The distances between objects in our galaxy are so great that astronomers have to wait months or years to observe how stars, planets, and other objects move around each other. often have to. But recently, astrophysicists at Northwestern University and the University of California, San Diego (UC San Diego) saw the light from a pair of ultracold dwarfs change within minutes. This led to the discovery that what was once thought to be one star was actually two. What’s more, the two stars were found to be so close to each other that they orbited each other in less than a day on Earth, setting the record for the densest ultracold binary system yet observed. I broke it.
Ultracold dwarfs emit most of their energy in the infrared spectrum, making them difficult to see with the human eye. In other words, it doesn’t burn bright enough to emit visible light to the naked eye. Still, they are very common in space, and astronomers can observe them with specialized tools.
Chie-Chun “Dino” Su, a postdoctoral fellow in physics and astronomy at Northwestern University’s Weinberg College of Arts and Sciences, said training such a tool in modern star systems, in the form of telescopes at the WM Keck Observatory in Hawaii. decided. Known as LP 413-53AB. He did so after using an algorithm he developed to analyze archived data on light emitted from various systems. His analysis showed that in one measurement the spectral lines created by the light from the two stars overlapped, while in another the lines diverged. The first measurement leads the observer to believe that LP 413-53AB is just a star. The second means there are two people.
Sure enough, Sue was able to see the shift for himself thanks to his own observations of the star system located in Taurus.
“When we were doing this measurement, we could see things change in just a few minutes of observation,” said Adam Burgasser, adviser to Hsu. “Most of the binary stars we track have orbital periods that span many years, so we get measurements every few months. After a while, we can put the puzzle together. With this system, we were able to see the spectral lines moving apart in real time.It’s amazing to see something happening in space on a human timescale.”
Hsu determined the distance between the two dwarfs to be about 1 million kilometers (about 621,370 miles), placing them much closer than the distance between Jupiter and its moon Callisto. Put another way, the space between the stars is only 1% of the space between the Earth and the Sun. The companion stars are so close together that they take only 20.5 hours to orbit each other, making her year on each star shorter than his one day on Earth time.
This is the fourth ultracold dwarf binary star system discovered by astronomers. In addition to having the shortest period of all others, LP 413-53AB is by far the oldest, recording billions of years compared to about 40 million years for other systems. There was also hope that previous binary dwarf systems would have habitable planets around them, but that won’t be the case with LP 413-53AB because the planets are too close to the star’s surface to support life. says Su.
“These ultracold dwarfs are our Sun’s neighbors,” Su said. “To identify potentially habitable hosts, it’s helpful to start with nearby neighbors. But if close binaries are common among ultracold dwarfs, few habitable worlds may be found.” I can’t.”
Alien life aside, Hsu’s algorithm gives researchers a new tool to search for other ultracold dwarfs found in historically hard-to-find binary star systems.
“These systems are rare,” says study co-author Chris Theissen, president and postdoctoral fellow at the University of California, San Diego. “But I don’t know if it’s rare because it’s rarely there, or if it’s rare because it’s just not found. It’s an open-ended question. Now we have one data point that we can start building This data has been in the archives for a long time, and Dino’s tools allow us to find more such binaries.”
Findings on LP 413-53AB were presented on January 10 at the 241st Annual Meeting of the American Astronomical Society in Seattle, Washington.
Source: Northwestern University
