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According to a model described in the text, a neutron star has a radius of about 10 km. Assume that the pulses occur once per rotation. According to
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- The star HD 69830's mass is 1.7 ✕ 1030 kg, its radius is 6.3 ✕ 105 km, and it has a rotational period of approximately 35 days. If HD 69830 should collapse into a white dwarf of radius 7.8 ✕ 103 km, what would its period (in s) be if no mass were ejected and a sphere of uniform density can model HD 69830 both before and after?arrow_forwardAs a person approaches the Schwarzschild radius of a black hole, outside observers see all the processes of that person (their clocks, their heart rate, etc.) slowing down, and coming to a halt as they reach the Schwarzschild radius. (The person falling into the black hole sees their own processes unaffected.) But the speed of light is the same everywhere for all observers. What does this say about space as you approach the black hole?arrow_forwardwhat is the mass of the black hole ? give your answer as a multiple of Ms where Ms is the solar mass, Ms = 2.0 * 10^(30) express your answer as a multiple of the solar mass mass Ms.arrow_forward
- A cepheid star is located at a distance of 18.7kpc from the Earth and has an apparent visual magnitude of 13.1. Determine its pulsation period in days. Consider the following expression of the Leavitt relation MV=−2.78logPdays−1.35��=−2.78log�days−1.35, where MV�� is the absolute visual magnitude and Pdays�days the pulsation period in days to 2 decimal places.arrow_forward(Astronomy) PSR1913+16 Problem III. As the shape of the graph shown is not skewed, the orbit can be assumed circular. Also assume the system is viewed edge-on (that is, the orbital system is not inclined to the observer). Using these assumptions, the maximum radial velocities, and the orbital period T = 7.75 hours, find the orbital radii of the stars from the center of mass. (Hints: The figures below may be helpful. Use v = 2πr/P, where v is velocity, P is period, and r is radius. Note: redshifts have positive radial velocities values in the upper figure, whereas blueshifts have negative radial velocity values.)arrow_forwardA spinning neutron star of mass M=1.4 solar masses, constant density, and radius R=10 km has a period P=1s. The neutron star is accepting mass from a binary companion through an accretion disk, at a rate of dM/dt=10^-9 solar masses per year. Assume the accreted matter is in a circular Keplerian orbit around the neutron star until just before it hits the surface, and once it does then all of the matter's angular momentum is transferred onto the neutron star. Derive a differential equation for dP/dt, the rate at which the neutron-star period decreases. *I know the formula for the inertial of a uniform-density sphere is equal to .4MR^2, the relationship between the period and angular velocity is (omega)=2pi/(P), and the rotational kinetic energy is .5I(omega)^2 (don't know if this one is important for the problem but here it is anyways)*arrow_forward
- The Millennium Falcon is approximately 35.8 m long. There are conflicting reports, but the Falcon made the Kessel Run in approximately 12.86 parsecs. This is an odd unit to measure speed with as a parsec is a unit of length equal to 3.26 light-year. The science FICTION comes in when you consider that ships in Star Wars use hyperdrive to travel faster than the speed of light, so they are able to make jumps through space. Han Solo picked difficult or dangerous points to jump between to make the trip so short. Let's imagine that the Millennium Falcon travels at 0.97c during the 12.86 parsec Kessel Run. What distance, in light-year, does an observer at the finish line measure for the trip? Don't forget to convert parsec to light-year. light-year What distance, in light-year, does Han Solo measure for the trip as he pilots the ship? light-year Which person measures the proper distance of the trip? Which person would measure the proper length of the Millennium Falcon? ✪arrow_forwardHow close, r, to the center of a neutron star would a manned satellite be orbiting if it were at the location where the gravitational force from the star equaled the gravitational force of the Earth's surface? RN = neutron star radius = 1 × 104 kmM N = neutron star mass = 3 × 1030 kgG = universal gravitational constant = 6.67 × 10-11 N m2 / kg2g⊕ = Earth gravitational acceleration = 9.807 m/s²arrow_forwardDouble stars are stars which are close enough and move slowly enough that they orbit each other. Each star is located at the focus of the ellipse of its orbit around the other star. Consider a binary star system which has an average angular separation of 6.1" arc and a period of 87.3 years. The annual parallax of the stars, p, is 0.192"arc. We call the measure of the angular separation of the two stars, . [remember that 1 degree is divided into 60 'arc (read this as 60 minutes of arc) and each 1'arc is subdivided into 60"arc (read this as 60 seconds of arc)]. The distance to the binarystar system is calculated from its parallax , p, of 0.192"arc, which has been measured carefully over a period of the last 92 years. First we must calculate the distance to the binary system: D = 1/p where p is the parallax in seconds of arc giving D in parsecs. The distance, D = 1/p = ________ pc How many light years does this correspond to? (remember that 1 pc = 3.26 lt yr) D (in light…arrow_forward
- Many galaxies appear to have supermassive black holes in their centers powering active galactic nuclei (also called AGN). The Schwarzschild radius of these supermassive black holes can be estimated in part by watching for changes in the brightness of the surrounding AGN and measuring the timescale of those changes. Assume we observe an AGN and determine it varies with a timescale of 9.85 minutes, which implies a Schwarzschild radius on the order of 1.77x1011 meters. Estimate the mass of this supermassive black hole. kgarrow_forwardThe Millennium Falcon is approximately 35.2 m long. There are conflicting reports, but the Fàlcon made the Kessel Run in approximately 12.95 parsecs. This is an odd unit to measure speed with as a parsec is a unit of length equal to 3.26 light-year. The science FICTION comes in when you consider that ships in Star Wars use hyperdrive to travel faster than the speed of light, so they are able to make jumps through space. Han Solo picked difficult or dangerous points to jump between to make the trip so short.tet's imagine that the Millennium Falcon travels at 0.95c during the 12.95 parsec Kessel Run. What distance, in light-year, does an observer at the finish line measure for the trip? Don't forget to convert parsec to light-year. light-year What distance, in light-year, does Han Solo measure for the trip as he pilots the ship? | light-yeararrow_forwardIf the radius of the Sun is 7 x 108 m, how does the black hole’s radius compare? (Divide the radius of the Sun by the Schwarzschild radius). Your answer should be in the form of “The Sun is _____ times smaller/bigger than the black hole.” Rsun=7x108 m Rs=29.64kmarrow_forward
- Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning