[Solved] Which of the Following Statements About Spectroscopic Binary Stars Is

Some "superstars" give off more than 50,000 times the energy of the Sun. Why are there no such stars among the stars that are close to the Sun? A) because conditions in the "neighborhood" of the Sun only permit low-mass (low luminosity) stars to form B) because such very luminous stars are extremely rare, and thus any small neighborhood in the Galaxy is unlikely to contain one of them C) because all stars in the vicinity of the Sun have planets, and planets rob a star of its brightness D) because such superstars only give off a lot of energy for a year or so, before they die E) because such superstars are really several hundred stars blending their light together (but so far away we can't distinguish individual stars); nearby stars are easy to separate

The most common kinds of stars in the Galaxy have A) low luminosity compared to the Sun B) spectra that show they contain mostly carbon C) enormous masses compared to the Sun D) diameters thousands of times greater than the Sun's E) a dozen or more stars in close orbit around them Section 18.2: Measuring Stellar Masses

Which of the following characteristics of a single star (one that moves through space alone) is it difficult to measure directly? A) its apparent brightness B) its temperature C) its chemical composition D) its mass E) you can't fool me, all of these are quite easy to measure directly

Two stars that are physically associated (move together through space) are called A) double stars B) main sequence stars C) brown dwarf pairs D) first contact stars E) binary stars

What was the first evidence that gravity outside our solar system worked the same way as it does inside? A) Galileo saw through his early telescope that the Milky Way consisted of many stars B) Herschel measured the two stars that make up the Castor system moved around each other C) Cannon measured different lines in the spectra of different types of stars D) Comet Halley returned after a 76-year absence E) You can't fool me, we still don't know whether gravity around other stars works the same way as it does here

I am measuring the spectrum of the stars in a spectroscopic binary system. When one of the stars is moving toward the Earth in its orbit, we observe A) that the lines in its spectrum get brighter B) that the lines in its spectrum merge with the lines of the other star C) that it is no longer possible to learn what elements are in the star D) that the lines in its spectrum show a blue-shift E) none of the above

Which law do astronomers use to determine the masses of the stars in a spectroscopic binary system? A) Wien's Law B) Kepler's Third Law C) Stefan-Boltzmann Law D) Hubble's Law E) Jenny Craig's Law

Stars that do not have what it takes to succeed as a star (i.e. do not have enough mass to fuse hydrogen into helium at their centers) are called: A) extras B) red giants C) spectroscopic stars D) brown dwarfs E) main sequence stars

Which of the following has the smallest mass? A) a brown dwarf B) a planet C) the Sun D) the smallest mass star that can still have fusion of hydrogen to helium in its core E) you can't fool me, all the above have roughly the same mass

Stars on the main sequence obey a mass-luminosity relation. According to this relation, A) the lower the mass, the higher the luminosity B) if you double the mass, you get double the luminosity C) luminosity is proportional to mass to the fourth power (luminosity increases strongly with mass) D) bright stars have more mass around them in the form of planets, comets, and asteroids E) the brightest stars are made of such light materials they hardly have any mass at all Section 18.3: Diameters of Stars