3.5 Astro 1 Section 1 Professor Brandt

3.5 Astro 1 Section 1 Professor Brandt - Astro 1 Section 1...

Info icon This preview shows pages 1–2. Sign up to view the full content.

Astro 1 Section 1 Professor Brandt Friday March 5th 1999 Announcements: Lecture notes: Class 24 As usual it is very important to be able to measure distances on very large scales - recurring problem for astronomers. We have talked about several methods astronomers use to measure distances to cosmic objects. - parallax - spectroscopic parallax - RR Lyrae variable stars - Cepheid variable stars However not even Cepheid variable stars can be used to probe quite distant galaxies. Even with HST Cepheid variables can only be used to about 15 Mpc - not bright enough. For comparison the most distant quasar known has a distance of about 40 000 Mpc. Makes it clear we need other methods. Again we rely on standard methods. Need luminosity and apparent brightness to get distance. - P-L relation gave us Cepheid L and let us make progress. - We rely on other tricks for even larger distances. - can figure out brightest globular clusters in nearby galaxies and compare to more distant ones. Globular clusters are quite luminous so
Image of page 1

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

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '99
  • Brandt
  • Astronomy, Globular cluster, Cepheid variable, distant galaxies

{[ 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