Astronomy
1st Edition
ISBN: 9781938168284
Author: Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher: OpenStax
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 22, Problem 30E
Suppose an astronomer known for joking around told you she had found a type-O main-sequence star in our Milky Way Galaxy that contained no elements heavier than helium. Would you believe her? Why?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
For a main sequence star with luminosity L, how many kilograms of hydrogen is being converted into helium per second? Use the formula that you derive to estimate the mass of hydrogen atoms that are converted into helium in the interior of the sun (LSun = 3.9 x 1026 W).
(Note: the mass of a hydrogen atom is 1 mproton and the mass of a helium atom is 3.97 mproton. You need four hydrogen nuclei to form one helium nucleus.)
Question 41
.Suppose you are looking at H-R diagrams of two similar star clusters. The most luminous main
sequence stars in the Porcini cluster are much more luminous than the most luminous main
sequence stars in the Morel cluster. What can you conclude?
O the Porcini cluster is younger than the Morel cluster
O the Porcini cluster is farther away than the Morel cluster
O the Porcini cluster is lower in metallicity than the Morel cluster
O the Porcini cluster is larger in diameter than the Morel cluster
As a cluster of stars begins to age, which type of star in the cluster will move off the main sequence of the H-R diagram first?
1)
all the stars in a cluster are born at the same time; so they will all move off the main sequence at the same time, as they evolve
2)
G type stars, like our Sun
3)
M type stars, which are the coolest
4)
the lowest mass stars, which have the least amount of fuel for fusion
5)
the O and B type stars
Chapter 22 Solutions
Astronomy
Ch. 22 - Compare the following stages in the lives of a...Ch. 22 - What is the first event that happens to a star...Ch. 22 - Astronomers find that 90% of the stars observed in...Ch. 22 - Describe the evolution of a star with a mass...Ch. 22 - Describe the evolution of a star with a mass...Ch. 22 - A star is often described as “moving” on an HR...Ch. 22 - On which edge of the main sequence band on an HR...Ch. 22 - How do stars typically “move” through the main...Ch. 22 - Certain stars, like Betelgeuse, have a lower...Ch. 22 - Gravity always tries to collapse the mass of a...
Ch. 22 - Why are star clusters so useful for astronomers...Ch. 22 - Would the Sun more likely have been a member of a...Ch. 22 - Suppose you were handed two HR diagrams for two...Ch. 22 - Referring to the HR diagrams in Exercise 22.13,...Ch. 22 - The nuclear process for fusing helium into carbon...Ch. 22 - Pictures of various planetary nebulae show a...Ch. 22 - Describe the two “recycling” mechanisms that are...Ch. 22 - In which of these star groups would you mostly...Ch. 22 - Explain how an HR diagram of the stars in a...Ch. 22 - Where did the carbon atoms in the trunk of a tree...Ch. 22 - What is a planetary nebula? Will we have one...Ch. 22 - Is the Sun on the zero-age main sequence? Explain...Ch. 22 - How are planetary nebulae comparable to a...Ch. 22 - Which of the planets in our solar system have...Ch. 22 - Would you expect to find an earthlike planet (with...Ch. 22 - In the HR diagrams for some young clusters, stars...Ch. 22 - If the Sun were a member of the cluster NGC 2264,...Ch. 22 - If all the stars in a cluster have nearly the same...Ch. 22 - Suppose a star cluster were at such a large...Ch. 22 - Suppose an astronomer known for joking around told...Ch. 22 - Stars that have masses approximately 0.8 times the...Ch. 22 - Automobiles are often used as an analogy to help...Ch. 22 - The text says a star does not change its mass very...Ch. 22 - The text explains that massive stars have shorter...Ch. 22 - You can use the equation in Exercise 22.34 to...Ch. 22 - You can estimate the age of the planetary nebula...Ch. 22 - If star A has a core temperature T, and star B has...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Explain all answers clearly, with complete sentences and proper essay structure, if needed. An asterisk (*) des...
Cosmic Perspective Fundamentals
4. Inside the earth and the sun. (a) Geophysicists have estimated that the temperature at the center of the ear...
College Physics (10th Edition)
29.2 In a physics laboratory experiment, a coil with 200 turns enclosing an area of 12cm2 is rotated in 0.040 s...
University Physics with Modern Physics (14th Edition)
The pV-diagram of the Carnot cycle.
Sears And Zemansky's University Physics With Modern Physics
A ball rebounds elastically from the floor. What doesthis situation share with the ideas of momentum conservati...
