Astronomy Final Exam 4

A star that evolves off the main sequence in about 10 million years probably has

about 20 times the mass of our sun

the one-waving turning angle of a telescope mirror determines its

diffraction limit on its resolution

which of the following particles has the largest mass

neutron

in a HR diagram, the hottest stars are found

on the left side

which of the following magnitudes corresponds to the brightest star

+1.0

The distance modulus of a star at a distance of 10 parsecs would be

0

Our Sun is a G2V star with absolute magnitude 4.8. Suppose that a star of spectral type G2V is observed to have apparent magnitude 9.8. How far away is it?

1 parsec

the apparent brightness of our sun is roughly 1000 watts per square meter. Saturn is at roughly 10 astronomical units from our sun (slightly less actually). Viewed from Saturn, the apparent brightness of our sun would be

10 watts per square meter

compared to a magnitude 6 star, a magnitude 1 star would be

100 times as bright

A star is found to have absolute magnitude 4 and apparent magnitude 24. How far away is it?

100,000 parsecs

Suppose that a flash of lightning from a cloud 2500 meters away is followed by a clap of thunder two seconds later. Assume that the light arrived in a negligible time and calculate the speed of the sound waves.

1000 m/s

A star at a distance of 1000pc should have an apparent brightness equal to its absolute brightness multiplied by

10^-4

The star Vega is 25 parsecs from our Sun. The light from Vega has been traveling for about

80 years

which of the following star-like objects would most likely be considered to be a brown dwarf

Gliese 229B, luminosity and temperature both below type M9V

A star whose full spectral type is K2V is

a red main sequence star

in the HR diagram, a main sequence star would not be found

in the upper right or lower left

a star leaves the main sequence when

it runs out of hydrogen at its center

a hydrogen atom with its electron removed (a H+ ion in other words) is actually a

proton

a star with an apparent magnitude of 8.4 and an absolute magnitude of -1.0 would appear in our sky as a star

that is visible only with a telescope

When the core of a star collapses while inside the star, the result is a

type ii supernova