Exam 13: Taking the Measure of Stars

Along the main sequence, how do the luminosity, temperature, radius, and mass of stars change as you go from the upper-left to the lower-right corners of the H-R diagram?

Eclipsing binary systems

What spectral class is the Sun?

The star named Capella has an apparent magnitude of 0, while the star named Polaris has an apparent magnitude of 2.This means that Capella appears ________ in our sky than Polaris.

The spectral class of a star is related to its

Parallax is used to measure a star's

Which stars show the largest amount of absorption from molecules such as TiO and CN?

Suppose you take a spectrum of a orange star and, based on the shape of its blackbody curve as well as its absorption lines, that it is of spectral type K3.However, you do not know its distance.How, then, can you determine whether it is a main-sequence star or a giant star?

The Hertzsprung-Russell diagram is a graph of ________ for stars.

If one star appears brighter than another in the night sky, then the brighter star

Based on the mass-luminosity diagram for main-sequence stars shown in the figure below, approximately how many more times luminous is a 25 M_SUN star compared with a 0.3 M_SUN star?

What property of light allows astronomers to measure the motions of spectroscopic binary stars?

If a star's parallax is measured using identical telescopes, one on Earth and the other on Mars, which planet's telescope would measure the bigger parallax? Explain your answer.

The habitable zone of a star is the region around that star where

The figure below shows an H-R diagram, with five stars labeled A through E.Which star has the smallest radius?

The blackbody spectra of a star with a temperature of 6000 K and a star with a temperature of 4000 K are shown in the figure below.An astronomer uses a telescope to observe each of these two stars in both the blue and red filters.The blue filter is centered at 450 nm, while the red filter is centered at 660 nm.For each of the two stars, indicate through which filter that star will be brighter.Explain your answer.

Astronomers can measure the speed of the stars in a binary system by measuring the ________ of the stars.

The stars that have the largest radii are classified as

Rigel is a star with an apparent magnitude of +0.1, and Betelgeuse is a star with an apparent magnitude of +0.4.Which star appears brighter, and what is the ratio of their brightness?

A star with a stellar parallax of 0.025 arcsecond has a distance of how many parsecs?