DP Physics Questionbank

Description

Nature of science:

Evidence: The simple light spectra of a gas on Earth can be compared to the light spectra of distant stars. This has allowed us to determine the velocity, composition and structure of stars and confirmed hypotheses about the expansion of the universe. (1.11)

Understandings:

• Stellar spectra
• Hertzsprung–Russell (HR) diagram
• Mass–luminosity relation for main sequence stars
• Cepheid variables
• Stellar evolution on HR diagrams
• Red giants, white dwarfs, neutron stars and black holes
• Chandrasekhar and Oppenheimer–Volkoff limits

Applications and skills:

• Explaining how surface temperature may be obtained from a star’s spectrum
• Explaining how the chemical composition of a star may be determined from the star’s spectrum
• Sketching and interpreting HR diagrams
• Identifying the main regions of the HR diagram and describing the main properties of stars in these regions
• Applying the mass–luminosity relation
• Describing the reason for the variation of Cepheid variables
• Determining distance using data on Cepheid variables
• Sketching and interpreting evolutionary paths of stars on an HR diagram
• Describing the evolution of stars off the main sequence
• Describing the role of mass in stellar evolution

Guidance:

• Regions of the HR diagram are restricted to the main sequence, white dwarfs, red giants, super giants and the instability strip (variable stars), as well as lines of constant radius
• HR diagrams will be labelled with luminosity on the vertical axis and temperature on the horizontal axis
• Only one specific exponent (3.5) will be used in the mass–luminosity relation
• References to electron and neutron degeneracy pressures need to be made

Data booklet reference:

Theory of knowledge:

• The information revealed through spectra needs a trained mind to be interpreted. What is the role of interpretation in gaining knowledge in the natural sciences? How does this differ from the role of interpretation in other areas of knowledge?

Utilization:

• An understanding of how similar stars to our Sun have aged and evolved assists in our predictions of our fate on Earth

Aims:

• Aim 4: analysis of star spectra provides many opportunities for evaluation and synthesis
• Aim 6: software-based analysis is available for students to participate in astrophysics research

