Astronomical observations of our milky way galaxy indicate that it has a mass of about 8x1011 solar masses. A star orbiting near the galaxy's periphery is 5.6x104 light years from its center. a.) What should be the orbital period (in years) of that star be? b.) If its period is 6.4x107 years instead, what is the mass (in solar masses) of the galaxy? Such calculations are used to imply the existence of "dark matter" in the universe and have indicated, for example, the existence of very massive black holes at the center of some galaxies.

Astronomical observations of our milky way galaxy indicate that it has a mass of about 8x1011 solar masses. A star orbiting near the galaxy's periphery is 5.6x104 light years from its center. a.) What should be the orbital period (in years) of that star be? b.) If its period is 6.4x107 years instead, what is the mass (in solar masses) of the galaxy? Such calculations are used to imply the existence of "dark matter" in the universe and have indicated, for example, the existence of very massive black holes at the center of some galaxies.

Similar questions

The supermassive black hole at the center of a galaxy has a mass of 6.5 billion solar masses. If we assume that it is a Schwarzschild black hole, what is the radius of this black hole? A. 18 light hours B. 20 light hours C. 16 light hours D. 14 light hours Is the answer A? S. radius = 3 x 6.5 x 109 x 9.26567-10 = 18.1 light hours Thanks!
The solar system has a planet with an orbital period T1b=1.51d and an orbital radius of R1b=1.6456x10^6km. Another planet in the system has an orbital radius of R1f=5.5352x10^6 km. Calculate its orbital period in days.
help asap
Use Kepler’s 3rd Law to calculate the mass of a star which has a planet orbiting at 2.35 A.U. and takes 4.56 Earth years to complete one full orbit.
Problem 6. (Palen, et. al., 2nd ed., Problem 49) Sirius and its companion orbit around a common center of mass with a period of 50 years. The mass of Sirius is 2.02 times the mass of the Sun. a) If the orbital velocity of the companion is 2.07 times greater than that of Sirius, what is the mass of the companion? b) What is the semimajor axis of the orbit?
I need help with this hw problem.
According to Lunar Laser Ranging experiment the average distance LM from the Earth to the Moon is approximately 3.92 x 105 km. The Moon orbits the Earth and completes one revolution relative to the stars in approximately 27.5 days (a sidereal month). Calculate the orbital velocity of the Moon in m/s. Answer: Choose...
4. A binary system is composed of two identical stars orbiting each other with some period To. a) Now imagine scaling all lengths (separation between the stars and the radius of the stars) by a factor k, but keeping the density of the stars the same. By what factor does the period change? b) Now instead of scaling the lengths, scale the density by k (i.e. p → kx p). By what factor does the period change?
Supermassive black holes are thought to exist at the center of many galaxies. What is the radius of such an object if it has a mass of 109 Suns?
Recently, astronomers have observed stars and other objects that orbit the center of the Milky Way Galaxy farther out than our Sun, but move around faster than we do. How do astronomers think such an observation can be explained? A, all these faster-moving objects must be escaping from the gravity of the Milky Way and will soon be lost to our Galaxy B. each of the faster-moving outer objects must be the result of a supernova explosion (giving them extra speed) C, it is the Sun that is moving too slowly because of a collision billions of years ago; the outer objects are really moving at the appropriate speed for their distance from the center D there must be a great deal of invisible dark matter outside the orbit of the Sun whose gravitational pull explains the faster motions we see out there E. no one can come up with any explanation for this puzzling observation
In a spiral galaxy, the orbital speeds of stars far from the galaxy's center distance from the center increases. as the A. increase B. decrease C. are approximately the same D. The answer changes depending on the galaxy.
Astronomers have observed an otherwise normal star, called S2, closely orbiting an extremely massive but small object at the center of the Milky Way Galaxy called SgrA. S2 moves in an elliptical orbit around SgrA with a period of 15.2 yr and an eccentricity ee = 0.87. In 2002, S2 reached its closest approach to SgrA, a distance of only 123 AU (1AUAU = 1.50×1011m1.50×1011m is the mean Earth - Sun distance). Determine the mass MM of SgrA, the massive compact object (believed to be a supermassive black hole) at the center of our Galaxy. State MM in kgkg and in terms of the mass of our Sun. Express your answer using two significant figures.