**PHY 445/515 The Cepheid Period-Luminosity Relation**

Compare this to the star's measured brightness to find the distance. The name Cepheid variable comes from the prototype star for which this was discovered, Delta Cephei. This star in the constellation of Cepheus the King varies between magnitude 3.5 and 4.3 over the course of five and a half days.... And distance from the earth to the cepheid variable star = R then F=L / ( 4 * pi * R^2 ) From this equation we can determine the distance of the cepheid variable star.

**PHY 445/515 The Cepheid Period-Luminosity Relation**

To find the distance of a Cepheid Let us use the Cepheid method to find the distance of a star cluster. Suppose we have observed a Population 1 Cepheid in the cluster with a period of 11 days and average apparent magnitude of 2.3.... Figure 7: The Cepheid period-luminosity relation The importance of such a relation, once it is calibrated, is that it provides a simple way to determine the distance to a Cepheid variable and, hence, to the cluster or galaxy that contains it.

**Cepheid Variable Stars Cosmic Distance Ladder - NAAP**

9/11/2014 · You detect a Cepheid in galaxy A that has a pulsation period of 3 days. You happen to know that the distance of galaxy A is 3 million light years. how to find someone on facebook without knowing their name Cepheid variable, one of a class of variable stars whose periods (i.e., the time for one cycle) of variation are closely related to their luminosity and that are therefore useful in measuring interstellar and intergalactic distances.

**astrophysics How to use parallax and Cepheids together**

It has been found that the period of the Cepheid variable is related to its intrinsic brightness, such that if one measures how often the star changes luminosity, one can calculate its intrinsic luminosity, thus allowing the distance to the Cepheid variable to be calculated. Another commonly used "Standard Candle" is a type of supernova, called a Type Ia supernova, caused by the collapse of a how to find the business object for a uibb The period/luminosity relationship of a Cepheid means that we can use it as a kind of cosmic yardstick. If we find a Cepheid, and measure the period of its fluctuations, and can measure how bright it appears from earth, then we can tell how luminous it really is, and from that calculate its distance.

## How long can it take?

### Cosmic distance ladder Wikipedia

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- How do Cepheid variable stars help in determining
- Finding the Pulsar Period and the Distance to the Cepheid
- Calculating distance with Cepheid variable stars

## How To Find Distance Of A Cepheid

29/05/2012 · Name two methods that could be used to find the distance to the nearest... show more Hey Guys! A bit of help please? :) I know how they can be used to measure distances to other galaxies, but the question is 'Before scientists used the Cepheid Variable method, the distance to the nearest Cepheid Star had to be found.

- The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are "close enough" (within about a thousand parsecs ) to Earth.
- Supernovae. At large distances (up to about 1 billion light-years), astronomers can no longer use methods such as parallax or Cepheid variables.
- A supporting idea for distance measurement is that if a specific kind of light source is known to have a constant and dependable absolute luminosity, then the measured intensity at the detector can be used to calculate its distance.
- Once Edwin Hubble had identified Cepheid variables in Andromeda galaxy, he could use the Period-Luminosity Relationship, discovered by Henrietta Levitt, to find the brightnesses of the stars. With that, and the inverse square law, he could measure the distance to the Andromeda galaxy, and to other galaxies in which Cepheid variables occurred.