Directly related questions

• 18M.3.SL.TZ1.11c: Star X is likely to evolve into a stable white dwarf star. Outline why the radius of a white...
• 18M.3.SL.TZ1.11b.iii: Estimate the mass of star X (MX) in terms of the mass of the Sun (Ms).
• 18M.3.SL.TZ1.11b.ii: Determine the radius of star X (RX) in terms of the radius of the Sun (Rs).
• 18M.3.SL.TZ1.11b.i: Write down the luminosity of star X (LX) in terms of the luminosity of the Sun (Ls).
• 18M.3.SL.TZ1.11a.ii: Show that the temperature of star X is approximately 10 000 K.
• 18M.3.SL.TZ1.11a.i: Suggest, using the graphs, why star X is most likely to be a main sequence star.
• 18M.3.SL.TZ2.11e: Discuss, with reference to its change in mass, the evolution of star P from the main sequence...
• 18M.3.SL.TZ2.11d.iii: plot the position, using the letter G, of Gacrux.
• 18M.3.SL.TZ2.11d.ii: plot the position, using the letter P, of the main sequence star P you calculated in (b).
• 18M.3.SL.TZ2.11d.i: draw the main sequence.
• 17N.3.SL.TZ0.12e.ii: sketch the expected evolutionary path for Sirius A.
• 17N.3.SL.TZ0.12e.i: draw the approximate positions of Sirius A, labelled A and Sirius B, labelled B.
• 17N.3.SL.TZ0.12d.ii: Identify the star type of Sirius B.
• 17N.3.SL.TZ0.12d.i: Determine the radius of Sirius B in terms of the radius of the Sun.
• 17M.3.SL.TZ2.12c.ii: Describe how type Ia supernovae could be used to measure the distance to this galaxy.
• 17M.3.SL.TZ2.11c.iv: Determine the region of the electromagnetic spectrum in which the neutron star in (c)(iii) emits...
• 17M.3.SL.TZ2.11c.ii: Outline why the neutron star that is left after the supernova stage does not collapse under the...
• 17M.3.SL.TZ2.11c.i: On the HR diagram in (b), draw a line to indicate the evolutionary path of star X.
• 17M.3.SL.TZ2.11b: The Hertzsprung–Russell (HR) diagram shows two main sequence stars X and Y and includes lines of...
• 17M.3.SL.TZ1.9c: The Sun and Theta 1 Orionis will eventually leave the main sequence. Compare and contrast the...
• 17M.3.SL.TZ1.9a.ii: Show that the mass of Theta 1 Orionis is about 40 solar masses.
• 17M.3.SL.TZ1.10a.ii: The present temperature of the CMB is 2.8 K. Calculate the peak wavelength of the CMB.
• 16N.3.SL.TZ0.16b: Explain why Cephids are used as standard candles.
• 16N.3.SL.TZ0.16a: Determine the distance from Earth to the Cepheid star in parsecs. The luminosity of the Sun is...
• 16N.3.SL.TZ0.15e: A standard Hertzsprung–Russell (HR) diagram is shown. Using the HR diagram, draw the present...
• 16N.3.SL.TZ0.15d: Alpha Centauri A is in equilibrium at constant radius. Explain how this equilibrium is maintained.
• 16N.3.SL.TZ0.15c: Show, without calculation, that the radius of Alpha Centauri B is smaller than the radius of...
• 16M.3.SL.TZ0.13e: Predict the likely future evolution of Aldebaran.
• 16M.3.SL.TZ0.13d: Identify the element that is fusing in Aldebaran’s core at this stage in its evolution.
• 16M.3.SL.TZ0.13c: Outline how the light from Aldebaran gives evidence of its composition.
• 16M.3.SL.TZ0.13b: The radius of Aldebaran is 3.1×1010 m. Determine the luminosity of Aldebaran.
• 16M.3.SL.TZ0.13a: Show that the surface temperature of Aldebaran is about 4000 K.
• 15M.3.HL.TZ1.4a: Identify whether star X is on the main sequence. Assume that n = 3.5 in the mass–luminosity...
• 15M.3.HL.TZ1.4b: (i) State the evolution of star X. (ii) Explain the eventual fate of star X.
• 15M.3.SL.TZ1.15a: (i) Show that the surface temperature of Barnard’s star is about 3000 K. (ii) Suggest why...
• 15M.3.SL.TZ2.13a: State the star type for A, B and C.
• 15M.3.SL.TZ2.13d: The graph shows the variation with wavelength λ of the intensity I of the radiation emitted by...
• 15M.3.HL.TZ2.4a: The mass of a main sequence star is two solar masses. Estimate, in terms of the solar luminosity,...
• 15M.3.HL.TZ2.4b: The star in (a) will eventually leave the main sequence. State (i) the condition that must be...
• 15M.3.HL.TZ2.4c: Explain why a white dwarf maintains a constant radius.
• 14M.3.SL.TZ1.12: This question is about the life history of stars. Outline, with reference to pressure, how a...
• 14M.3.HL.TZ1.2a: Outline, with reference to pressure, how a star on the main sequence maintains its stability.
• 14M.3.HL.TZ1.2b: A star with a mass equal to that of the Sun moves off the main sequence. Outline the main...
