Universe: Stars And Galaxies
6th Edition
ISBN: 9781319115098
Author: Roger Freedman, Robert Geller, William J. Kaufmann
Publisher: W. H. Freeman
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Chapter 23, Problem 15Q
To determine
Whether or not, it would be likely to find planets, composed of heavy elements, in the disk of spiral galaxy, in the nucleus of a spiral or in elliptical or irregular galaxies.
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A star with mass 1.05 M has a luminosity of 4.49 × 1026 W and effective temperature of 5700 K. It dims to 4.42 × 1026 W every 1.39 Earth days due to a transiting exoplanet. The duration of the transit reveals that the exoplanet orbits at a distance of 0.0617 AU. Based on this information, calculate the radius of the planet (expressed in Jupiter radii) and the minimum inclination of its orbit to our line of sight.
Follow up observations of the star in part reveal that a spectral feature with a rest wavelength of 656 nm is redshifted by 1.41×10−3 nm with the same period as the observed transit. Assuming a circular orbit what can be inferred about the planet’s mass (expressed in Jupiter masses)?
Suppose that stars were born at random times over the last 1010 years. The rate of star formation is simply the number of stars divided by 1010 years. The fraction of stars with detected extrasolar planets is at least 18%. The rate of star formation can be multiplied by this fraction to find the rate planet formation. How often (in years) does a planetary system form in our galaxy? Assume the Milky Way contains 8 × 1011 stars.
Some interstellar Properties.
Use excel calculator to fill in the missing figures.
1 ly = 365 × 24 × 60 × 60 × 300, 000km/s = 9.46 × 10^12 km
Chapter 23 Solutions
Universe: Stars And Galaxies
Ch. 23 - Prob. 1QCh. 23 - Prob. 2QCh. 23 - Prob. 3QCh. 23 - Prob. 4QCh. 23 - Prob. 5QCh. 23 - Prob. 6QCh. 23 - Prob. 7QCh. 23 - Prob. 8QCh. 23 - Prob. 9QCh. 23 - Prob. 10Q
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