文章大意:这是一篇说明文。主要介绍了长期以来,天文学家一直认为,欧洲航天局盖亚卫星观测到的一个奇怪的恒星系统是一颗恒星围绕黑洞运行的简单例子。但两位天文学家正在挑战这一说法,他们发现证据表明了一些更奇怪的东西:一种从未见过的恒星,由看不见的暗物质组成。这个系统由一颗类似太阳的恒星和它神秘的暗物质伴星组成,后者的质量要大得多。
Astronomers long thought that an odd star system observed by the European Space Agency’s Gaia satellite was a simple case of a star orbiting a black hole. But two astronomers are challenging that claim, finding that the evidence suggests something far stranger: a never-before-seen type of star made of invisible dark matter. The system consists of a sun-like star, and its mysterious dark companion, which is much more massive.
What could that dark companion be? Maybe, as suggested, it’s a clump (团) of dark matter. Dark matter is an invisible form of matter that makes up the vast majority of the mass of every single galaxy (星系). We still don’t have a solid understanding of its identity. Most theoretical models assume that dark matter is smoothly distributed in each galaxy, but there are models that allow it to come together on itself.
One of these models supposes that dark matter in this case is a new kind of boson (玻色子). These bosons would have the ability to form clumps. Some of them could be the size of entire star systems, but some could be much smaller. The smallest ones could be as small as stars, and they get a new name: boson stars. Boson stars would be entirely invisible. Because dark matter doesn’t interact with other substances or light, we could detect them only through the gravitational influence on their surroundings. The researchers pointed out that a simple model of boson dark matter could produce enough boson stars to make the two astronomers’ finding reasonable.
While it’s unlikely that this is actually the discovery of a boson star, follow-up observations are still urged. Most importantly, this unique system gives us a rare opportunity to study the behaviour of strong gravity, allowing us to examine Einstein’s theory of general relativity to see if it holds. Secondly, if it is a boson star, this system is the perfect experimental set-up. We can keep studying our models of boson stars, see how well they can explain the orbital dynamics of this system and use that information to glimpse into the dark corners of the universe.
6. What does the evidence show about the odd star system?
A.Its mass is less than the sun. |
B.It is a simple case for astronomers. |
C.It is made of a star and a black hole. |
D.Its star is made of invisible dark matter. |
7. What can we infer about dark matter from paragraph 2?
A.It can be gathered. |
B.It is solid and inactive. |
C.It can be a clump of visible matter. |
D.It makes up a minority of the galaxy’s mass. |
8. What are boson stars?
A.The smallest dark matter. |
B.The smallest boson clumps. |
C.The smallest boson models. |
D.The smallest star systems. |
9. What does the author convey in the last paragraph?
A.Einstein’s theory holds true. |
B.Boson stars have been confirmed. |
C.More relevant studies will be needed. |
D.A perfect model contains a boson star. |