Astrophysics & Cosmology - exam practice

Which is the most likely evolution of a star that is 10 times more massive than our Sun?

The parallax angle for a star is 0.015 seconds of arc.

What is the distance in parsecs (pc) of the star from Earth?

A spectral line corresponds to a wavelength ${\lambda }_1$in the laboratory.

The same spectral line observed in the spectrum of a receding galaxy corresponds to a wavelength ${\lambda }_2$.

The distance of the galaxy from the earth is d. The speed of light in a vacuum is c.

What is the correct expression for the Hubble constant H_0_?

Which of the following is the greatest astronomical distance?

A hot metal emits a black-body spectrum. The luminosity of the metal at 800 °C is L.

What is the luminosity of the metal when at 1000 °C?

Some stars will evolve into white dwarfs.

The mass of the sun is 2.0 x 10³⁰ kg.

Which of the following cannot be the mass of a white dwarf?

An astronomer analyses light from a distant galaxy.

One of the spectral lines in the spectrum observed from the galaxy has wavelength 610 nm.

The same spectral line has a wavelength of 590 nm when measured in the laboratory.

What is the speed of this galaxy?

Betelgeuse is a star in the constellation or Orion which astronomers think could undergo a supernova explosion.

What could Betelgeuse evolve into following the supernova stage?

The intensity against wavelength graph of an object at 750°C peaks at a wavelength of $\lambda$. The temperature of the object is raised to 960°C.

What is the wavelength now at the new peak intensity in terms of $\lambda$?

Which two quantities are related in Hubble's law?