An interdisciplinary group centered around a Jena astrophysicist utilized observations from antiquity to prove that Betelgeuse— the bright red huge star in the upper left of the constellation Orion— had been yellow-orange some 2, 500 years ago.
As nuclear blend in the center of the star progresses, brightness, size, and color also alter. Astrophysicists can derive through such properties important information to the age and mass of a star. Those stars along with significantly more mass than our own sun are blue-white or even red— the transition from red to yellow and orange is relatively rapid for astronomical time-scales.
Astrophysicists of Friedrich Schiller University Jena, Germany, along with colleagues of other subjects from the U. S. plus Italy, have now successfully discovered and dated such a color change in a bright star. With several historical resources, they found that Betelgeuse— the bright red large star in the upper still left of the constellation Orion— had been yellow-orange some 2, 000 years ago. They report about their results in the current concern of Monthly Updates of the Royal Astronomical Community .
Sources from antiquity from around the world
The Chinese court astronomer Sima Qian wrote about 100 BC about superstar colors: white is like Sirius, red like Antares, yellowish like Betelgeuse, blue like Bellatrix. “ From these specs, one can conclude that Betelgeuse at that time was in color between the blue-white Sirius and Bellatrix and the red Antares, ” says Prof. Ralph Neuhä user from the University associated with Jena.
Impartial from the above, the Roman scholar Hyginus described several 100 years later that Betelgeuse was in color like the yellow-orange Saturn— thus, one can quantify the former color of Betelgeuse along with even more precision.
Additional authors from antiquity like Ptolemy bring additional indications that Betelgeuse from their time did not belong to the group of bright reddish stars like Antares (in the constellation Scorpion) plus Aldebaran (in Taurus, the particular Bull).
The particular Greek name Antares means “ like Mars” in color; it was indeed reported as red and compared to Mars since millennia through cultures around the world. “ From a statement by the Danish astronomer Tycho Brahe, one can consider that, in the 16th centuries, Betelgeuse was more reddish colored than Aldebaran, ” Neuhä user notes. Today, Betelgeuse is comparable in brightness plus color to Antares.
Still 1 ) 5 million years to look until Betelgeuse explodes because supernova
Astronomer Ralph Neuhä user from Jena has integrated historical celestial observations in the astrophysical research for the past 10 years— this field is known as “ Terra-Astronomy. ” He closely collaborates with co-workers from languages, history, plus natural philosophy— including their wife Dagmar. “ The view back in time delivers solid impulses and important outcomes, ” Neuhä user adds. “ There are quite a number of astrophysical problems which can hardly end up being solved without historical observations. ”
What do those historical transmissions show about Betelgeuse? “ The actual fact that it changed in colour within two millennia from yellow-orange to red tells us, together with theoretical calculations, it has 14 times the particular mass of our sun— as well as the mass is the main unbekannte defining the evolution of stars, ” Neuhä consumer explains. “ Betelgeuse has become 14 million years old and in its late evolutionary phases. In about 1 . five million years, it will finally explode as supernova. ”