Question

ASTRONOMY

1. As a dense gas core collapses down into a protostar, it shrinks from 10,000AU to 100 AU. Let's assume that angular momentum was conserved and that the protostars rotation period is 100 years. what was the rotation period of the dense core?

A. 1 year B. 10 years C. 100 years D.10^4 years E.10^6 years.

2. If star A is 5 times closer than star B and they have the same intrinsic luminosity, then the apparent luminosity of star A will be/

A. 5X smaller B. 25X smaller C. 5X bigger D. 25X bigger E. It depends on the star's magnitude

3. Cepheid variable stars Type Ia supernova are examples of "standard candles", meaning that we can infer?

A. their luminosities independently of their apparent brightnesses

B. their temperatures independently of their spectra

C. their ages independently of their luminosities

D. their sizes independently of their temperatures

E. their apparent brightnesses independently of their colors

Answer 1