Examlex
Which is used observationally to determine the age of a star cluster?
Q20: The orbit of the Solar System around
Q24: The "guest star" observed by the Chinese
Q40: This diagram shows the period- luminosity relationship.
Q41: Why are dark dust clouds largely misnamed?<br>A)
Q42: Why do new stars generally form in
Q48: The spectra of interstellar gas clouds show
Q79: Why is it difficult to directly measure
Q93: If the Moon rises at sunset, then
Q115: Young open clusters contain a lot of
Q158: After reaching its peak luminosity in hours