Astronomy | Astrophysics Answers

The sun and other stars do not shine as a result of nuclear reactions deep in their interiors
Is these true or false

Gerard Kuiper belt proposed that certain comets come from vast, extremely distant, spherical shell of icy bodies surrounding the solar?
Is it True or false

1.1 define milky way galaxy.
1.2 defferentiate between equinox and solstice.
1.3 use a diagram to explain what the kuiper belt is.

Define the following scientific terms.
A, solar system
B, moon
C, universe
D, lithosphere
E,atmosphere

2.2 how many planets are there in the solar system?
2.3 which planet is closest to the sun?
2.4 which planet has the largest ring system?
2.5 what is the largest terrestrial planet?
2.6 what is the only known moon of pluto?
2.7 what is the earth's radius?
2.8 where do most comets arrive from?
2.9 which is shorter, Mercury's day or year?

1.1 which planet is closest to the sun?
1.2 how many planets are there in the solar system?
1.3 which planet is not a terrestrial planet?
1.4 how many moons does jupiter have?
1.5 what is the smallest planet?

Indicate the following statement is true or false.
2.1 elliptical galaxies are shaped as their name suggests.
2.2 Gerard kuiper belt proposed that certain comets come from a vast, extremely distant, spherical shell of icy bodies surrounding the solar system.
2.3 the sun and other stars do not shine as a result of nuclear reactions deep in their interiors.
2.4 there are actually three theories of relativity.
2.5 newton's law of gravitation, when combined with his second law of motion,shows that objects with different masses fall at the same rate.

Discuss the important discoveries in astronomy by different people in the last 100 years.

Discuss the important of discoveries in astronomy by different people in the last 100 years

what's the mas of the black hole m87?

Because you are moving with an enormous speed, your mission from the previous problem A.1
will be influenced by the eects of time dilation described by special relativity: Your spaceship
launches in June 2020 and returns back to Earth directly aer arriving at Sirius.
(a) How many years will have passed from your perspective?
(b) At which Earth date (year and month) will you arrive back to Earth?

The most mass of our Milky Way is contained in an inner region close to the core with radius R0.
Because the mass outside this inner region is almost constant, the density distribution can be
written as following (assume a flat Milky Way with height z0):
ρ(r) = (
ρ0, r ≤ R0
0, r > R0
(a) Derive an expression for the mass M(r) enclosed within the radius r.
(b) Derive the expected rotational velocity of the Milky Way v(r) at a radius r.