We don't have to worry about the sun a lot. It can cause burns, and it can cause solar storms that can damage electrical systems. Things are more predictable because the Sun is alone up there.
Other stars are locked in relationships with each other A new study shows that a pair of stars are so close to each other that they don't travel long distances. They're close to one another.
The stars are called cataclysmic variables. The primary star is a white dwarf and the other is older. White dwarfs are small for stars but dense. The white dwarf is pulling material away from the donor star. An accretion ring surrounds the white dwarf. Bright flashes can be seen at irregular or variable times as material falls into the white dwarf.
To get material from the donor star, the stars must be close together. Astronomers know of more than a thousand CVs, and only a few of them have a longer flight time. The authors of this study were able to find the closest orbit. A pair of stars need only 51 minutes to complete an elliptical path. There is a missing link in astronomy.
The study was published in the journal Nature. Kevin Burdge is a physicist at MIT. The stars in this study are thousands of light-years away.
“This one star looked like the Sun, but the Sun can’t fit into an orbit shorter than eight hours — what’s up here?”
Kevin Burdge, Department of Physics, MIT.
The stars are at the end of their stories. They have been companions for about eight billion years. The remnant of a main sequence star that went through a red giant phase is now a white dwarf. A Sun-like star is accompanying it on its way to becoming a red giant and a white dwarf. The pathway is being disrupted by the white dwarf.
Our Sun is about the same temperature as the donor star. It is only a tenth of the size of the Sun or about the size of Jupiter. The one star looked like the Sun, but it couldn't fit into an eight-hour time frame. Burdge was quoted in the release. The white dwarf is about half the size of the Sun and has a lot of packed material. There is a strange object.
None of this close together is what astronomer have discovered. The pair are very close to each other, but they are not visible to us. The researchers were given multiple opportunities to observe the eclipses.
The pair is called ZTF J1813+ A notable public-private partnership is engaged in an optical study of the northern sky looking for variable phenomena. The name doesn't matter. The particular stage the pair are in makes scientists pay attention.
The vampire star has been taking hydrogen away from the donor star, and it is starting to cannibalize it. One of these systems was caught in the act of changing from hydrogen to helium accretion.
The switch is a missing link in astrophysics and observing it is essential. There was no evidence of how the stars in the CVs switched from hydrogen to helium.
The evolution from hydrogen accretion to helium accretion was unknown before this study. The stars have never been observed making the transition. The observations of Z Task Force J1813 have changed that. The donor star is 100 times denser than the Sun, according to observations. The density shows that the white dwarf companion is not hydrogen-rich.
“This is a special system.”
Kevin Burdge, Department of Physics, MIT.
The scientists predicted decades ago that the stars would shrink until they were too short. The Sun-like star has a white dwarf consuming its hydrogen. The Sun-like star is no longer around. The star is kept in a tight circle by the heavy core.
There were many more observations of the stars. With more precise data, the researchers were able to perform more accurate simulations to see what would happen. The simulation results gave answers to questions about the variables.
The simulations show that in 70 million years the pair will be even closer. The CV will be a helium CV. The authors write that there is a previously missing link between the two.
The orange dotted line, red dotted line, and blue dotted line are different depending on when the donor star began to lose mass. The main sequence's orange, red, and blue colors are 98%, 98%, and 98%, respectively. There is a star on the red line. The evolutionary track for El Psc is shown in the purple line.
The simulation laid out an evolutionary path for the star. The donor star's temperature goes up as it tries to respond to mass loss. As the hydrogen is fused, the temperature goes down. The donor star's temperature drops due to expansion as the orbital period shrinks. There is a Helium CV at that point in time.
A minimum of 18 minutes is how long the star will last. The pair will be apart for about 30 minutes after that. The Y axis shows 100 million years.
The evolution of the donor star's mass can be seen in a few hundredths of a solar mass.
The donor loses its hydrogen when it becomes a CV. All of the star's hydrogen is lost at the minimum period.
Waves are a part of the study. Burdge has a special interest in astrophysical sources of radiation. The first measured giltational waves were in 2015, and they are an important area of study in astronomy. Gravitational waves allow us to study the universe in a completely different way.
The pair should emit waves close to each other. They have to be very close together to emit the waves, but not too close, at a distance of 10,000 km. It was debated for a long time if these objects could get short enough to emit ripples in the universe. Burdge said that the discovery puts that to rest.
Burdge and his colleagues were able to locate this pair. They looked for variables that flashed in an hour. That means that the stars cross each other's paths. The first thing they did was use an algorithm to look for stars. About one million stars were generated by that program. Burdge was looking through that selection.
He zeroed in on Z Task Force J1813+42. Burdge said that he saw an eclipse happen every 51 minutes.
Burdge said that the system was a special one. A system that answers a big open question is one of the most beautifully behaved cataclysmic variables known.
All Rights Reserved © 2024
