In 1912, after studying a star cloud called the Small Magellanic Cloud, Henrietta Leavitt concluded that:
A) stars are eternal and unchanging.
B) the brightest stars have the shortest pulsation periods.
C) the Sun and Earth are near the edge of our Galaxy.
D) there was a relationship between pulsation periods and luminosities of stars.
D
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The elements that we are all made of are common everywhere in the observable Universe
a. True b. False Indicate whether the statement is true or false
Significant Figures: Express the result of the following calculation to the proper number of significant figures: 50.19 - 7966 × 10-3.
Fill in the blank(s) with the appropriate word(s).
In a photo like the Hubble Deep Field (Figure 20.1 in your textbook), we see galaxies in many different stages of their lives. In general, which galaxies are seen in the earliest (youngest) stages of their lives?
A) the galaxies that are farthest away B) the galaxies that have the most hot, young O and B stars C) the galaxies that are the reddest in color D) the galaxies that are nearest to us
Conversion of Units: There are 2.00 dry pints to 1.00 dry quart, 8.00 dry quarts to 1.00 peck, 4.00 pecks to 1.00 bushel. An organic farmer wants to pick enough berries to fill 40,000 pint containers. How many bushels of berries does the farmer need?
Fill in the blank(s) with the appropriate word(s).