Exam 10: Characterizing Stars

Suppose we observe the light curve of a totally eclipsing binary like that in Figure 10-13 in Comins,Discovering the Essential Universe,6th ed.The brightness falls gradually from magnitude 5 to magnitude 9 and remains there for 12 hours before increasing gradually to magnitude 5.Then after a while it drops gradually to magnitude 6,remains there for 8 hours,and returns to magnitude 5.What conclusion can be drawn from this light curve?

Barnard's star,one of Earth's near neighbors,is classified as M5 V.This means that it is a:

What is a white dwarf star?

Which statement is NOT true about the center of mass of a binary star system?

Sirius,in Canis Major (the large hunting dog of Orion),is the brightest star in the winter night sky.It has a parallax angle of 0.38 seconds of arc.The brightest star in Orion's other hunting dog,Canis Minor,is Procyon,with a parallax angle of 0.29 seconds of arc.Vega,in Lyra,the Lyre (Harp),is the brightest star in the summer night sky.It has a parallax angle of 0.13 seconds of arc.Which of these stars is farthest away?

To determine the sum of the masses of a visual binary star system,what needs to be measured?

The intensity of sunlight per square meter reaching Jupiter is approximately what fraction of that at Earth's orbital distance? (For orbital radii,see Appendix,Table C-1,Comins,Discovering the Essential Universe,6th ed.)

What is the intensity of sunlight per square meter reaching Venus compared with this intensity at Earth's orbital distance? (For orbital radii,see Appendix,Table C-1,Comins,Discovering the Essential Universe,6th ed.)

Two stars have the same spectral classification,but it is observed that one of them has narrower spectral lines than the other.The star with the narrower spectral lines is:

In the case where a large number of stars of different masses all form at the same time (e.g.,in a cluster of stars),what does the phrase initial mass function mean?

For Balmer series lines to show up strongly in absorption in stellar spectra,significant numbers of hydrogen atoms have to have electrons in the n = 2 energy level.What then does the appearance of these lines in a stellar spectrum tell us about the temperature of the star's surface?

For a pair of stars to be classified as an optical double,which condition must be TRUE?

Which statement characterizes the human study of stellar evolution?

Using the Hertzsprung-Russell diagram (Figure 10-7 of Comins,Discovering the Essential Universe,6th ed.),determine which type of star has the following characteristics: surface temperature 10,000 K,luminosity 1/100 times that of the Sun.

From its position in the Hertzsprung-Russell diagram in Figure 10-7 of Comins,Discovering the Essential Universe,6th ed.,what can you conclude about the star Mira compared with the Sun?

Which spectral luminosity class corresponds to a red supergiant?

Fe XII is an ionized iron atom with:

What condition is necessary to see from Earth eclipses of stars in binary star systems?

The Sun has an absolute magnitude of +4.8.How far away would we have to be for the Sun to be just barely visible to the unaided eye (sixth magnitude)?

A star shows weak hydrogen Balmer lines but strong lines of neutral sodium.Which is a likely explanation for this phenomenon?