1、Scientists discover Milky Ways youngest exploding star科学家们发现了银河系中已知的最年轻的超新星。相对于其它同伴来说，这颗年龄仅 140 岁的超新星就像一个婴儿。Scientists have announced the discovery of the youngest known exploding star, or supernova (超新星 ), in our Milky Way galaxy (银河系). Astronomers say the remnant (残骸 ) of the most recent supernova
2、 could provide clues to a long-standing mystery about why so few supernovae seem to explode in our galaxy, compared to other galaxies.Astronomers using NASAs Chandra X-ray Observatory and the Very Large Array radio telescope in New Mexico have discovered the remains of a supernova, known as “G1.9”,
3、which must have lit up our galaxy with a bright flash of light about 140 years ago.At a NASA news conference, scientists said they were able to estimate the age of the supernova by tracking its remnants rate of expansion (扩张) over the last 20 years. They said it expanded by 16 percent a surprisingly
4、 large amount indicating it is much younger than previously thought.The scientist who led the study, Stephen Reynolds of North Carolina State University, said radio and X-ray technology allowed scientists to track the dying star through a dense field of gas and dust that had previously obscured the
5、view.The second most recent supernova is believed to have occurred around 1680. Astronomers have been searching for more “missing” supernovae and their remnants. Reynolds explained that scientists had measured the rates of exploding stars in other galaxies, and found out that our own Milky Way galax
6、y seems to be lagging behind in the number of supernovae per century.Scientists said the discovery of the young remnant would be a “goldmine” to study, since it was still so recent and energetic. They said it was an important finding for understanding the life cycles of stars in the Milky Way galaxy
7、.Bob Kirshner of Harvard University explains why supernovae are important for all of us.“The supernovae make the chemical elements, transforming the light elements into the heavy ones,” he said. “So the calcium that is in your bones and the iron that is in your blood probably came from the supernovae that exploded before the sun formed. So it seems reasonable for us to want to know how these elements get formed when stars explode.”Supernovae and their remnants create the majority of the elements in the universe, spreading everything from cobalt (钴) to gold.
