Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 21, Problem 11Q
To determine
The year in which the Earth observers would have seen the supernova explosion that formed the Crab Nebula.
To determine
(b)
Whether or not, answer of part (a) agrees with the known year of supernova, 1054 C.E. Reason for discrepancies (if any).
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
International Astronomical Union reported on 24 Feb 1987:
An object was discovered on Feb. 24.37 UT (position R.A. = 5h35m.8, Decl. = -69
18'), obtained m = 4.8 on Feb. 24.454 UT. This object proved to be the most famous
supernova (SN) in the 20th Century and the brightest visible from Earth since 1604.
It is classified as a SN of the type Il in the Large Magellanic Cloud (SN1987A). Its
brightness peaked in May 1987, with an apparent magnitude of m = 2.8.
a) Find the absolute magnitude M of the SN1987A at maximum. Distance of the
LMC is 51,400 pc.
b) The progenitor (before SN explosion) star was a blue supergiant of the
apparent magnitude m = 12.8. How much brighter (in terms of flux density)
this SN was at maximum compared to the progenitor star. Find the ratio FSN /
Ebefore
Consider the image above of the Cassiopeia A (Cas A) supernova remnant. The supernova explosion that caused this remnant was observed on earth about 300 years ago. It is about 3000 pc away. Since that time, the shockwave from the supernova has expanded to form the roughly spherical cloud pictured above. From the center point to the edge of the cloud is about 3 pc. Compute the angular diameter of the Cas A supernova remnant as viewed from Earth. Express your answer in arcminutes.
An astronomical image shows two objects that have the same apparent magnitude, i.e., the same brightness. However, spectroscopic follow up observations indicate that while one is a star that is within our galaxy, at a distance dgal away, and has the same luminosity as the Sun, the other is a quasar and has 100x the luminosity of the entire Milky Way galaxy. What is the distance to the quasar? (You may assume, for this rough calculation, that the Milky Way has 1011 stars and that they all have the luminosity as the Sun.) Give your response in Mpc. Value: dgal = 49 pc
Chapter 21 Solutions
Universe: Stars And Galaxies
Ch. 21 - Prob. 1QCh. 21 - Prob. 2QCh. 21 - Prob. 3QCh. 21 - Prob. 4QCh. 21 - Prob. 5QCh. 21 - Prob. 6QCh. 21 - Prob. 7QCh. 21 - Prob. 8QCh. 21 - Prob. 9QCh. 21 - Prob. 10Q
Ch. 21 - Prob. 11QCh. 21 - Prob. 12QCh. 21 - Prob. 13QCh. 21 - Prob. 14QCh. 21 - Prob. 15QCh. 21 - Prob. 16QCh. 21 - Prob. 17QCh. 21 - Prob. 18QCh. 21 - Prob. 19QCh. 21 - Prob. 20QCh. 21 - Prob. 21QCh. 21 - Prob. 22QCh. 21 - Prob. 23QCh. 21 - Prob. 24QCh. 21 - Prob. 25QCh. 21 - Prob. 26QCh. 21 - Prob. 27QCh. 21 - Prob. 28QCh. 21 - Prob. 29QCh. 21 - Prob. 30QCh. 21 - Prob. 31QCh. 21 - Prob. 32QCh. 21 - Prob. 33QCh. 21 - Prob. 34QCh. 21 - Prob. 35QCh. 21 - Prob. 36QCh. 21 - Prob. 37QCh. 21 - Prob. 38QCh. 21 - Prob. 39QCh. 21 - Prob. 40QCh. 21 - Prob. 41QCh. 21 - Prob. 42QCh. 21 - Prob. 43QCh. 21 - Prob. 44QCh. 21 - Prob. 45QCh. 21 - Prob. 46QCh. 21 - Prob. 47QCh. 21 - Prob. 48QCh. 21 - Prob. 49QCh. 21 - Prob. 50QCh. 21 - Prob. 51QCh. 21 - Prob. 52QCh. 21 - Prob. 53QCh. 21 - Prob. 54QCh. 21 - Prob. 55QCh. 21 - Prob. 56QCh. 21 - Prob. 57QCh. 21 - Prob. 58QCh. 21 - Prob. 59QCh. 21 - Prob. 60QCh. 21 - Prob. 61QCh. 21 - Prob. 62QCh. 21 - Prob. 63QCh. 21 - Prob. 64QCh. 21 - Prob. 65QCh. 21 - Prob. 66QCh. 21 - Prob. 67QCh. 21 - Prob. 68QCh. 21 - Prob. 69QCh. 21 - Prob. 70QCh. 21 - Prob. 71QCh. 21 - Prob. 72QCh. 21 - Prob. 73QCh. 21 - Prob. 74QCh. 21 - Prob. 75Q
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
- An object was discovered on Feb. 24.37 UT (position R.A. = 5h35m.8, Decl. = -69 18'), obtained m = 4.8 on Feb. 24.454 UT. This object proved to be the most famous supernova (SN) in the 20th Century and the brightest visible from Earth since 1604. It is classified as a SN of the type Il in the Large Magellanic Cloud (SN1987A). Its brightness peaked in May 1987, with an apparent magnitude of m = 2.8. a) Find the absolute magnitude M of the SN1987A at maximum. Distance of the LMC is 51,400 pc. b) The progenitor (before SN explosion) star was a blue supergiant of the apparent magnitude m = 12.8. How much brighter (in terms of flux density) this SN was at maximum compared to the progenitor star. Find the ratio FSN/ Ebetorearrow_forwardLet us imagine that the spectrum of a star is collected and we find the absorption line of Hydrogen-Alpha (the deepest absorption line of hydrogen in the visible part of the electromagnetic spectrum) to be observed at 656.5 nm instead of 656.3 nm as measured in a lab here on Earth. What is the velocity of this star in m/s? (Hint: speed of light is 3*10^8 m/s; leave the units off of your answer)arrow_forwardLet us imagine that the spectrum of a star is collected and we find the absorption line of Hydrogen-Alpha (the deepest absorption line of hydrogen in the visible part of the electromagnetic spectrum) to be observed at 656.5 nm instead of 656.3 nm as measured in a lab here on Earth. What is the velocity of this star in m/s? (Hint: speed of light is 3*10^8 m/s; leave the units off of your answer) Question 4 of 7 A Moving to another question will save this response. 1 6:59 & backsarrow_forward
