Foundations of Astronomy (MindTap Course List)
14th Edition
ISBN: 9781337399920
Author: Michael A. Seeds, Dana Backman
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 9, Problem 17RQ
To determine
The spectral class, luminosity class, type and color of star.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
"51 Pegasi" is the name of the first normal star (besides the Sun) around which a planet was discovered. It is in the constellation Pegasus the horse. Its parallax is measured to be 0.064 arcsec.
a. What is its distance from us?
b. The apparent brightness is 1.79 × 10-10 J/(s·m2 ). What is the luminosity? How does that compare with that of the Sun? Look up the temperature: how do
. The spectrum of Star A peaks at 700 nm. The spectrum of Star B peaks at 470 nm. We know
nothing about what stage of stellar evolution either of these stars are in. Which of the
following are true?
A. Star A has a higher luminosity than Star B.
B. Star B has a higher luminosity than Star A.
C. Star A is cooler than Star B.
D. Not enough information to comment on their luminosities.
E. B and C
F. C and D
12.
A star with spectral type MO has a surface temperature of 3750 K and a radius of 0.63 Rsun: How many
times more luminous is this star than the Sun? (if it is less luminous enter a number less than one)
Answer:
Submit All Answers Last Answer: 0.0923
Incorrect, tries 1/5.
Hint: Use the Luminosity equation, which says that L is proportional to R^2 T^4. If you keep these as
ratios compared to the sun, your L will also come out as a ratio compared to the Sun.
This star has a mass of 0.4 Msun- Using the simple approximation that we made in class, what is the
main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr.
Answer:
Submit All Answers
Compare this to the lifetime of a MO star listed in Table 22.1 (computed using a more sophisticated
approach). Is the value you calculated in the previous problem longer or shorter than what is reported
in the table? (L for longer, S for shorter) (You only get one try at this problem.)
Answer:
Submit All Answers
Chapter 9 Solutions
Foundations of Astronomy (MindTap Course List)
Ch. 9 - Prob. 1RQCh. 9 - Why was the Hipparcos satellite able to make more...Ch. 9 - Prob. 3RQCh. 9 - Prob. 4RQCh. 9 - Prob. 5RQCh. 9 - Prob. 6RQCh. 9 - Prob. 7RQCh. 9 - Prob. 8RQCh. 9 - Prob. 9RQCh. 9 - Prob. 10RQ
Ch. 9 - Prob. 11RQCh. 9 - Prob. 12RQCh. 9 - Prob. 13RQCh. 9 - Prob. 14RQCh. 9 - Prob. 15RQCh. 9 - Prob. 16RQCh. 9 - Prob. 17RQCh. 9 - Prob. 18RQCh. 9 - Prob. 19RQCh. 9 - Prob. 20RQCh. 9 - Prob. 21RQCh. 9 - Prob. 22RQCh. 9 - Prob. 23RQCh. 9 - Prob. 24RQCh. 9 - Prob. 25RQCh. 9 - Prob. 26RQCh. 9 - Prob. 27RQCh. 9 - Prob. 28RQCh. 9 - Prob. 29RQCh. 9 - Prob. 30RQCh. 9 - Prob. 31RQCh. 9 - Prob. 32RQCh. 9 - How Do We Know? In what way are basic scientific...Ch. 9 - Prob. 1PCh. 9 - Prob. 2PCh. 9 - Prob. 3PCh. 9 - Prob. 4PCh. 9 - Complete the following table:Ch. 9 - Prob. 6PCh. 9 - Prob. 7PCh. 9 - Prob. 8PCh. 9 - Prob. 9PCh. 9 - Prob. 10PCh. 9 - Prob. 11PCh. 9 - Prob. 12PCh. 9 - Prob. 13PCh. 9 - Prob. 14PCh. 9 - Prob. 15PCh. 9 - Prob. 16PCh. 9 - Prob. 17PCh. 9 - Prob. 18PCh. 9 - Prob. 19PCh. 9 - Prob. 20PCh. 9 - Prob. 1SOPCh. 9 - Prob. 2SOPCh. 9 - Prob. 3SOPCh. 9 - Look at the image on the opening page of this...Ch. 9 - Prob. 2LTLCh. 9 - Prob. 3LTLCh. 9 - Prob. 4LTL
