📖 what
What is a Cepheid variable star?
AstronomyVariable Stars
Quick Answer
A Cepheid variable is a star whose brightness changes in a regular pattern as it expands and contracts. Its pulsation period is directly related to its true luminosity.
The Full Story
Cepheid variables are crucial to astronomy because the period of their brightness changes tells astronomers how intrinsically bright they are. This period-luminosity relation was discovered by Henrietta Swan Leavitt in the early 20th century. By comparing true brightness with apparent brightness, astronomers can estimate distances to nearby galaxies. Cepheids have played a major role in establishing the scale of the Universe and calibrating the Hubble constant.
Key Facts
1.Henrietta Leavitt discovered the period-luminosity relation
2.Cepheids are key standard candles
3.They help measure distances to galaxies
YouTube Angle
Suggested video title for this topic:
"The blinking stars that help map the Universe"