The Sun's mass is 2.0x1030 kg, its radius is 7.0x105 km, and it has a rotational period of approximately 28 days. If the Sun should collapse into a white dwarf of radius 3.7x103 km, what would its period be if no mass were ejected and a sphere of uniform density can model the Sun both before and after?

The mass-luminosity relation describes the mathematical relationship between luminosity and mass for main sequence stars.  It describes how a star with a mass of 4 M⊙ would have a luminosity of ______ L⊙. If a star has a radius 1/2 that of the Sun and a temperature 4 that of the Sun, how many times higher is the star's luminosity than that of the Sun? (If it is smaller by a factor of 8, you would write 0.125 because 1/8=0.125) If a star has a radius 2 times larger than the Sun's and a luminosity 1/4th that of the Sun, how many times higher is the star's temperature than that of the Sun? (If it is smaller by a factor of 8, you would write 0.125 because 1/8=0.125) If a star has a surface temperature 2 times lower than the Sun's and a luminosity the same as the Sun, how many times larger is the star than the Sun? (If it is smaller by a factor of 8, you would write 0.125 because 1/8=0.125)

What is the size of a typical white dwarf? Group of answer choices   1.0 solar radii   0.5 solar radii   0.1 solar radii (roughly the size of Jupiter)   0.01 solar radii (roughly the size of Earth)   5 solar radii

The Sun has a radius of 6.955×105 km and a mass of 1.989×1030  kg. What is the density of the Sun? Answer: ____ kg/m3 How does this compare to the density of Earth (5500 kg/m3)? Answer: ____ times the density of Earth

QUESTION 16 Use the figure shown below to complete the following statement: A low-mass protostar (0.5 to 8M the mass compared to our sun) remains roughly constant in decreases in until it makes a turn towards the main sequence, as it follows its evolutionary track. Protostars of different masses follow diferent paths on their way to the main sequence. 107 Luminosity (L) 10 105 10 107 10² 101 1 10-1 10-2 10-3 Spectral type 0.01 R 0.001 Re 60 M MAIN SEQUENCE 40,000 30,000 20 Mau 10 Mgun 5 Mun 0.1 Run Ren radius; temperature luminosity; radius 3 Min. 05 BO temperature; luminosity Oluminosity: temperature radius: luminosity 1 M 10,000 6000 Surlace temperature (K) 1,000 Rs 2 M STAR L 0.8 M B5 AO FOGO КБ МБ -10 +10 3000 Absolute visual magnitude and

Match the spectral type and luminosity class to theletters shown on the Hertzsprung-Russell diagram 1) A WD (White Dwarf)2) G V (Main Sequence) 3) M V (Main Sequence)4) M I (Supergiant)5) G III (Giant)

The flux received at the Earth from Supernova 1885 was 3.0182 x 10 10 W/m². The luminosity of the supernova is 6 x 10° Lo (or 6 x 10° solar luminosities). What is the distance to the supernova in parsecs? Take 1 pc = 3.0857 x 1016 m and Lo= 3.828 x 1026 w. d = pc

= 2000 K and a radius of R, A young recently formed planet has a surface temperature T Jupiter radii (where Jupiter's radius is 7 x 107 m). Calculate the luminosity of the planet and 2 determine the ratio of the planet's luminosity to that of the Sun.

Say that a white dwarf has about the same radius as the earth and about the same mass as the sun. Quantitatively compare the bulk density of the white dwarf to the bulk density of the sun.

The rate at which a nebular cloud rotates increases as the cloud collapses to form systems of stars and planets. Consider a small segment of a nebular cloud with a mass m of 1.9 x 102" kg, tangential velocity vinitial equal to 6.8 km s-1 located at an orbital distance rinitial = 2.5 x 10* km. After the cloud collapses, the same small segment is located at an orbital distance rinal = 3.2 x 10° km. Calculate the change of the rotational velocity, Ao, for the cloud segment, assuming perfectly circular orbits. Perform your work and report your solution using two significant figures. Δω- 16605 rad s-!