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Assume that an O main-sequence star (40,000 K) and a G main-sequence star (5,500 K) have the same radius. How many times brighter is the O star? LO LG = Star B is located 2.6 times farther from earth than Star A, but both have the same apparent visual magnitude of 1 mag. Which star is intrinsically brighter?How many times brighter is the star? If a star has an apparent magnitude equal to its absolute magnitude, how far away is it in parsecs? pcarrow_forwardSuppose a star has a luminosity of 7.0x1026 watts and an apparent brightness of 4.0x10-12 watt/m?. How far away is it? Give your answer in both kilometers and light-years.arrow_forwardChoose the statements that correctly describe the characteristics of the stars located in the labeled quadrants of the H-R diagram. Luminosityarrow_forwardEach choice below lists a spectral type and luminosity class for a star. Which one is a hot main sequence star? OA. spectral type 09, luminosity class I O B. spectral type 01, luminosity class V O C. spectral type M2, luminosity class I OD. spectral type M2, luminosity class Varrow_forwardIf the stars Betelgeuse and Rigel each have the same luminosity, but the temperature of Betelgeuse is lower than Rigel, which star has the greater surface area? O A. Betelgeuse B. Rigel O C. They are the same size. OD. There is insufficient information to answer this question.arrow_forward12: A star with spectral type A0 has a surface temperature of 9600 K and a radius of 2.2 RSun. How many times more luminous is this star than the Sun? (if it is less luminous enter a number less than one) Answer: 36.854 13:This star has a mass of 3.3 MSun. what is the main sequence lifetime of this star? You may assume that the lifetime of the sun is 1010 yr. Please answer question 13 thank you.arrow_forwardStar 1 and star 2 have the same V-magnitude, V = 7.5. However, they have different B-magnitudes, B1 = 7.2 and B2 = 8.5. If star 2 has a distance that is 10 times further than star 1, what are the luminosity ratios, L1/L2, in both B- and V-bands?arrow_forwardThe sketch below shows an H-R diagram for a star cluster. Consider the star to which the arrow points. How is it currently generating energy? Temperature A. by hydrogen shell burning around an inert helium core B. by gravitational contraction C. by core hydrogen fusion D.by core helium fusion combined with hydrogen shell burning E. by both hydrogen and helium shell burning around an inert carbon core Luminosity -→arrow_forwardWhich of the following binary star systems cannot exist? A. A 1 solar-mass main sequence star and a 4 solar mass red giant with a size 100 times smaller than the orbital distance. B. A 15 solar-mass main sequence star and a 10 solar mass red giant with a size 100 times smaller than the orbital distance. C. A 1 solar-mass main sequence star and a 4 solar-mass main sequence star. D. A 2 solar-mass main sequence star and a 1 solar mass red giant with a size a few times smaller than the orbital distance.arrow_forwardChoose the correct statements concerning spectral classes of stars. (Give ALL correct answers, i.e., B, AC, BCD...) A) Neutral hydrogen lines dominate the spectrum for stars with temperatures around 10,000 K because a lot of the hydrogen is in the n=2 level. B) Hydrogen lines are weak in type O-stars because most of it is completely ionized. C) Oh Be A Fine Guy/Girl Kiss Me, is a mnemonic for remembering spectral classes. D) The spectral sequence has recently been expanded to include L, T, and Y classes. E) K-stars are dominated by lines from ionized helium because they are so hot. F) The spectral types of stars arise primarily as a result of differences in temperature.arrow_forwardIf a star has a surface temperature of 3000 K but a luminosity 150 times greater than our Sun, what size is this star? Give your answer in units of the solar radius, R .arrow_forwardThe spectral type of a star is directly related to its color. Recall that a star emits light as a blackbody, which has a particular shape to its spectrum, as shown in this figure. Based on this, what basic property of a star determines its color (and thus its spectral type)? Choose one: A. age B. composition C. radius D. temperaturearrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
Recommended textbooks for you
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning