What important role do Cepheid variables stars have in astronomy?

The first suggestion that there were collections of stars beyond our Milky Way in the universe was made by

18.   Primary appraisal is the determination of resources available to manage a stressor or threat.

What is it that keeps localized regions of space, such as things on the Earth, planetary systems, star clusters, and whole galaxies, from participating in the general expansion of the universe?

Las celebraciones y emociones (Part 3) Match each word to the most logical related verb.

The Milky Way in which the Sun resides is an example of which type of galaxy?

35.  Emotional intelligence involves understanding one’s own emotional reactions and those of others and using this understanding to make good decisions.

To answer the following question, you will probably need to use special characters (¿ ñ ¡) and/or accent marks (á é í ó ú). In order to indicate that a letter has a special character or an accent mark, you will have to put that letter in parenthesis.For example:If your answer is: ¿De dónde es el profesor de español? Él es de Panamá.You will need to type: (?)De d(o)nde es el profesor de espa(n)ol? (E)l es de Panam(a). To receive credit, you must answer the question using a complete sentence in Spanish and you must also indicate if there are any special character or accent marks in your answer.   Now, answer the following question using a complete sentence in Spanish: ¿A qué hora se durmió usted anoche?

Approximately how far is the Sun from the center of our Galaxy?

What is it that makes the study of the structure of our own Galaxy more difficult than that of much more distant spiral galaxies?