Astronomers have long understood that a star called Thuban, possibly a North Star with the ancient Egyptians, is actually a pair of stars. NASA astronomers recently discovered that two stars overlap each other.
Recently, while hunting for signs of planets outside the universe, NASA's Transiting Exoplanet Survey (TESS) discovered a solar eclipse occurred in a pair of well-known stars aligned with the pyramid. Egypt.
The eclipse of a binary star is the phenomenon of a star crossing in front of the other star in the system and obscuring that star. The double star system is two stars with concentric orbits, when seen with the naked eye, it looks like a single star.
The double star system within the scope of TESS is Thuban, in fact consists of two stars: the big star is 4 times the size of the sun and 70% as hot as the sun with a temperature of about 9,704 C, the smaller star is 5 stars smaller times and only half as big.
The two stars orbit at an average distance of 60.8 million km with a full cycle of 51 days. Before that, their "eating" each other on their way is what astronomers have never discovered.
In a NASA statement, Angela Kochoska, a postdoctoral student at Villanova University, put the question "The first question that came to my mind was: How did we ignore this?"
"The short eclipse lasts only about 6 hours, so ground observations are easy to ignore. Because it is so bright, it quickly saturates the detectors on NASA's Kepler Observatory, which reveals the eclipse " is the answer that Kochoska presented at the annual meeting of the American Astronomical Association on Monday (January 6, 2020).
Astronomers now know that Thuban and its companions are among the most famous "solar eclipse stars" . In the case of a solar eclipse of the binary star system, the two stars never completely overlap, but only partially obscure our view.
Observing Thuban during authentic events could help astronomers get more accurate measurements of the mass and size of these pairs of stars.
According to Kochoska, it is expected that the TESS alien hunting machine will discover more eclipse phenomena in other parts of the sky as it continues to "scan" the universe.
The TESS space telescope is a two-year-old NASA space search mission led by the Massachusetts Institute of Technology. TESS tracks the night sky in 24º x 90º areas, each zone for 27 days.
Thuban is sandwiched between the bowl of the Little Dipper star array to the left and the handle of the Big Dipper (the name of the North Star's array of Western stars) to the right. We can easily find Thuban on a clear night (and it's hard to see when the sky is full of stars).
Thuban in the night sky.(Photo: NASA).
Thuban was once an ancient Arctic in ancient Egypt, building the first pyramids 4,700 years ago. At that time, Thuban is the axis that other stars orbit to shine at night. For this reason, the pyramids were built to face Thuban directly, according to some researchers.
The tilt and center of the Earth's axis changes over time, so the current North Star is Polaris , a brighter star on the right of Thuban.
One thing worth noting is that, by mistake, in Vietnam, some documents and many people still mistakenly call the North Star to the North Star . In fact , the Big Dipper or Big Spoon are the seven brightest stars in the Big Bear constellation (Great Bear or Ursa Major), while the North Star belongs to the Little Bear constellation (Little Bear or Ursa Minor). The Little Bear also has seven stars that form a spoon called the Small Spoon but is much dimmer and less known than the Big Spoon though these two spoons are also close together.
The position of Polaris, the current Arctic Star is at the end of the handle of the Little Spoon.
Polaris, Thuban, Big Spoon in Big Bear and Small Spoon in Big Bear (Image: EarthSky).