526B will begin a transition to a degenerate state, which may lead to the formation of a helium-core white dwarf. They added that when the electron-degeneracy pressure becomes dominant, J0526B will reach the minimum orbital period of about nine minutes and it will start to expand with its mass loss. This will probably lead to an increase in orbital period as predicted by binary evolution theory.]

So its orbital period and distance will shrink then enlarge. How ‘ bout that!