Concept explainers
(a)
The Schwarzschild radius for a black hole, which has a mass of
(a)
Answer to Problem 39Q
Solution:
The radius is
Explanation of Solution
Given data:
Mass of the black hole is
Formula used:
The expression for the Schwarzschild radius is:
Here,
The conversion formula for km into au is:
The conversion formula from m to km is:
Explanation:
Consider the value of
Recall the expression for Schwarzschild radius.
Substitute
To convert the value of radius from km to au, use the conversion formula.
Conclusion:
Therefore, the Schwarzschild radius of the black hole is
(b)
The angular diameter of a black hole, which is at a distance of
(b)
Answer to Problem 39Q
Solution:
Explanation of Solution
Given data:
The distance between Earth and the center of the galaxy is
Formula used:
The angular diameter can be calculated by the following expression:
Here,
The conversion formula from parsec to au is:
Explanation:
Refer the sub-part (a) for the value of radius of black hole that is
The linear size,
Recall the expression for angular diameter.
Substitute
Conclusion:
The angular diameter is
(c)
The angular diameter of a black hole which is at a distance of
(c)
Answer to Problem 39Q
Solution:
Explanation of Solution
Given data:
The distance between Earth and the center of the galaxy is
Formula used:
The angular diameter can be calculated as,
Here,
Explanation:
Refer the sub-part (a) for the value of radius of black hole that is
The linear size,
Recalling the expression for angular diameter as,
Substitute
Conclusion:
The angular diameter is
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Chapter 22 Solutions
Universe
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- (a) Estimate the height (z) above or below the Galactic plane for the globular cluster M13 (1,b = 59°, 40.9°) and the Orion Nebula (1,b = 209°, -19.4°). M13 and the Orion Nebula are 7 kpc and 450 pc away from Earth respectively. (b) To which components of the Galaxy do these objects probably belong? Explain your answers.arrow_forwardThe best parallaxes obtained with the Hipparcos satellite have an uncertainty such that we believe measurements as low as 0.005 arc-seconds. What is the farthest distance a star can be to have an accurate distance from Hipparcos? 200 Parsecs The disk of our Galaxy is 100,000 light-years in diameter. Using the results from the previous problem, what fraction of the diameter of the Galaxy's disk is the distance for which we can measure accurate parallaxes? 0.0065 The Gaia satellite has greatly improved precision over Hipparcos, measuring parallaxes that are as small as 0.00025 arcseconds. How many times farther away is Gaia be able to measure distances to than Hipparcos?arrow_forwardThe best parallaxes obtained with the Hipparcos satellite have an uncertainty such that we believe measurements as low as 0.005 arc-seconds. What is the farthest distance a star can be to have an accurate distance from Hipparcos?200 parsecs The disk of our Galaxy is 100,000 light-years in diameter. Using the results from the previous problem, what fraction of the diameter of the Galaxy's disk is the distance for which we can measure accurate parallaxes?arrow_forward
- A Type la supernova explodes in a galaxy at a distance of 6.10×107 light-years from Earth. If astronomers detect the light from the supernova today, how many years T have passed since the supernova exploded? T= 2.07 x10 -5 years Given a Hubble constant of 74.3 km/s/Mpc, at what speed v is this galaxy moving away from Earth? v= km/s What is this galaxy's redshift? redshift:arrow_forwarda) Calculate the period of the solar system's orbit around the Milky Way. Assume that we are 8.5 kpc from the galactic center and assume that the mass of the Milky Way interior to our orbit is ~ 10¹¹ solar masses. Alpha Centauri is a multiple star system only 1.34 parsecs away. The apparent magnitudes of the two main stars are: a Cen A: my = +0.01; a Cen B: my = +1.33. b) Calculate the ratio of the flux we receive in the V filter from a Cen A to the flux we receive from a Cen B. c) Calculate the absolute magnitude My of a Cen B.arrow_forward(Astronomy) PSR1913+16 Problem II. Using only the Figure, what are the maximum radial velocities as found from the redshift and blueshift, respectively? Note: redshifts have positive radial velocities values in the figure, whereas blueshifts have negative radial velocity values. (Answer in km/s)arrow_forward