Astronomy | Astrophysics Answers

The star of a distant solar system explodes as a supernova. At the moment of the explosion, an resting exploration spaceship is 15 AU away from the shock wave. The shock wave of the explosion travels with 25000 km/s towards the spaceship. To save the crew, the spacecraft makes use of a special booster that uniformly accelerates at 150 m/s2 in the opposite direction. Determine if the crew manages to escape from the shock wave. (Neglect relativistic effects.)

  Suppose a new planet is discovered in circular orbit about the Sun with a period of 512 years. Find the radius of the orbit.  

An astronaut working on the Moon tries to determine the gravitational constant G by throwing a Moon rock of mass m with a velocity of v vertically into the sky. The astronaut knows that the Moon has a density ρ of 3340 kg/m3 and a radius R of 1740 km.

(a) Show with F = G · mM/ R²  that the potential energy of the rock at height h above the surface is given by: E = − (4πG /3) mρ · R³ / (R + h) (2)

(b) Next, show that the gravitational constant can be determined by: G = 3v² /(8π x ρR²) (1 − R /(R + h)^-1 (3)

(c) What is the resulting G if the rock is thrown with 30 km/h and reaches 21.5 m?

Which very intense meteor shower is taking place annually in December?

What kind of celestial object is Neowise C/2020 F3 and what makes it special?

Where in the night sky can you observe the famous double star system Mizar and Alcor?

Approximately how many stars are visible with the naked eye in the night sky?

Radio telescopes are an essential tool for modern astrophysics. They played a crucial role in discovering a fascinating astronomical object: Pulsars - highly compact objects that periodically emit radiation. Pulsars are still an active part of astrophysical research. Explain how pulsars are formed and the causes for their pulsating behaviour.

A research team has discovered that a moon is circling a planet of our solar system: The moon orbits the planet once every 7 hours on a nearly circular orbit in a distance R of 48000 km from the centre of the planet. Unfortunately, the mass m of the moon is not known. Use Newton’s law of gravitation with G = 6.67 · 10⁻¹¹ m³ /(kg·s² ) to approach the following questions: F = G · mM / R²

(a) Based on the observations, determine the total mass M of the planet.

(b) Which moon and planet of our solar system is the team observing? (Use literature.)

The star of a distant solar system explodes as a supernova. At the moment of the explosion, an resting exploration spaceship is 15 AU away from the shock wave. The shock wave of the explosion travels with 25000 km/s towards the spaceship. To save the crew, the spacecraft makes use of a special booster that uniformly accelerates at 150 m/s2 in the opposite direction. Determine if the crew manages to escape from the shock wave. (Neglect relativistic effects.)