• 14M.3.HL.TZ1.2c: Compare the fate of the star in (b) with that of a star of much greater mass.
• 15N.3.SL.TZ0.15d: Outline how observers on Earth can determine experimentally the temperature of a distant star.
• 14N.3.HL.TZ0.4c.i: Using the HR diagram on page 6, draw the evolutionary path of Phi-1 Orionis as it leaves the main...
• 14N.3.HL.TZ0.4a: Calculate the luminosity of Phi-1 Orionis in terms of the luminosity of the Sun. Assume that...
• 14N.3.HL.TZ0.4b: The Sun is expected to have a lifespan of around \({\text{1}}{{\text{0}}^{{\text{10}}}}\) years....
• 14N.3.HL.TZ0.4c.ii: Outline, with reference to the Oppenheimer–Volkoff limit, the fate of Phi-1 Orionis.
• 14M.3.HL.TZ2.4b: Outline why Achernar will spend less time on the main sequence than the Sun.
• 14M.3.HL.TZ2.4a: Achernar is a main sequence star with a mass that is eight times the mass of the Sun. Deduce that...
• 14M.3.HL.TZ2.4c: (i)     State the condition relating to mass that must be satisfied for Achernar to become a...
• 14M.3.SL.TZ2.12b: State how (i)     it is known that main sequence stars are made predominantly of...
• 14M.3.SL.TZ2.12c: The graph shows the variation with wavelength of the intensity of a main sequence...
• 13M.3.SL.TZ1.14a: The peak in the radiation spectrum of a star X is at a wavelength of 300 nm. Show that the...
• 13M.3.SL.TZ1.14c: On the Hertzsprung–Russell diagram, label the position of star X with the letter X.  
• 13M.3.HL.TZ1.2c: On the Hertzsprung–Russell diagram, label (i) the position of star X with the letter X.(ii) the...
• 13M.3.HL.TZ1.2d: Explain, with reference to the Chandrasekhar limit, whether or not star X will become a white dwarf.
• 13M.3.HL.TZ2.3a: The Hertzsprung–Russell (HR) diagram shows the Sun, a star A and the main sequence. Using the...
• 13M.3.HL.TZ2.3b: Star A will leave the main sequence and will evolve to become a neutron star. State the (i)...
• 12M.3.HL.TZ1.3a: (i) On the diagram above, draw a line to show the evolutionary path of the Sun from its present...
• 12M.3.HL.TZ1.3b: (i) Show that the mass of star X is approximately 14 solar masses. (Assume that n=3.5 in the...
• 11M.3.SL.TZ2.14c: On the Hertzsprung–Russell diagram above, (i) label the position of Betelgeuse with the letter...
• 11M.3.HL.TZ2.3a: State what is meant by the (i) Chandrasekhar limit. (ii) Oppenheimer–Volkoff limit.
• 11M.3.HL.TZ2.3b: Suggest how your answers in (a) can be used to predict the fate of a main sequence star.
• 11N.3.SL.TZ0.11a: On the grid of the Hertzsprung–Russell (HR) diagram shown, draw a line to represent the...
• 12N.3.HL.TZ0.4a: A main sequence star has a mass of 2.2\({M_ \odot }\) where \({M_ \odot }\)=  1 solar mass. The...
• 12N.3.HL.TZ0.4b: The star in (a) will evolve to become a white dwarf. The diagram represents the stages in the...
• 11N.3.HL.TZ0.1e: On the HR diagram on page 2, draw the evolutionary path of Barnard’s star after it leaves the...
• 12M.3.HL.TZ2.1c: Betelgeuse in the constellation of Orion is a red supergiant star. (i) Compare the fate of...
• 12M.3.SL.TZ2.13c: Distances to galaxies may be determined by using Cepheid variable stars. By considering the...
• 12N.3.SL.TZ0.15b: A Cepheid star and non-Cepheid star both belong to the same distant galaxy. Explain, stating the...
• 12M.3.HL.TZ2.1d: Distances to galaxies may be determined by using Cepheid variable stars. By considering the...
• 13N.3.HL.TZ0.1f: On the HR diagram above, sketch the likely evolutionary path of Luyten’s star.
• 13N.3.SL.TZ0.11e: Gomeisa, Luyten’s star and the Sun are main sequence stars. On the grid of the...
• 11M.3.SL.TZ1.14a: (i) Draw a circle around the stars that are red giants. Label this circle R. (ii) Draw a circle...
• 11M.3.SL.TZ1.14b: Explain, without doing any calculation, how astronomers can deduce that star B has a larger...
• 11M.3.HL.TZ1.4a: Assuming that the exponent n in the mass–luminosity relation is 3.5, show that the mass of Khad...
• 11M.3.HL.TZ1.4b: Outline the likely evolution of the star Khad after it leaves the main sequence.
• 10N.3.HL.TZ0.E1i: The luminosity of the main sequence star Regulus is \(150{\text{ }}{L_{\text{S}}}\). Assuming...
• 10N.3.HL.TZ0.E1j: (i)     other possible outcome of the final stage of the evolution of Betelgeuse. (ii)    ...