Modern Physics
25. FIGURE EX4.25 shows the angular-velocity-versus-time graph for a particle moving in a circle, starting from...
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
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
- According to the text, a star must be hotter than about 25,000 K to produce an H II region. Both the hottest white dwarfs and main-sequence O stars have temperatures hotter than 25,000 K. Which type of star can ionize more hydrogen? Why?arrow_forwardConsider the following five kinds of objects: open cluster, giant molecular cloud, globular cluster, group of O and B stars, and planetary nebulae. A. Which occur only in spiral arms? B. Which occur only in the parts of the Galaxy other than the spiral arms? C. Which are thought to be very young? D. Which are thought to be very old? E. Which have the hottest stars?arrow_forwardDescribe the evolution of a star with a mass similar to that of the Sun, from the protostar stage to the time it first becomes a red giant. Give the description in words and then sketch the evolution on an HR diagram.arrow_forward
- You can use the equation in Exercise 22.34 to estimate the approximate ages of the clusters in Figure 22.10, Figure 22.12, and Figure 22.13. Use the information in the figures to determine the luminosity of the most massive star still on the main sequence. Now use the data in Table 18.3 to estimate the mass of this star. Then calculate the age of the cluster. This method is similar to the procedure used by astronomers to obtain the ages of clusters, except that they use actual data and model calculations rather than simply making estimates from a drawing. How do your ages compare with the ages in the text? Figure 22.10 NGC 2264 HR Diagram. Compare this HR diagram to that in Figure 22.8; although the points scatter a bit more here, the theoretical and observational diagrams are remarkably, and satisfyingly, similar. Figure 22.12 Cluster M41. (a) Cluster M41 is older than NGC 2264 (see Figure 22.10) and contains several red giants. Some of its more massive stars are no longer close to the zero-age main sequence (red line). (b) This ground-based photograph shows the open cluster M41. Note that it contains several orange-color stars. These are stars that have exhausted hydrogen in their centers, and have swelled up to become red giants. (credit b: modification of work by NOAO/AURA/NSF) Figure 22.13 HR Diagram for an Older Cluster. We see the HR diagram for a hypothetical older cluster at an age of 4.24 billion years. Note that most of the stars on the upper part of the main sequence have turned off toward the red-giant region. And the most massive stars in the cluster have already died and are no longer on the diagram. Characteristics of Main-Sequence Starsarrow_forwardIn the HR diagrams for some young clusters, stars of both very low and very high luminosity are off to the right of the main sequence, whereas those of intermediate luminosity are on the main sequence. Can you offer an explanation for that? Sketch an HR diagram for such a cluster.arrow_forwardH II regions can exist only if there is a nearby star hot enough to ionize hydrogen. Hydrogen is ionized only by radiation with wavelengths shorter than 91.2 nm. What is the temperature of a star that emits its maximum energy at 91.2 nm? (Use Wien’s law from Radiation and Spectra.) Based on this result, what are the spectral types of those stars likely to provide enough energy to produce H II regions?arrow_forward
- If a 100 solar mass star were to have a luminosity of 107 times the Sun’s luminosity, how would such a star’s density compare when it is on the main sequence as an O-type star, and when it is a cool supergiant (M-type)? Use values of temperature from Figure 18.14 or Figure 18.15 and the relationship between luminosity, radius, and temperature as given in Exercise 18.47. Figure 18.15 Schematic HR Diagram for Many Stars. Ninety percent of all stars on such a diagram fall along a narrow band called the main sequence. A minority of stars are found in the upper right; they are both cool (and hence red) and bright, and must be giants. Some stars fall in the lower left of the diagram; they are both hot and dim, and must be white dwarfs. Figure 18.14 HR Diagram for a Selected Sample of Stars. In such diagrams, luminosity is plotted along the vertical axis. Along the horizontal axis, we can plot either temperature or spectral type (also sometimes called spectral class). Several of the brightest stars are identified by name. Most stars fall on the main sequence.arrow_forwardWhy is star formation more likely to occur in cold molecular clouds than in regions where the temperature of the interstellar medium is several hundred thousand degrees?arrow_forwardIf the Sun were a member of the cluster NGC 2264, would it be on the main sequence yet? Why or why not?arrow_forward
- Look at the four stages shown in Figure 21.8. In which stage(s) can we see the star in visible light? In infrared radiation? Figure 21.8 Formation of a Star. (a) Dense cores form within a molecular cloud. (b) A protostar with a surrounding disk of material forms at the center of a dense core, accumulating additional material from the molecular cloud through gravitational attraction. (c) A stellar wind breaks out but is confined by the disk to flow out along the two poles of the star. (d) Eventually, this wind sweeps away the cloud material and halts the accumulation of additional material, and a newly formed star, surrounded by a disk, becomes observable. These sketches are not drawn to the same scale. The diameter of a typical envelope that is supplying gas to the newly forming star is about 5000 AU. The typical diameter of the disk is about 100 AU or slightly larger than the diameter of the orbit of Pluto.arrow_forwardWhere in the Galaxy would you expect to find Type II supernovae, which are the explosions of massive stars that go through their lives very quickly? Where would you expect to find Type I supernovae, which involve the explosions of white dwarfs?arrow_forwardIn the text, we said that the five-times ionized oxygen (OVI) seen in hot gas must have been produced by supernova shocks that heated the gas to millions of degrees, and not by starlight, the way H II is produced. Producing OVI by light requires wavelengths shorter than 10.9 nm. The hottest observed stars have surface temperatures of about 50,000 K. Could they produce OVI?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
Stars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning