As compared to Cepheids, RR Lyrae stars are...
* fainter and slower pulsating.
* brighter and faster pulsating.
* fainter and faster pulsating.
* brighter and slower pulsating.
To determine the answer, we need to compare the properties of Cepheids and RR Lyrae stars.
Cepheids and RR Lyrae stars are both types of variable stars, meaning their brightness fluctuates over time. However, they differ in several ways:
1. Brightness: Cepheids are generally brighter than RR Lyrae stars. Cepheids are often classified as either Classical Cepheids or Type II Cepheids, while RR Lyrae stars belong to the type called pulsating horizontal branch stars. Classical Cepheids are typically more luminous than RR Lyrae stars.
2. Pulsation Period: Cepheids have longer pulsation periods compared to RR Lyrae stars. Pulsation period refers to the time it takes for the star to complete one cycle of brightness variation. Cepheids typically have pulsation periods ranging from a few days to several weeks, while RR Lyrae stars have shorter pulsation periods, usually between 0.2 and 1 day.
Based on these comparisons, the correct answer is:
* Brighter and slower pulsating.
Cepheids are brighter and have longer pulsation periods compared to RR Lyrae stars, which are fainter and have shorter pulsation periods.