- #1
Mooky
- 20
- 0
Hello,
I've read about this in four different textbooks and in several websites, but I still don't get it: how are Cepheids used to measure distances? I understand that Cepheids are stars whose brightness varies periodically; that the longer their period, the brighter they are; and that different Cepheids have different brightness and periods.
But, how is that used to measure distances?
Thanks,
M
I've read about this in four different textbooks and in several websites, but I still don't get it: how are Cepheids used to measure distances? I understand that Cepheids are stars whose brightness varies periodically; that the longer their period, the brighter they are; and that different Cepheids have different brightness and periods.
But, how is that used to measure distances?
Thanks,
M