{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Notes covered in Exam2

Notes covered in Exam2 - Review Questions What are stars...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Review Questions: -- What are stars doing while on the main sequence? -- What are the 3 ranges of stellar mass relevant for stellar evolution? What is the end product of a high mass star? Or a low mass star? Why does the mass of the star determine its end fate (I.e. what physical processes are at work?) -- can you describe conceptually what happens in the interior of a low mass star like the sun once it evolves off the main sequence? How come it develops an “onion-like” layered structure in its core? -- What are the corresponding stages in the HR diagram? -- why is iron the end product of stellar evolution?
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
What is the Origin of Cosmic Rays? Astr 2340 Spring 2010 R. Chandar
Image of page 2
What is the origin of cosmic rays? Discovery of Cosmic Rays General properties of cosmic rays Cosmic rays from the Sun Accelerating Cosmic rays Detecting cosmic rays
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Types of Radiation We have discussed electromagnetic radiation, I.e. light – massless, travel at v=c When scientists first started studying radiation in the early 1900s, they found 3 different types of rays Alpha rays – turned out to be Helium nuclei (matter) Beta rays – turned out to be electrons and positrons (matter) Gamma rays – turned out to be light (not matter) Detectors invented to study radiation included Geiger counters, film and electroscopes
Image of page 4
Discovery of Cosmic Rays He was trying to find the source of additional radiation seen at ground level that could not be explained by natural sources of radioactive decay Viktor Hess (1912) takes electroscope on a Viktor Hess (1912) takes electroscope on a balloon flight to 17,500 feet (without balloon flight to 17,500 feet (without oxygen!) oxygen!)
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Hess’ Experiment Hess used an electroscope – detects charge on 2 thin films When the cosmic rays (charged particles) hit the electroscope, they carried away charge More cosmic rays electroscope would discharge faster Found that the number of cosmic rays increased above ~1 km, and concluded that these were coming from outer space and not the earth Hess won the Nobel prize in 1936 for his discovery of cosmic rays
Image of page 6
What are cosmic rays?
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern