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 10 %. 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 9 × 1011 stars.

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 10 %. 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 9 × 1011 stars.

Foundations of Astronomy (MindTap Course List)

14th Edition

ISBN:9781337399920

Author:Michael A. Seeds, Dana Backman

Publisher:Michael A. Seeds, Dana Backman

Chapter10: The Interstellar Medium

Section: Chapter Questions

Problem 4RQ

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Suppose that stars were born at random times over the last 10e10 years. The rate ofstar formation is simply the number of stars divided by 10e10 years. The fraction ofstars with detected extrasolar planets is at least 9 %. The rate of star formation can bemultiplied by this fraction to find the rate planet formation. How often (in years) doesa planetary system form in our galaxy? Assume the Milky Way contains 7 × 10e11 stars. I've done this problem 3 different times from scratch and looked at similar problems here. Each time my answer is 1.587 (1.59 rounded to 2 significant figures), but when I submit, it says the answer is wrong. What do you think?
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Consider the Milky Way disk, which has a 50 kpc diameter and a total height of 600 pc. Suppose that the Sun orbits precisely at the mid-plane of the disk in a circular orbit. Supernovae explosions happen randomly throughout the disk at a rate of about 2 per 100 years. Consider a spherical region around the Sun with a radius of 300 pc. Ignore the Milky Way bulge and halo in this problem; assume the Milky Way disk is perfectly uniform and extends all the way through the region of the bulge. (I.e., the Milky Way is modeled *only* as a cylindrical disk--like a hockey puck-- with constant density throughout.) If a particular supernova goes off at a random location within the disk, what is the probability that it went off in the 300 pc radius spherical region near the Sun? Express your probability as a percentage (but without writing the percent sign). [Hint: there is a 100% probability that the supernova went off somewhere in the volume of the Milky Way disk; there is a 50% probability that…
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A star is formed when the gravitational attraction overcomes the pressure due to the gases inside.Thus we can write(in-picture) .... Assuming the ideal gas equation, we can write P = nkT, where n is the number of atoms/volume. Let M and m denote the total mass and the mass of each gas atom. Using the above equation, show that the condition for star formation is that the mass of the star obeys M > MJ, where : (in-picture)
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