- The difference in absolute magnitude between two objects is related to their fluxes by the flux-magnitude relation: FA / FB = 2.51(MB - MA) A distant galaxy contains a supernova with an absolute magnitude of -19. If this supernova were placed next to our Sun (M = +4.8) and you observed both of them from the same distance, how much more flux would the supernova emit than the Sun? Fsupernova / FSun = ?arrow_forwardTime left 1:45:56 A star has initially a radius of 680000000 m and a period of rotation about its axis of 33 days. Eventually it changes into a neutron star with a radius of only 45000 m and a period of 0.3 s. Assuming that the mass has not changed, find Assume a star has the shape of a sphere. (Suggestion: do it with formula first, then put the numbers in) [Recommended time : 5-8 minutes] (a) the ratio of initial to final angular momentum (Li/Lf) Oa. 2.17E+15 Ob. 24 Oc. 0.0416 Od. 4.61E-16 (b) the ratio of initial to final kinetic energy Oa. 4.85E-23 Ob. 396000 Oc. 2.53E-6 Od. 2.06E+22arrow_forwardI attempted to answer this question and I'm not sure what I am doing wrong. My formula says A.S. = 206265 (separation/distance from observer) I know to convert to the same units, so I ended up with 80 Million Km being 8 x 10 ^ -6 LY Could you please explain each step especially for the part that I got wrong for both A and B?arrow_forward
- Recall that Hubble’s Law is given by V=HR; this means that H has units of inverse seconds (1/sec). A convenient laboratory set of units is to give H in km per sec per megaparsec. A parsec is 3.26 light years and the speed of light is 3 X 105 km/sec. Use 3.156 X 107 sec/yr. The first data off the then new Hubble Space telescope suggested a value of H equal to 108 km per sec per megaparsec. What is H in inverse seconds? Hint divide by the number of km in a megaparsec.arrow_forward= 2000 K and a radius of R, A young recently formed planet has a surface temperature T Jupiter radii (where Jupiter's radius is 7 x 107 m). Calculate the luminosity of the planet and 2 determine the ratio of the planet's luminosity to that of the Sun.arrow_forwardA main sequence star of mass 25 M⊙has a luminosity of approximately 80,000 L⊙. a. At what rate DOES MASS VANISH as H is fused to He in the star’s core? Note: When we say “mass vanish '' what we really mean is “gets converted into energy and leaves the star as light”. Note: approximate answer: 3.55 E14 kg/s b. At what rate is H converted into He? To do this you need to take into account that for every kg of hydrogen burned, only 0.7% gets converted into energy while the rest turns into helium. Approximate answer = 5E16 kg/s c. Assuming that only the 10% of the star’s mass in the central regions will get hot enough for fusion, calculate the main sequence lifetime of the star. Put your answer in years, and compare it to the lifetime of the Sun. It should be much, much shorter. Approximate answer: 30 million years.arrow_forward
- The difference in absolute magnitude between two objects at the same distance is related to their fluxes by the flux-magnitude relation. FA FB = 2.51(MB − MA) A distant galaxy contains a type I classical Cepheid whose period results in an absolute magnitude estimate of −6.3. If this star were placed next to our Sun (M = +4.8) and you observed them both from the same distance, how much more flux would the Cepheid emit than the Sun? FCepheid FSun = If a galaxy contains a supernova that at its brightest has an apparent magnitude of +11, how far away is the galaxy? Assume that the absolute magnitude of the supernova is −18. Hint: Use the magnitude-distance formula: d = 10(mV − MV + 5)/5 . The hydrogen Balmer line H? has a wavelength of 486.1 nm. It is shifted to 559.7 nm in a quasar's spectrum. What is the redshift of this quasar? (Hint: What is Δ??)arrow_forwardWhat is the right ascension in hours, minutes, and seconds of a star at RA 239.768°?arrow_forwardCalculate by how many times Betelgeuse is brighter than the Sun, if its parallax is 0.006 arcsec, and its apparent magnitude is m = +.5. Can you first use the parallax to calculate the distance and then use the magnitude-distance formula to find the absolute magnitude of Betelgeuse and finally, compare it to the absolute magnitude of the Sun which is -26,74 because other experts used other methods and the answer was not correct.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
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