天文学导论报告.docx

1、第13章第56題Go to the European Space Agencys Gaia (Global Astrometric Interferometer for Astrophysics) mission website (/science/gaia). Has Gaia been launched? How will it help astronomers determine the distances to more stars? Why will it map the stars from an L2 orbit (see Connections 4.2)?回答：Gaia has been launched.Gaia will create an extraordinarily precise three-dimensional map of more than a thousand million stars throughout our Galaxy and beyond by mapping their motions, luminosity, temperature and composition in order to help astronomers determine the distances to more stars.Because It offers a clearer view of the cosmos than an orbit around Earth, which would result in the spacecraft passing in and out of Earths shadow and causing it to heat up and cool down, distorting its view. Free from this restriction and far away from the heat radiated by Earth, L2 provides a much more stable viewpoint.对本网络资源的学习与研究总结：I learned something about the Gaia. This website introduces the objective, mission, spacecraft, journey, history and some features about Gaia.2、第13章第57題GototheEclipsingBinaryStarsLabwebsiteat/naap/ebs/ebs.html. Click on “Eclipsing Binary Simulator.” Select preset Example 1, in which the two stars are identical. The animation will run with inclination 90 and show a 50 percent eclipse. What happens when you slowly change your viewing angle to the systemthe inclination; how does this change the eclipse? At what value of inclination do you no longer see eclipses? What does the system look like at 0? Reset the inclination to 90 and adjust the separationof the two stars. How does the light curve change when the separation is larger or smaller? Now make the two stars different. Change star 2 so that its radius is 3.0 R and its temperature is 4000 K. At what value of inclination do you no longer see eclipses? What types of eclipsing binary systems do you think are the easiest to detect?回答：When I slowly change the inclination, the eclipse decrease. I no longer see the eclipses at 70 degree of inclination. The system looks like a circle at 0 degree. When the separation is larger, the interval of eclipse becomes shorter and the light curve becomes steeper. When the separation is smaller, the interval of eclipse becomes longer and the light curve becomes gentler. I no longer see eclipses at 48 degree. The binary systems with high temperature, small separation and inclination of 90 degrees are the easiest to detect.对本网络资源的学习与研究总结：This website offers a Eclipsing Binary Simulator. In this simulator, we can set the mass, temperature, radius, separation, inclination of the binary system. Then the simulator will simulate the perspective from earth and the light curve. In this way, we can realize how the binary systems influence the eclipse easily.3、第15章第56題Go to the Astronomy Picture of the Day (APOD) website(/apod), do a search on “molecular clouds,” and pick out a few images. Were these pictures obtained from space or on the ground, and at what wavelengths? With which telescopes? What wavelengths do the colors in the images represent? Are they “real” or “false-color” images? Explain your answers.This pictures was obtained from space at visible wavelengths by Hubble Space telescope. The colors in the images represent the visible wavelengths and they are real-color. The camera took the photos of the molecular cloud in three basic colors and synthesis them into a real-color image, as is shown above.This pictures was obtained from space at inferred wavelengths by Hubble Space telescope. The colors in the images represent the inferred wavelengths and they are false-color.对本网络资源的学习与研究总结：This website provides lot of high-quality and brilliant images of universe and detailed information of each image. I learned how these pictures were taken.4、第15章第59題Go to the website for Stardust(), a Citizen Science project that asks Internet users to use a virtual microscope to analyze digital scans of particles collected by the Stardust mission in 2006. The goal is to identify tiny interstellar dust grains. Follow the four steps under “Get Started” (you need to create a log-in account) and help search for stardust. Click on “News.” What has been learned from this project. Remember to save the images for your homework, if required. 回答：I chose the foils to work on. What I have learned: When a hypervelocity particle hits the aluminum foil, a crater which is several times diameter of the particle is produced. People use electron microscopes instead of light microscopes to take photos of these foils. Although the particles stop quickly, many atoms of the particle remains and gives the information of the morphology and structure of the particle. In this stardust search, i have to find the craters in the images. Dark spots without bright rims are just holes in the foil and bright white spots without dark center are just surface contaminants. What I need to find are dark spots with bright rims.对本网络资源的学习与研究总结：This website asks volunteers from all over the world to find tiny particles by using two method ( aerogel and foils) in order to save the scientists and lab technicians time. I have to register fist. Then read a short tutorial to learn how to find the craters. And I must pass a test. Finally I can begin to find the craters among many images.五、觀星報告：在课程统一安排的观星活动中，我观测了木星和月球还有土星，是在天文台和路边天文分别观测了这些天体。在看木星的不同时间，能够